MEMORANDUM Subject: Response to Public Comments on Proposed Standards of Performance for Stationary Compression Ignition Internal Combustion Engines

From: Jaime Pagán, SPPD - Energy Strategies Group

To: EPA Docket EPA-HQ-OAR-2005-0029

On July 11, 2005, EPA proposed standards of performance for stationary compression ignition (CI) internal combustion engines (I CE) in 40 CFR part 60, subpart IIII. The purpose of this document is to present a summary of the public comments that EPA received on the proposed standards and the responses developed. This summary of comments and responses serves as the basis fo r revisions made to the standards between proposal and promulgation. EPA received 47 public comments on the propos ed rule. A listing of all persons submitting comments, their affiliation, and the Document ID for their comments is presented in Table 1. The comments can be obtained online from the Federal Docket Management System at http://www.regulations.gov . The docket number for this rulemaking is EPA-HQ-OAR-2005-0029. In this document, commenters are identified by the last three digits of the Document ID of their comments.

1Table 1. List of Commenters on the Proposed Standards of Performance for Stationary Compression Ignition Internal Combustion Engines

Document ID 1 Commenter/Affiliation EPA-HQ-OAR-2005-0029-0214 Jon D. Beddington Senior Engineer/Supervisor Earthtech EPA-HQ-OAR-2005-0029-0217 Stephanie R. Meadows Upstream Coordinator American Petroleum Institute EPA-HQ-OAR-2005-0029-0218 Gordon Gerber Caterpillar, Inc. EPA-HQ-OAR-2005-0029-0219 2 The Engine Manufacturers Association (EMA)

EPA-HQ-OAR-2005-0029-0220 Dr. Roger Saillant President and CEO Plug Power EPA-HQ-OAR-2005-0029-0223 Robert D. Haggard Washington Group International EPA-HQ-OAR-2005-0029-0224 Stephen W. McCluer Project Engineer American Power Conversion Corporation EPA-HQ-OAR-2005-0029-0225 Jerry D. Ogan Director Facilities Services & Safety Officer St. Francis EPA-HQ-OAR-2005-0029-0226 Miratech Corporation EPA-HQ-OAR-2005-0029-0227 EPA-HQ-OAR-2005-0029-0228 Andrew Wallo Director Department of Energy EPA-HQ-OAR-2005-0029-0229 Robert Rosner Director Argonne National Laboratory EPA-HQ-OAR-2005-0029-0233 Kurt Fredriksson Commissioner Alaska Department of Environmental Conservation EPA-HQ-OAR-2005-0029-0234 Alfred K. Bohn, PE HMH Consulting, LLC EPA-HQ-OAR-2005-0029-0235 The European Association of Internal Combustion Engine Manufacturers (EUROMOT) EPA-HQ-OAR-2005-0029-0236 W. Thomas Schipper President American Society for Healthcare Engineering (ASHE) EPA-HQ-OAR-2005-0029-0237 Duplicat e comment, see OAR-2005-0029-0236

2Document ID 1 Commenter/Affiliation EPA-HQ-OAR-2005-0029-0238 James Ralston, P.E. Director, Bureau of Air Quality Pl anning Division of Air Resources New York State Department of Environmental Conservation EPA-HQ-OAR-2005-0029-0239 Nationa l Diesel Corporation

EPA-HQ-OAR-2005-0029-0240 Joseph L. Sucheki, Director, Public Affairs Timothy A. French, Legal Counsel The Engine Manufacturers Association (EMA) EPA-HQ-OAR-2005-0029-0241 Kirk J. Thomson Director, Environmental Affairs The Boeing Company EPA-HQ-OAR-2005-0029-0242 Phil Karris Vice President Energy Alternatives

EPA-HQ-OAR-2005-0029-0243 Environmental Defense – Dr. Ja na Milford and Janea Scot Natural Resources Defense Council – Rick Kassel Izaak Walton League of America – Mr. William Grant American Lung Association of Metropolitan Chicago – Brian Urbaszewski Wyoming Outdoor Council – Bruce Pendery Galveston-Houston Association for Smog Prevention (GHASP) – John D. Wilson Southern Alliance for Clean Energy – Anne Gilliam San Juan Citizen Alliance – Dan Randolph EPA-HQ-OAR-2005-0029-0244 Dale McKinnon Executive Director Manufacturers of Emission Controls Association EPA-HQ-OAR-2005-0029-0245 Also supports comments of 240 Richard A. Bishop Environmental Compliance John Deere Power Systems John Deere Product Engineering Center EPA-HQ-OAR-2005-0029-0246 Anonymous commenter

EPA-HQ-OAR-2005-0029-0247 John F. Kuterbach Manager State of Alaska Department of Environmental Conservation Division of Air Quality Air Permits Program EPA-HQ-OAR-2005-0029-0248 John Whitney VP Engineering Clarke Fire Protection Products, Inc. EPA-HQ-OAR-2005-0029-0249 Joe Jobe Executive Director National Biodiesel Board EPA-HQ-OAR-2005-0029-0250 Valerie Ughetta Director of Stationary Sources Alliance of Automobile Manufacturers

3Document ID 1 Commenter/Affiliation EPA-HQ-OAR-2005-0029-0251 Donald R. Schregardus Deputy Assistant Secretary of th e Navy (Environment) Department of the Navy EPA-HQ-OAR-2005-0029-0252 Duplicat e comment, see OAR-2005-0029-0242

EPA-HQ-OAR-2005-0029-0253 David Hansell Sr. Environmental Engineer, P.E. EM-Assist, Inc.

EPA-HQ-OAR-2005-0029-0254 Also supports comments of 264 Aaron Kleinbaum Assistant General Counsel and Dire ctor of Environmental, Safety and Health William F. Lane Counsel Ingersoll-Rand Company EPA-HQ-OAR-2005-0029-0255 Eric P. Yould Executive Director The Alaska Power Association (APA) EPA-HQ-OAR-2005-0029-0256 Thomas R. Weeks Chief, Engineering San Diego Air Pollution Control District EPA-HQ-OAR-2005-0029-0257 Duplicat e comment, see OAR-2005-0029-0256

EPA-HQ-OAR-2005-0029-0258 Bradley C. Thomas Sr. Environmental Engineer Alyeska Pipeline EPA-HQ-OAR-2005-0029-0259 Stephanie R. Meadows Upstream Coordinator The American Petroleum Institute (API) EPA-HQ-OAR-2005-0029-0260 Patti Krebs Executive Director The San Diego Industrial Environmental Association EPA-HQ-OAR-2005-0029-0261 Lisa S. Beal Director, Environment and Construction Policy The Interstate Natural Gas A ssociation of America (INGAA) EPA-HQ-OAR-2005-0029-0262 Leonard N. Helms Air Program Manager Tetra Tech EPA-HQ-OAR-2005-0029-0263 Daniel E. Donohue Chief, Emissions Assessment Branch, Stationary Source Division California Air Resources Board EPA-HQ-OAR-2005-0029-0264 Also supports comments of 219 Herb Whittall EGSA Technical Advisor The Electrical Generating Systems Association (EGSA)

4Document ID 1 Commenter/Affiliation

EPA-HQ-OAR-2005-0029-0265 William O’Sullivan, P.E. Director The State of New Jersey Department of Environmental Protection Air Quality Permitting Program EPA-HQ-OAR-2005-0029-0266 Liz Moyer TI ESH Manager Texas Instruments Incorporated EPA-HQ-OAR-2005-0029-0267 Bryan Brendle The National Associatio n of Manufacturers EPA-HQ-OAR-2005-0029-0268 Richard Huth National Diesel Corporation EPA-HQ-OAR-2005-0029-0269 Anonymous commenter EPA-HQ-OAR-2005-0029-0270 (late public comment) Mason Griffin Director, Environmental Health and Safety Bell South EPA-HQ-OAR-2005-0029-0271 (late public comment) Robert L. Greene, Ph.D.

1 EPA-HQ-OAR-2005-0029-0215, 0216, 0221, 0222, 0230, 0231, and 0232 are non-comment items submitted to the docket. 2 Comments submitted by EPA-HQ-OAR-2005- 0029-0219 are included in EPA-HQ-OAR-2005- 0029-0240.

5Summary of Public Comments and Responses The summary of public comments and responses is organized as follows:

1.0 Applicability/Effective Date

2.0 Modeling Mobile Source Program 2.1 Foreign Strategy to Stationary Sources 2.2 Size Threshold 2.3 Useful Life 2.4 Other

3.0 Testing and Maintenance Restrictions for Emergency Engines

4.0 Fuel Requirements 4.1 General 4.2 Alaska 4.3 Engines with a Displacement of ≥ 30 Liters per Cylinder 4.4 ULSD and Older Engines 4.5 Add-on Controls

5.0 Test Methods

6.0 Flexibility/ABT

7.0 Compliance 7.1 Following Manufacture r’s Instructions 7.2 Pre-2007 Model Year Engines and E ngines that Conduct Performance Testing 7.3 Load 7.4 Engines with a Displacement of ≥ 30 Liters per Cylinder 7.5 Startup, Shutdown, and Malfunction

8.0 Add-on Controls

9.0 Research and Development

10.0 Definitions 10.1 Emergency 10.2 Stationary Internal Combustion Engine

11.0 Rule Structure

12.0 Labeling

13.0 Recordkeeping and Reporting

613.1 Certification Records 13.2 Hour Meter and Other Compliance Re quirements for Emergency Engines 13.3 Notifications

14.0 Fire Pumps

15.0 Prior Tier Certification Requirements

16.0 Emission Standards 16.1 Emergency Engines 16.2 Engines >750 hp 16.3 Engines <75 hp 16.4 Engines with a Displacement of <30 Liters per Cylinder 16.5 Engines with a Displacement of ≥ 30 Liters per Cylinder

17.0 Peak Shaving

18.0 Need for Regulation

19.0 Costs

20.0 Health/Environmental Impacts

21.0 Other 21.1 Public Comment Period Extension 21.2 Corrections Needed 21.3 Format of Standards 21.4 Military Training Engines 21.5 Replacement Engines 21.6 Temporary Engines 21.7 Adjustments 21.8 Biodiesel 21.9 Dual-Fuel 21.10 SI NSPS 21.11 Test Cells

1.0 Applicability/Effective Date

1.1 Comment : One commenter (240) said that EPA is proposing to impose regulatory requirements on pre-2007 model year (MY) en gines as of April 1, 2006, a date that is expected to precede the publicati on of the final rule. This undermines and is inconsistent

with the notice and comment re quirements of the Administrative Procedures Act, as well

7as the Clean Air Act (CAA) section 111(b)(1)(B). Rule requirements before the

finalization of the New Source Performa nce Standards (NSPS) are inherently problematic. The commenter stated that by imposing regulatory requirements on engine manufacturers, entities that centrally produce pr oducts at manufacturing facilities that are separate and distinct from where such engi nes may later be installed and operated, EPA

has acted in contravention of manufacturers’ fundamental ri ghts to administrative due process. The commenter specifically objected to the violation of the notice and comment requirements of Federal law that is inherent in the proposal.

Response : EPA worked with industry and th e commenter, Engine Manufacturers Association (EMA), was directly involved in the rulemaking process. Regarding the comment that requirements begin as of Ap ril 1, 2006, the rule will not be effective until after it is published in the Federal Register. Manufacturer s and others have had a full opportunity for notice and comment. It is true that certain requirements will apply to engines manufactured prior to th e publication date. This is fully consistent with the specifications in section 111(b)(1)(B), which requires EPA to promulgate standards of performance for new sources in listed categ ories of stationary sources, and section 111(a)(2), which defines “new source” to m ean “any stationary source, the construction

or modification of which is commence d after the publicati on of regulations (or, if earlier, proposed regulations) , prescribing a standard of perf ormance under this section which will be applicable to such source.” [emphasis added]. There can be no question that an engine manufactured after April 1, 2006, wa s constructed or modified after the publication of the proposed regulations , which were published on July 11, 2005.

8Moreover, the requirements for engines manu factured prior to the 2007 MY do not even apply to manufacturers, but apply solely to owners and operators, who can meet such requirements either through purchase of an engine that meet s the requirements or through actions taken when placing the engine into service. EPA also met with EMA several times prior to proposal and EPA was informed by EMA that the standards that would be proposed for pre-MY 2007 engines were f easible in the timeframe provided. Regarding the comment that EPA has acted in contravention of manufacturers’ due process rights, EPA disagrees. First, as noted above, no entity is subject to the regulations until after publication of the final rule and manufacturers in particular are not subject until the 2007 MY. It is not clear how manufacturers were not afforded due process or how the proposal violated notice and comment requirements. EPA allowed for full notice and comment and EMA in particul ar was provided nume rous opportunities to provide input into the rulemaking process. Nor does EMA provide any justification for stating that by imposing requireme nts on manufacturers, we have violated their rights to due process. Manufacturers have been regulated for many years under various EPA requirements and there is no question they are subject to regula tion under the CAA. EMA does not claim that section 111 prevents regulation of manuf acturers. As EPA noted in the proposal, secti on 111 provides broad authority for EPA to promulgate new source performance standards and EPA believes that applying such standards to engine

manufacturers is reasonable in this instan ce. Indeed, EMA has expressed on several occasions that it is in general agreement w ith EPA that it is appropriate to regulate new stationary CI engines by adopting similar requirements that apply to nonroad mobile source engines through a certification program . EMA has stated that this ensures

9technologically feasib le and cost-effective emissions reductions from stationary CI engines. EPA believes it is appropriate to impose regulatory re quirements on engine

manufacturers and also thinks th at this is technologically feasible and provides the most cost-effective approach for reduc ing emissions from stationary CI engines. As stated in the proposal, a large majority of stationary CI engines are consumer products produced in mass quantities. EPA believes that the knowledge gained by manufacturers through a certification program for nonroa d CI engines can be applie d to implement an equally successful program for stationary CI engines. This also reduces bur den on the individual owner and operator.

1.2 Comment : One commenter (258) expressed that the applicability of the rule to engines manufactured before 2007, but permanently installed in a faci lity between July 11, 2005 and 2007 is unclear. The commenter as ked what is the practical (or emission limitation) significance of the date July 11, 2005. It seems the rule has no requirements for engines installed, modified, or recons tructed between July 11, 2005 and April 1, 2006, according to the commenter. The commenter furthe r noted that it is true that the rule will require engines modified or reconstructed after July 11, 2005 to comply with emission standards applicable to ne w engines of the same MY, but the substance of this requirement is not clear. The commenter co uld find no emission standards in the rule for engines of MY preceding April 1, 2006. The commenter requested that the rule be clarified in this regard or, perhaps explic itly simplified to require nothing of engines manufactured prior to April 1, 2006.

10Response : The rule applies to owners and opera tors of engines that are modified or

reconstructed after the date th e rule was proposed, i.e., July 11, 2005. Therefore, the rule does have requirements for engines modified or reconstructed between July 11, 2005 and April 1, 2006. The rule applies to owners and operators of new engines that are constructed after July 11, 2005, but not if the new engines were manufactured prior to April 1, 2006. Therefore, it is true that the rule has no requirements for engines that are constructed between July 11, 2005 and April 1, 2006. The significance of the date July 11, 2005 determines when modified and recons tructed engines become subject to the rule. Engines that are modified or reconstr ucted must meet the emission standards for the MY in which the engine was manufactured. For example, if a 1999 MY engine is modified or reconstructed after July 11, 2005, this engine would have to meet the emission standards that would apply to the 1999 MY engines under this rule, i.e., the pre2007 MY emission standards in table 1 of th e proposed rule. EPA agrees with the

commenter that it would be a ppropriate to clarify the appli cability of the rule and has

made this clarification in the final rule.

1.3 Comment : Two commenters (234, 258) said that th e word “install” is not specifically defined in §60.4216 of the proposed rule. Comme nter 234 said that the word “install” in §60.4208 of the proposed rule should be repl aced by the more accurate term “commenced construction” consistent with the regu latory definition in 40 CFR 60.2 and 40 CFR 52.21(8) and (9) and that this will eliminat e any ambiguities for regulatory agencies and owners/operators.

11Response : EPA does not believe it is appr opriate to use the term “commenced construction” instead of “install” in §60.4208 of the rule, and has retained the term “install” in the final rule. The purpose of this provision is to ensure that older engines meeting less stringent standards are no longe r installed by owners and operators after a reasonable period of time has elapsed once e ngine manufacturers begin making cleaner engines. In §60.4208 of the final rule, EPA is providing up to 24 months for owners and operators to install stationary engines produced in a previous model year that do not meet the applicable requirements for that pa rticular model year (see comment 1.4). Commencing construction has been define d in the General Provisions to include commencing a contract to build, which would ca use the requirements of this section to be delayed even further, and would al so be more difficult to enforce

. For that reason, EPA believes it is more appropriate to use the term “install” rather than “commenced construction.” We believe 24 months is enough time for an owner or operator to install an engine that is not a clean as engines bei ng manufactured at that time. For the purposes of this rule, the term “install” refers to the da te the engine is installe d at the operator site. EPA believes that using the term “install” is clear to owners and operators complying

with the rule and eliminates confusion with respect to the General Provisions.

1.4 Comment : One commenter (240) expressed th at the 6-month installation date deadlines in §60.4208 of the proposed rule are problematic and unworkable. The period of time between the manufacture of a stationary CI engine and its inst allation is regularly

in excess of 6 months. The NSPS should inco rporate the relevant anti-stockpiling from the nonroad rule (40 CFR 89.1003(b)(4)) instead.

12Another commenter (248) said that §60.4208(a) of the proposed rule does not exclude fire pumps (emergency CI ICE), but §60.4208(c) through (f) of the proposed rule does. A 6-month time limitation will become probl ematic, the commenter said. Due to construction project complexities, size and de lays, National Fire Protection Association (NFPA) certified fire pump engines may not be installed for as long as 1 year after the date of sale by the NFPA certifier. The NFPA certified fire pump engines are typically not purchased for inventory, and therefore, are self regulated by the da te of manufacturer. The commenter stated that fire pump engine s should be exempt from this fixed time

restriction.

Response : EPA agrees with the commenters that the 6-month deadline for installing engines of a previous tier is not long enough to allow for the time that typically can elapse between order and insta llation of an engine and may prevent engine manufacturers from using up existing inventories of engines. Therefore, EPA increased the time limit to 24 months after the beginning of the calendar year coinciding with the applicable MY. EPA has also included anti-stockpiling provi sions similar to those used for nonroad engines to prohibit stockpiling of previous tier engines in th e final rule. Also, EPA was concerned about imports of non- compliant stationary CI engi nes and has made it clear in §60.4208 of the final rule that the limitations of that section apply to imports of engines with a displacement of less than 30 liters per cylinder also. Engines with a displacement greater than or equal to 30 liters per cylinder are not include d in this provision since compliance with the emission standards for those engines can only be demonstrated

13through on-site stack testing. Fi nally, EPA has exempted stationary emergency fire pump engines from the deadlines in §60.4208(a) and (b ) of the final rule to account for the fact that fire pumps have different timing require ments for the emission standards they have

to meet.

1.5 Comment : One commenter (258) said that it maintains several engines for use at

various locations. It is con ceivable that the commenter ma y opt to permanently install one of these engines at one of its facilities in the future. Th e rule would seem to prohibit this, even though the engine wa s in the company’s possessio n long before the rule was drafted. One reason for concluding this is that §60.4208(a) of the proposed rule states that “owners and operators may not install pr e-2007 MY stationary CI ICE after June 30, 2007.” The commenter could find no explanation for this and stated that such a ban is excessively restrictive. The commenter reque sted that the rule allow flexibility for owners/operators to install engines it already owns even after 2007. If EPA is opposed, the commenter asked that EPA please provide an explanation in the final rule preamble.

Response : EPA contacted the commenter for clarification on this comment. The commenter indicated that it has nonroad engi nes that may remain in one location for more than 1 year, in which case these engines would be considered stationary engines. The commenter was referring to engines it al ready possesses and uses. It appears that this commenter misunderstood the provision s in §60.4208 of the proposed rule and was under the impression that thos e provisions would apply to any pre-2007 MY engine, not just pre-2007 MY engines that are subject to the rule, i.e., new engines that are

14manufactured after April 1, 2006 and engines that are modified or reconstructed after July 11, 2005. If the engine in question is manufact ured prior to April 1, 2006, it would not be subject to the rule and subs equently not subject to the requirements in §60.4208 of the proposed rule unless it is modified or r econstructed. Moreov er, §60.4208(g) explicitly exempts modified and reconstructed engines from the requirements of that section. Additionally, it was not EPA’s in tention to apply the restri ctions in §60.4208 to engines that had been previously used and reinstalle d in a different locati on. EPA has clarified this issue in the preamble and regulations in the final rule.

1.6 Comment : One commenter (258) requested clar ification on what is meant in all references to “pre-2007” or “pre-2008,” etc ., in the proposed rule. Given the bans in §60.4208 of the proposed rule, the commenter requested that EPA specify how this paragraph and any other similar paragra phs would even apply after June 30, 2007.

Response : A “pre-2008” MY engine is an engine that has a MY of 2007 or earlier. Similarly, a “pre-2007” MY engine is any engi ne that has a MY of 2006 or earlier. EPA

feels that this is clear in the rule and no furt her clarification is necessary. The rule applies to pre-2007 MY engines that are manufactured after to April 1, 2006 or modified or reconstructed after July 11, 2005.

1.7 Comment : One commenter (238) was of th e opinion that the deadlines for purchasing engines produced in a previous MY may be too restrictive and counterproductive. If an engine from a previous MY is in complia nce with the limits for the

15current MY engines, with or without post-co mbustion control, there is no reason to ban the purchase of such engine. If the lim its are based upon the date operation commences (the approach proposed in a distributed gene ration rule being developed by the New York Department of Environmental Conservation (NY DEC) (6 NYCRR part 222) anticipated to take effect on May 1, 2006), §60.4208 of th e proposed rule would be unnecessary.

Response : EPA believes that it is appropriate to base the limits on the MY of the engine. This is consistent with the approach used for nonroad engines and helps to make the process for certifying stationary engines easier for engine manufacturers, since many engines are used for both stationary and nonr oad applications. The proposed limits on purchasing and installing previ ous MY engines were limited to specific situations when

new emission standards would come into e ffect in the new MY. As discussed above, EPA is revising the language in §60.4208 to provide more time for owner/operators to install older engines and to prohibit manufacturers from st ockpiling older engines when a new set of emission standards is coming into e ffect. EPA agrees with the commenter that if an engine from a previous MY is in co mpliance with the limits for the current MY engines it can be installed. EPA has modi fied the language in the final rule to

accommodate this.

1.8 Comment : One commenter (264) was concerned with the inadequate lead time that the proposed NSPS affords nonvertically integr ated equipment manufacturers. In the commenter’s experience, it takes a minimum of 18 months from the time an equipment manufacturer receives a prot otype engine to incorporat e the engine into a final

16marketable product. The commenter noted th at in the nonroad rules, EPA has provided flexibility provisions that ease the trans ition for equipment manuf acturers when new emission standards take effect. However, the proposed NSPS does not include any flexibility for equipment manufacturers. The commenter believed that the NSPS

standards should take effect 18 months af ter promulgation of the final NSPS or 18

months after the effective date of the co rresponding nonroad standa rds, whichever is

later.

Response : The regulations for stationary CI engines do not apply to equipment manufacturers directly. The only possible effect is on owne rs and operators downstream. However, the emission standards are directed to MYs, which are determined at the time of engine manufacture, so any lag time is irrelevant. The only exception is in §60.4208 of the final rule, where EPA has provided a dditional time. The commenter refers to prototype engines. Prototypes are usually de veloped well before an engine is actually manufactured. The important cr iterion is the MY of the engi ne, not when the prototype is built. Regarding the comment about lead time, the initial standard s for stationary CI engines are less stringent than current nonroa d standards for CI engines and do not apply to engine manufacturers, but to owners and operators. The standards that begin with 2007 MY engines are applicable to engines beginning approx imately 18 months after the regulations were initially propos ed and are identical to (or less stringent than) standards for comparable nonroad engines and e quipment. Consequently, equipment manufacturers have been provided consid erable lead time to design equipment compatible with the certified engines. Again, however, EPA is not putting any

17requirements on equipment manufacturers, so they are under no time constraints except the one that apply to their s uppliers and customers. These constraints contain sufficient lead time and flexibility to deal with lag time between design of engine prototypes and manufacture of equipment. The issue of inco rporating the equipment flexibilities in the nonroad engine regulations is discussed in response to comment 6.2, which concludes that EPA believes that equipment manufacturers do not need those flexibilities in this rule because they are not regulated by this rule.

1.9 Comment : One commenter (265) recommende d that the NSPS regulate any nonemergency generator sets grea ter than 50 horsepower (hp). Distributed generation is becoming more common, and proliferation of small high emitting electric generators that are used in non-emergency situations should be avoided, the commenter said.

Response : EPA is regulating all new stationary engines, whether greater or less than 50 hp, and whether emergency or non-emergency.

1.10 Comment : One commenter (247) requested that the rule exempt area sources from the requirement to have a title V permit solely because of the presence of an affected engine.

Response : Section 502(a) of the CAA specifies th e sources that are required to obtain operating permits under title V. These sources include (1) any affect ed source subject to the acid deposition provisions of title IV of the CAA, (2) any major source, (3) any

18source required to have a permit under parts C or D of title I of the CAA, (4) “any other source (including an area source) subject to standards under section 111 (new source performance standards) or 112 (national emissions standards for hazardous air pollutants),” and (5) any other stationary s ource in a category de signated by regulations promulgated by the Administrator. Section 502(a) of the CAA also provides that the Administrator may “promulgate regulations to exempt one or more source categories (in whole or in part) from the requirements of this subsection if the Admi nistrator finds that compliance with such requirements is impracticable, infeasible , or unnecessarily burdensome on such categories, except that the Administrator ma y not exempt any major source from such requirements.” EPA has exempted many ar ea sources subject to section 111 or 112 standards from title V requirements in prior rulemakings, in particular see a recent final rule, 70 FR 75320, December 19, 2005, that provides additional background information and rationale for such exemptions for a la rge number of area sources subject to CAA

section 112 standards. In the case of affected stationary CI engines located at ar ea sources, EPA believes compliance with permit requirements under title V would be impracticable, infeasible and unnecessarily burdensome for the reasons explained below. First, title V permits would be unnecessa rily burdensome for area sources subject

to this final rule because title V woul d not result in significant improvements to compliance with the CAA section 111(b) standard for the area sources. (The term “title V permits” used here refers to permits issu ed under 40 CFR parts 70 or 71 by either a State or local agency or EPA.) For a great number of these area sources, these engines

19are the only emission source and the owner/operator (often a hospital or a school) will not be at all familiar with the requirements fo r permits. To demonstrate compliance with these section 111(b) standards, the final rule requires the ow ner or operator of the area source to purchase a certified stationary CI engine. Certification that the engine meets the emission reduction requirements of this fi nal rule is done by the manufacturer of the engine, rather than the area sour ce that owns or operates the engine. This strategy places a significant amount of responsibility fo r compliance with the standard on the manufacturer, compared to many other emi ssion standards that place the compliance responsibility on the owner or operator. EPA believes this strategy is the most effective way to ensure that the standard is met during the useful life of the engine. Also, title V would not result in significan t improvements to compliance with the standard for these area sources because the section 111(b) sta ndard itself contains adequate compliance requirements for these area sources, consistent with the CAA, without relying on title V. Second, title V would impose certain burdens and costs on area sources subject to

this final rule that EPA does not believe are justified when compared to the potential for title V permits to improve compliance with the CAA section 111(b) standards for such sources. This is so because EPA believes the costs and burdens of title V permits for the typical area sources subject to th is final rule would be signific ant. This assessment is not based on any particular empirical data or study but on a review of the types of standalone area sources that would be subject to this final rule , for example, small farming operations using diesel engines for irri gation purposes and small businesses and residential homeowners using diesel engines for back-up el ectrical power generation. (See current ICR for 40 CFR part 70, EPA ICR # 1587.06 and OMB control number

202060-0243 for EPA’s best estimate of the burdens and costs of title V for sources subject to 40 CFR part 70 on a national, aggregate ba sis.) Also, as explained above, EPA’s judgment is that requiring operating permits for these area sources would not result in significant improvements to compliance over that already required by this final rule. Thus, the burdens and cost of title V permits for these area sources would be significant, and in any case, they will be unnecessary a nd not justified, when compared to the low potential for title V permits to improve comp liance, consistent with the “unnecessarily burdensome” criterion of section 502(a) of the CAA. The strategy of this final rule, requi ring the manufacture of cleaner burning emission sources (manufacturer-based cont rols), has been employed in other CAA section 111 standards, for example, the N SPS for new residential woodstoves (subpart AAA of 40 CFR part 60). We exempted area sources subject to the woodstove NSPS in the final rule for 40 CFR part 70 (57 FR 32250, July 21, 1992) for reasons similar to those we describe today for stationary CI IC engines. (40 CFR 70.3(b)(4) and 40 CFR 71.3(b)(4).) Thus, we have decided to exempt area sources subject to this final rule from title V operating permit requirements under 40 CFR pa rt 70 and 40 CFR part 71, and we have changed the applicability language in the final regulations to specify this. Under this approach, title V exemptions are allowed for an area source, provided the area source is not required to obtain a permit under 40 CF R 70.3(a) or 40 CFR 71.3(a) for another reason, such as when the source becomes a majo r source. Also note that this exemption only affects whether an area source is require d to obtain an operating permit, it has no bearing on any other requirem ents of this final rule.

212.0 Modeling Mobile Source Program

2.1 Applying Strategy to Stationary Sources

2.1.1 Comment : One commenter (240) stated thatit supports the alignment of nonemergency stationary CI engine standards with the corresponding nonroad and marine CI engine standards. As a general matter, the commenter supports and agrees with the

emission standards and effective dates set forth in the proposal. Those proposed standards appropriately recognize that non-emergency sta tionary CI engines are derived from corresponding nonroad or marine CI engi nes, depending on thei r power ratings and displacement. The commenter also expre ssed support for the proposal’s recognition of

the relevant differences between the use and emissions capabili ties of non-emergency engines, on the one hand, and emergency engi nes and fire pump engines, on the other. Accordingly, the commenter also endorses those elements of the proposal that will:

(i) align the emission sta ndards for 2007 MY and later non-emergency stationary CI engines less than or equal to 3,000 hp and a displacement le ss than 10 liters per cylinder (l/cyl) with the Tier 2 through Ti er 4 nonroad diesel engine standards;

(ii) align the emission standards for 2011 MY and later non-emergency stationary CI engines greater than 3,000 hp and a displacement less than 10 l/cyl with the Tier 4 nonroad diesel engine standards;

22(iii) align the emission standards for pr e-2007 MY stationary CI engines with a displacement less than 10 l/cyl with the Ti er 1 nonroad diesel engine standards;

(iv) align the emission standards for 2007-2010 MY non-emergency stationary CI engines greater than 3,000 hp and a displacement less than 10 l/cyl with the Tier 1 nonroad diesel engine standards;

(v) align the emission standards for 2007 MY and later non-emergency stationary CI engines having a displacement greater than or equal to 10 l/cyl and less than 30 l/cyl with emission standards applicable to new marine CI engines; and

(vi) ensure that emergency stationary CI engines are not subject to emission standards (e.g., Tier 4-type standards) that would nece ssitate the installation and use of emissions aftertreatment systems.

The commenter stated that each of the foregoing elements of the proposal is a vital component of any rulemaking pertaining to sta tionary CI engines. Engine manufacturers do not separately design and produce non-em ergency CI engines for stationary applications. Instead, non-emergency stationa ry CI engines are de rived from CI engines that are designed and manufactured to comply with the relevant nonroad and marine CI engine emission requirements that EPA has established. The net result is that a nonemergency stationary CI engine is, in essence, nothing more than either a nonroad CI engine or a marine CI engine that is installed and operated in a stationary application.

23Because of this fundamental aspect of the non-emergency stationary CI engine industry,

the relevant benchmarks for the “best demons trated technology” must be the emission

standards that EPA has determined as setti ng the benchmarks of t echnological feasibility for nonroad and marine CI engines within the relevant range of power ratings and displacements. The commenter stated that the proposal is, at its core , guided by this basic principle, and so it is, at its core, a well-reasoned and sound rulemaking proposal.

Response : EPA generally agrees with the comment s provided and has continued to align the standards in the final rule with nonroad CI engine standards, as appropriate.

2.1.2 Comment : Two commenters (259, 261) stated th at the proposed standard layers mobile source requirements with similar 40 CFR part 60 requirements. These mobile legacy provisions, such as the General Pr ovisions and testing re quirements for nonroad engines, are foreign to stationary source ope rators. Two commenters (259, 260) said that a rule modeled after mobile standards is unnecessarily complex and includes requirements that are inconsistent with the le gacy of stationary s ources affected under 40 CFR part 60. One commenter (261) was c oncerned that an array of unforeseen implementation issues could arise in translati ng the mobile source criteria to stationary

sources.

One commenter (238) said that the limits are based upon the engine MY and could lead to confusion. Limits for stationary sources have in the past been based upon the date of construction or operation. Two adjacent facilities may install identical engines

24manufactured by different companies and are of different MYs. Th ese engines could be subject to different limits. The facility that is subject to the more stringent limits may challenge the fairness of the limits and the cost to comply with the more stringent limits. This can be avoided by establishing limits based upon the date a source commences operation. The commenter added that complia nce with NSPS limits is primarily based upon manufacturer guarantees. This is a new regu latory strategy for stationary sources. The NY DEC issues permits to facility owne rs/operators, which ar e contracts whereby the permittee agrees to comply with all applicable provisions. Manufacturers are not parties to permits issued by the NY DEC. Any violation of a permit condition is, therefore, the responsibility of the permittee. Any enfor cement action initiated by the NY DEC would be against the permittee, not the manufacturer. The NY DEC’s distributed generation rule (6 NYCRR part 222) is structured in this way. If an engine is not in compliance with the limits, the owner/operato r may have legal recourse against the manufacturer depending upon the conditions of a warranty. The NY DEC, not being a party to a warranty, would not have legal recourse against the manufacturer. This commenter recommended that the owner/opera tor be responsible for compliance with

emission limits under the NSPS.

Response : EPA disagrees with these commenters on certain issues. EPA agrees that aligning the NSPS with mobile standards and placing significant responsibility with manufacturer is somewhat unusual, but it is not an unprecedented regulatory strategy for stationary sources (40 CFR part 60, subpart AAA, Standards of Performance for New Residential Wood Heaters). EPA has determin ed that it is appropriate to develop a

25regulatory strategy for internal combustion en gines that is generally directed towards engine manufacturers. EPA r ecognizes that the proposed appr oach is different than the strategy typically followed in NSPS rulemaki ng for stationary sources, which is often aimed at the owners and operators of stationa ry sources. However, EPA has worked with engine manufacturers throughout the rule deve lopment process, and it was determined that developing a rule that will affect engine s at the manufacturing level, will achieve the best system of emission reduction while taki ng into account the cost of achieving such

reductions. The certification of nonroad diesel engines is a well-established program that engine manufacturers are familiar with. Engine manufacturers have indicated that they often design and manufacture th e same engines for nonroad use as for stationary use. As mentioned in the preamble to the proposed rule, the vast majority of stationary CI engines are consumer products produced in mass quantit ies. Internal combustion engines have traditionally been regulated through the manu facturer for purposes of meeting mobile source regulations. Manufacturers have extens ive experience with complying with such standards. It is also simpler, more reliabl e, and comparatively inexpensive to regulate stationary CI engines employing the same appro ach as for mobile sources than to create a new approach based on testing by every owner and operator. Moreover, EPA believes this method of regulation will be much easier for owners and operators (represented by the commenters) than a set of regulations aimed primarily at owners and operators. Th e commenters note that the pr oposed standards layer mobile source requirements on 40 CFR part 60 re quirements, but EPA’s mobile source regulations are directed towa rds manufacturers, so they wi ll not substantially affect owners and operators. In general, owners and operators will be required to purchase

26certified engines, which are likely to be the only new engines available, since

manufacturers will not be able to sell uncerti fied engines. This would seem to be preferable from an owner/operato r’s perspective than having to individually test all of its new engines initially and period ically thereafter to show compliance with the standards, and to engage in all of the other complianc e procedures normally required for stationary sources. While EPA acknowledges that this appr oach is one with whic h stationary source owners and operators may not be accustome d, EPA believes that this approach will provide less burden to owners and operators than a more standard NSPS approach. Regarding the comments from NY DEC, EPA believes that because the owner/operator will be purchasing certified e ngines, it will know prior to purchase and installation the emission limits and costs for the engine. A manufacturer would not be selling identical engines for different model years unless the engine met the standards for both model years, so there would be no in creased cost for the user. Un like in other re gulations, the emission-related costs are known from the outset, because they are inherent in the cost of the certified engine. The NSPS should have no effect on the manner in which NY DEC ensures compliance with its di stributed generation rule. However, as discussed below, owners and operators do have responsibilities under the NSPS, compliance with which can be readily determined. EPA agrees that it would be appropriate to specify what parts of the General Provisions apply to engines s ubject to subpart IIII of 40 CFR part 60. In the final rule, EPA has included a table lis ting which General Provisions from 40 CFR part 60, subpart A, apply to stationary CI engines subject to this subpart.

2.2 Size Threshold

272.2.1 Comment : Three commenters (259, 260, 261) said that the rule proposes regulation of equipment much smaller than typical fo r 40 CFR part 60 standards. Two of these commenters (259, 261) were of th e opinion that other than for manufacturer certification, engines 500 hp or less should be exempted and a size threshold should be added. Commenter 259 said that the rule, as propos ed, regulates all stationary CI engines regardless of size, which is inconsistent w ith established NSPS. Rationale must be provided for including smaller units and EP A must state its re gulatory intentions.

Response : EPA is required to regulate all source s in a source category unless there is a basis for not addressing all size units. Du ring the rule development process, EPA determined that it would be appropriate to regul ate all units. As stated in the preamble to the proposed rule, EPA estimates that approximately 81,500 new stationary CI ICE will become affected by the rule in the year 2015. Of these, more than 72,000 are below 500 hp and represent more than 50 percent of the total emissions emitted from new stationary CI engines. These engines, or engines similar to these engines, have already been regulated in the context of regulation of mobile sources and there is no reason not to regulate these engines here. Own ers and operators of these en gines, particularly smaller engines, are not subject to onerous requirements. In fact, after sta tionary CI engines are required to be certified, owners and op erators will have minimum compliance requirements beyond purchasing a certified e ngine. Owners and operators of certified engines would have to operate the engine acco rding to the manufacturer ’s instructions to demonstrate continuous compliance. Some owners would have additional monitoring

28requirements, such as recording the hours of operation, which is not a burdensome requirement and many sources may already be recording this information for other purposes. Thus, the burden on owners and operators is comparatively minimal under these regulations; however, as EPA must assure that certified engi nes are actually being installed and used, we must have some leve l of requirement on owners and operators. The commenter speculates that State and local agencies may institute further requirements on owners and operators, but Stat e and local agencies have always had the ability to regulate these engines, and some ha ve done so. The actions of these agencies should be judged on their own merits. The co mmenters provide no substantive reason to exclude smaller engines, incl uding those engines 500 hp or le ss, from this regulation, or to completely exempt owners and operator s from any responsibility in assuring that certified engines are purchased and operated according to manufacturer specifications.

2.2.2 Comment : Two commenters (259, 260) stated th at without a size threshold, title V permitting at major sources may require consideration of applicable requirements for very small units. The commenters suggest that no permitting requirements other than

manufacturer certification be re quired for these engines.

Response : As discussed under comment 1.10, th e final rule exempts area sources from title V permit requirements but it does not exempt major sources. Section 502(a) of the CAA requires all major sources to obtai n title V operating permits and it does not allow any major source to be exempted from title V. Also, 40 CFR 70.3(c)(1) and 40 CFR 71.3(c)(1) require permits for major source to include all applicable requirements,

29and any requirements of today’s final rule th at applies to a major source are applicable requirements and must be included in the permit. Additionally, it should not be a big burden on major sources to add these engines to their permits, given that they already have to fill out the permits. Thus, we di sagree with the comment er and we have not made the suggested change.

2.3 Useful Life

2.3.1 Comment : One commenter (238) noted that the manufacturer’s guarantees are good for the “useful life” of the engine. The us eful life of engines, as defined in 40 CFR parts 94 and 1039, range from 3 to 10 years. The useful life of a statio nary CI engine can

last for decades. The NY DEC estimates th at approximately 25 percent of the demand response sources in NY City and on Long Island are more than 25 years old. The oldest such engine is nearly 50 years old. Clearly, th e useful life of an engine, as defined by the

nonroad rules is too short. Sta tionary engines must be maintained such that they are in compliance with applicable emission standards for as long as they are in use in order to maintain compliance with permits.

Three commenters (259, 260, 261) note the introd uction of mobile source concepts such as “useful life.” Two commenters (259, 261) st ate that useful life, “includes time limits related to mobile operation that suggests inappropriate limitations for engines in stationary applications.” One commenter (259) st ates that this also raises questions about ongoing compliance certification for stationary engines ope rating beyond their “useful

30life.” States and local agencies may be compelled to institute additional compliance requirements for units that exceed their useful life. Since the propos al is silent on the issue of longer term complianc e, it leaves open the possibility that disparate requirements will expand across the U.S.

Response : EPA acknowledges that stationary dies el engines can last beyond the useful life as defined in §60.4219 of the proposed rule. It is true that sta tionary diesel engines can last more than the 3 to 10 years given in 40 CFR parts 94 and 1039. The useful life period is designed to represent the time during which the engine manufacturer is responsible for the engine meeting the emi ssion standards as long as the owner operates the engine according to the manufacturer’s sp ecifications. After the useful life of the engine, it is the owner or operator’s sole respon sibility to ensure that the engine continues to meet the emission standards. EPA expects that owners and operators will continue to operate regulated engines in a manner that provides for continued emissions control. Throughout the life of the engine, the owners and operators must operate and maintain the stationary CI engine and control devi ce according to the ma nufacturer’s written instructions (or procedures de veloped in cooperation with the engine manufacturer). The engine must also be installed and conf igured according to the manufacturer’s specifications. As noted above, State and loca l agencies are authori zed to regulate these engines beyond EPA’s NSPS requirements. If St ate and local agencies wish to institute additional compliance requirements for certified engines that operate beyond their useful life that is their pr erogative and such requirements s hould be judged on their merits.

312.4 Other

2.4.1 Comment : One commenter (240) expressed th at it generally agrees with the emission standards and effective dates of the proposal. The proposed standards appropriately recognize that non-emergency stationary CI engines are derived from corresponding nonroad or marine CI engine s, depending on their power ratings and displacement. The commenter also supported the proposal’s recogniti on of the relevant

differences between the use and emissions capabilities of non-em ergency engines and emergency and fire pump engines. The comme nter further expressed that as a general matter, the rule should not pull ahead any requirements derived from nonroad engine regulations in advance of th e applicability of those re quirements to the corresponding nonroad engines. Specifically, none of the requirements of new 40 CFR part 1068 should be applied to any stationary CI engines in advance of the applicability of the Tier 4 standards to such engines. The requirement s of 40 CFR part 89 (not 40 CFR part 1068) should be applied to stationary CI engines th at are subject to compliance with the Tier 1 through Tier 3 nonroad emission limits. Ot herwise, several of the regulatory requirements developed in the context of Ti er 4 nonroad engines wi ll end up being pulled ahead and imposed on stationary CI engines in advance of the applicability of the underlying Tier 4 emission limits, even to th e corresponding nonroad engines. Such a pull ahead would be contrary to the basic premise of the NSPS proposal, which is to apply nonroad engine requirements to stationary engines only as or after they are being phased in for nonroad engines and no earli er and would therefore be inherently

unreasonable.

32Response : EPA proposed that all engines shoul d meet part 1068 because EPA believed that the provisions in that pa rt were generally the same as those for the other parts. However, manufacturers have provided several examples of differences in the requirements in these parts and EPA believes that it is consistent with the intent of this rule that stationary engines meet the same compliance requirements as comparable nonroad engines. Therefore, EPA is fina lizing provisions that subject only part 1039 engines to part 1068; the engines subject to other parts will meet the compliance requirements applicable to engi nes subject to those parts. EPA has clarified this in the

final rule.

2.4.2 Comment : One commenter (243) stated that EPA’s overall approach of adopting Tier 4 equivalent engine standards implemented through a manufacturer certification program is appropriate and well-justified, and that promulgation of standards not as rigorous as Tier 4 would be arbitrary and capricious

.

Response : EPA agrees with the commenter’s view that using a manuf acturer certification approach, and requiring Tier 4 equivalent standards, is a ppropriate and well justified, though EPA does not necessarily believe that fa ilure to do so would have been arbitrary or capricious.

2.4.3 Comment : One commenter (259) was of the opinion that phase-in dates for lower emission standards should be preceded by a technology review to ensure that the

33proposed requirements are technically and economically feasible. The commenter specifically refers to the issue of fuel availabi lity in rural portions of Alaska. The initial phase of regulation should be associ ated with 2007 certified engines.

Response : EPA has thoroughly reviewed the feasib ility of the proposed standards in the context of previous nonroad engine rules. EPA firmly believes that these standards can

be achieved based on known demonstrated te chnology. For example, the particulate matter (PM) standards that will be im plemented in 2011 are based on the use of particulate filters that are currently in use in some applications and will likely be used by much of the on highway diesel industry when new standards for such engines take effect in 2007. The low sulfur diesel fuel necessary to meet these standards will be fully available by the time these later standards take effect. Indeed, ultra low sulfur diesel (ULSD) fuel will represent the vast majority of diesel fuel refined and distributed in the U. S., as a result of rules promulgated under title II of the CAA. EPA is planning to conduct a technology review in 2007 to address technology issues warranting such a review for nonroad engines below 75 hp. It is expected that the fi ndings of this review will apply to stationary engi nes as well. During the 2007 review, EPA will evaluate which long-term standards for PM are appr opriate for engines below 25 hp. Long-term NOx standards for engines below 75 hp will al so be reviewed to determine if more stringent standards are appropria te. Further information rega rding EPA’s future plans to conduct a technology review can be found in the material re lated to the 2004 nonroad CI engine rulemaking. Regarding the particular issue of rural Alaskan villages, please see the discussion in section 4.2 below. Regarding the suggestion that this rule should not be

34implemented until the certification requireme nts begin in 2007, the CAA requires that engines constructed after proposal of this re gulation are covered by the regulation. Given the difficulty of beginning a certification pr ogram without sufficient time to change manufacturing processes, there was a certain period where engines would be covered by standards, but engines certifie d to those standards would not necessarily be available. However, EPA has set the standards for these in terim engines at levels that are easily met with existing technologies and has provided numerous methods of compliance with these

standards that should ease th e burden on owners and operators during this interim period. EPA believes this interim program provides needed emission reductions without unduly burdening owners and operators during this period.

2.4.4 Comment : One commenter (264) was concer ned with incorporating Tier 4 requirements into the NSPS. Because aftertreatment technologies are still in the developmental stage, the commenter did not be lieve that those systems qualify as the best demonstrated technology (BDT) for NSPS. The commenter urged EPA to modify the NSPS. For engines less than 19 kilowatt (kW) (25 hp) the ultimate tier of standards should be Tier 4 standards that do not require aftertreatment controls. For engines rated between 19 and 37 kW (25 and 50 hp), the in terim Tier 4 standards should apply. Finally, for engines greater than 37 kW (50 hp) , the ultimate tier of standards should be

Tier 3.

Response : EPA believes that the proposed emissi on standards are appropriate and that the aftertreatment technologies that are the basis for the majority of the Tier 4 emission

35standards are suitable as BDT for this NSPS. As noted above, the standards are based on technologies that have been demonstrated to be effective in reducing emissions to necessary levels. Manufacturers have indicate d that for the most pa rt, emission standards

that are based on aftertreatment controls are achievable. The final tier of standards for stationary CI engines less than 19 kW (25 hp) do not rely on the use of aftertreatment controls. EPA does not agree that the interi m Tier 4 standard should act as the final emission standard for non-emergency engines between 19 and 37 kW (25 to 50 hp). The

final Tier 4 standard should be the final tier of standards for these engines. However, for emergency engines between 19 and 37 kW, the final emission standards are not based on aftertreatment controls. In general, for non-emergency engines greater than 37 kW (50 hp), the final tier of standards is Tier 4. For emergency engines greater than 37 kW (50 hp), the final tier of standards is the most stringent tier (usual ly Tier 3) prior to the tier that requires aftertreatment. The commen ter did not provide a ny rationale supporting these requests and EPA believes the emission st andards, as proposed, are appropriate.

2.4.5 Comment : One commenter (265) supported the proposed standards for stationary diesel engines being at least as stringent as for nonroad di esel engines. The commenter added that it believed that the proposed sta ndards for stationary sources can be more stringent than for mobile source engines becau se add-on controls are not restricted by the space limitations of mobile sources. Th e commenter recommended a limit of 0.15 grams per horsepower-hour (g/hp-hr) of NOx for all stationary diesel engines starting in 2011,

36after ULSD becomes available nationally. Th e commenter provided their State of the Art

manual 1 , which provides justification for this new source emission level.

Response : EPA must consider several aspects when developing emission standards for stationary engines, such as technical feas ibility and cost of requirements, and EPA’s considerations are not limited to space conc erns. EPA believes that the NOx emission standards in the proposed rule, which are ge nerally based on the em ission standards for nonroad diesel engines in 40 CFR parts 89 a nd 1039, are appropriate for stationary CI engines. Furthermore, since the rule relies in large parts on manuf acturer certification, and considering that engine manufacturer s often produce the same engines for nonroad and stationary use, requiring the same or similar emission standards for stationary engines that are required for nonroad engines is appropriate.

1 Section 3.13 State of the Art (SOT A) Manual for Reciprocating Internal Combustion Engines. Effective Date: 2003. State of New JerseyDepartment of Environmental Protection Division of Air Quality. Internet: http://www.state.nj.us/dep/aqpp /downloads/sota/sota13.pdf

.

373.0 Testing and Maintenance Restrictions for Emergency Engines

3.1 Comment : Several commenters (218, 223, 224, 225, 228, 234, 236, 238, 240, 241, 242, 246, 248, 250, 251, 253, 255, 256, 259, 261, 263, 264, 270) said that the testing and maintenance allowance for emergency engines in the proposed rule is not sufficient. Multiple commenters (218, 223, 228, 240, 241, 242, 250, 253, 259, 261, 270) recommended revising the definition of emerge ncy engines to be consistent with 40 CFR part 63, subpart ZZZZ for stationary reciproca ting internal combusti on engines (RICE). Two commenters (256, 263) suggested followi ng the California Airborne Toxic Control Measure (ATCM), which allows, depending on PM emissions, the California air districts to approve up to 50 hours per year or more for emergency engine maintenance and testing. Engines emitting higher levels of PM are given less hours (up to 20) for maintenance and testing. Commenter 263 said that if the above request cannot be accommodated in the NSPS, an alternative would be to allow the Air Resources Board (ARB) stationary ATCM in California to meet the requirements of the NSPS. 2 One commenter (248) suggested adding “or documente d engine repair” to the end of the last sentence of §60.4211(e) of the proposed rule. One commenter (223) requested that the rule be changed to either match wording in 40 CFR part 63, subpart ZZZZ for stationary RICE or be revised as follows: “Emergency stationary internal combustion engines may be operated for the purpose of maintenance checks and readiness te sting, provided that the tests are recommended by the manufacturer, the vendor, engineering standards, or the insurance company associated with the engine . Maintenance checks and readiness testing

2 EPA contacted the commenter for clarification on this request and the CA ARB recommends that the NSPS state that if an engine meets th e California ATCM then it meets the NSPS.

38of such units is limited to 30 hours per year or to durations permitted through regulatory agency issued orders of approval.”

One commenter (224) recommended a minimu m of 8 hours per month or 96 hours per

year.

One commenter (225) noted that it runs its emergency generators approximately 70 hours each year to meet hospital code requirement s, which could double if troubleshooting is required. The commenter also said that it inte nds to off-load power to the grid to avoid real time pricing penalties and that it has run over 100 hours on each machine when committed to that task. This commenter encouraged EPA to either exempt hospitals, categorically from the restrictions, or appl y a reasonable allowance of combined total operations of all emergency generators per hospital facility to 2,000 hours per year.

Four commenters (234, 236, 251, 255) reco mmended that EPA specify 100 hours per year instead, as a maximum for maintena nce and readiness testing. Commenter 234

recommended as an alternative that delegated regulatory agen cies could more adequately determine facility specific limits to readin ess testing under the title V permit program or other State Implementation Plan (SIP) ba sed program. Commenter 236 recommended allowing hospitals to petition for an exem ption raising the limit beyond 100 hours as: a) a permanent exemption for the largest, most complex systems base d on a substantiated need for additional testing (submit design and operational data) and b) a one-time exemption to exceed 100 hours based on extraordinary circumstances such as initial

39testing and commissioning, extensive repair or expansion of existing system, extended time without normal utility power. Commente r 255 recommended as an alternative that regulatory agencies could es tablish site-specific limits for maintenance checks and readiness testing. Commenter 251 recommende d the last sentence of §60.4211(e) of the proposed rule be revised to read: “The re is no time limit on the use of emergency stationary ICE in emergency situations or during training for, or simulation of, such emergency situations.” One commenter (238) recommended 500 hours per year for the use of emergency engines. If EPA decides to keep a limita tion for maintenance and testing, the commenter

recommended that such activities be limited to 78 hours per year. One commenter (264) said that the operation of an emergency engine should be at the discretion of the owner or operator, based on the engine manufacturer’s recommendations and any applicable health and safety codes. The commenter believed this requirement is unnecessary because non-emergency engines will be allowed to operate without any hourly limitations. The commenter added th at utilities ask th e owners of standby generator sets to use those sets to lower the owner’s electrical requirements on the utility during the utilities peak usage times. The usage amounts to less than 100 hours per year on average, according to the commenter. This helps the utility to keep its costs down because the utility does not ha ve to build more generating capacity, and is a win-win situation for the owner, the ut ility and the general public. Th e commenter stated that the

30 hour limit will cause utilities to build more power plants.

40Response : As summarized in this document , EPA received several comments on the

issue of maintenance and testi ng of stationary emergency engines. EPA proposed to limit the time emergency engines spend during main tenance and testing to 30 hours per year,

based on information available at the time of proposal indicating th at 30 hours per year would be sufficient to address operation fo r such activities. For example, NFPA requirements stipulated 30 minutes per week (27 hours per year) for maintenance and testing purposes to ensure that the engine would respond properly in the event of an emergency. A survey conducted by the CA A RB indicated that emergency engines spend on average of about 30 hours per year for all operation. The proposed limit of 30 hours per year for maintenance and testing for st ationary emergency CI engines was also

consistent with the CA ATCM. Since th e proposal of the rule, CA increased the maintenance and testing limit based on new in formation it had received, which indicated that more frequent testing was required by cer tain healthcare regulator y bodies. Local air districts in CA are allowed to approve addi tional hours of operation for maintenance and testing beyond 30 hours per year, and the ATCM also includes a sliding scale based on the PM levels the engine emits, of up to 100 hours per year. Considering the extent to which commenters provided information indi cating that the proposed 30 hours per year allowance was not sufficient for most emergency engines, EPA has determined that it is appropriate to allow emergency engine s to operate 100 hours per year during maintenance and testing. It is crucial to allow owners and operators of emergency engines to sufficiently test and maintain th eir emergency engines to ensure the engines will respond properly and as expected during an emergency situation. The engines must respond without failure and wit hout lengthy periods of startu p and adequate testing and

41maintenance must therefore be performe d. Based on the comments received, EPA believes that 100 hours per year is a sufficien t amount to ensure re adiness of emergency engines in most cases. The final rule has been written to limit operation of emergency engines to 100 hours per year during mainte nance and testing operation. In addition, EPA believes that there may be cases where it is necessary for an owner or operator of emergency engines to operate their emer gency engines beyond 100 hours per year to ensure their engines will res pond as needed during an emerge ncy. Additionally, Federal, State or local safety standards may require maintenance and testing beyond 100 hours per year. Therefore, EPA has incorporated a provis ion into the final rule that allows anyone to petition the Administrator for approval to operate their emergency engines for more than 100 hours per year for maintenance and testing purposes. If a sufficient case is presented, the Administrator may approve such petitions for additional time to conduct maintenance checks and readiness testing to en sure that emergency engines can be used for their intended application during emergency situations. A petition is not required if an owner or operator can show that oper ation beyond 100 hours is required by regulation such as State or local requirements. EPA doe s not believe it is ge nerally appropriate to

allow unlimited hours for maintenance and te sting, or hours well in excess of 100 hours, as suggested by some commenters, given the substantial emissions that can occur from these engines during their operati on and the ability of owners and operators to meet their maintenance and testing needs under the final provisions. The California ARB presented in Table IV-1 of their Staff Report fr om 2003 that PM and NOx emissions from emergency standby engines in 2002 were 0.3 and 6.4 tons per day, respectively. The maintenance and testing allowance in the final rule would include training for and

42simulation of emergency situations and EP A believes the 100 hours per year would be sufficient to account for such operation. Do cumented engine repair would also be considered maintenance and testing and the change from 30 to 100 hours per year should provide enough hours to make necessary repairs. Finally, peak shaving is not considered emergency use and EPA has clarified this in the definition of emer gency engine in the final rule. EPA responds to the issue of peak shaving in section 17 of this document.

3.2 Comment : One commenter (228) said that th e 30 hour restriction does not make

allowance for the manufacturer-recommended break -in period for new engines. If EPA

retains a fixed hour limitation for mainte nance and testing, EPA should include an explicit, allowable number of hours for a manufacturer-recommended break-in period.

Response : Engine manufacturers have told EPA that they do not have engine break-in requirements after the engine is delivered to the customer site. This information is

included in the docket to the final rule making. The engines are shipped from the manufacturing facility ready for normal use, according to the manufacturers. Therefore, EPA does not feel that it is necessary to in clude an allowance for a break-in period for engine owners and operators. Additionally, th e final rule provides 100 hours of operation per year for maintenance and testing of emer gency engines, instead of the proposed 30 hours. Owners and operators of emergency en gines could use the 100 hours per year that is designated for testing and maintenance for engine break-in, if necessary.

433.3 Comment : One commenter (238) stated that pursuant to §60.4211(e) of the proposed rule, emergency engines would be allowed to run an unlimited amount of time during an emergency. Without an annual limit of ope ration, the potential emissions of these engines must be calculated over an entire year (8,760 hours). This may result in an owner/operator of emergency engines being requ ired to install cost ly controls (which may not work based on the operating paramete rs of emergency engines) in order to comply with New Source Review regulations.

Response : EPA does not believe it is appropriate to limit the operation of emergency engines during emergencies. The operation of emergency engines during emergency situations varies widely and it is impossible to determine a one-size-fits-all limitation on the operation during emergencies. The operation of emergency engines is crucial to be able to support equipment needed during em ergencies, which could potentially be lifethreatening in cases of fire, flood, or power outages at hea lthcare facilities, and it is inappropriate to restrict the hours emer gency engines can spend supporting such equipment. The only operation of emergenc y engines that EPA is restricting is the operation during maintenance and testing, wh ich is limited to 100 hours per year.

3.4 Comment : One commenter (246) requested an exemption from the 30 hour operating limitation for emergency engines for nuclear power plants. The commenter suggests the following language: This regulation does not ap ply to engines under the regulation of the Nuclear Regulatory Commission (NRC), as long as the engines are run only to satisfy the NRC requirements. The commenter said that 1) For public safety reasons upon loss of

44power, the NRC requires these emergency en gines to be running and the generators loaded within a very few seconds. 2) All bu ildings and equipment associated with safety operation require design and construction to withstand se ismic events. (Reference: Appendix A of 10 CFR 50). 3) Engines with th e role of public safety require a prudent approach to changes (References: Appe ndix B of 10 CFR 50 Criterion III Design

Control and Criterion XI Test Control; NRC Regulatory Guide 1.9, Rev 3). Changes to the operating characteristics of the engine are not allowed. For other changes the normal methodology is to verify through testing of si milar equipment that hp ratings, exhaust backpressure and other important paramete rs are negligibly affected prior to implementing a change. Additionally, thes e engines have passed a rigorous NRC qualification process. Due to the age and vari ety of engines in the nuclear industry, test run data from similar engines is not necessarily available in these size engines, e.g., 6,000 hp. This coupled with the above make verifi cation of emission compliance difficult. 4) Engines with the role of public safety are r un only for mandated reli ability testing. These engines have minimum required maintenance op eration schedules that total more than 30 hours per year. The NRC mandated engine r un hours also increase dramatically if surveillance test failures occur, which require an increased frequency of retesting. These requirements suggest that exemption from the hour limitation is the best alternative.

Response : EPA addressed the issue of maintenan ce and testing in response to comment 3.1. As stated in response to that comme nt, owners and operators can operate their emergency engines for maintenance and test ing purposes up to 100 hours per year. EPA believes that 100 hours per year is a suffici ent amount to address the majority of

45emergency engines; however, owners may pe tition the Administrator for approval of additional hours, if necessary. Owners and operators may operate more than 100 hours per year without a petition, if required by Fede ral, State or local law or regulation to maintain and test their emergency engines more than 100 hours per year. EPA believes these provisions satisfy the commenter’s concerns.

4.0 Fuel Requirements

4.1 General

4.1.1 Comment : One commenter (228) expressed th at the proposed fuel requirements would be burdensome to some facilities that store and use large inventories of diesel fuel. To comply with the proposed fuel requireme nts, an owner/operator of stationary CI engines with large fuel inve ntories may have to dilute/blend existing diesel fuel inventories with fuel that is virtually su lfur-free prior to each compliance date in §60.4207 of the proposed rule, and sample/analyze the blended fuel for sulfur content, and cetane index or aromatic content to document compliance with the fuel content requirements. Sources with large fuel inve ntories may require d ilution quantities that exceed the existing storage tank capacities, and diluting/blending would be an expensive task. Diluting/blending fuel to meet these requirements would require the procurement of

diesel fuel that has a sulfur content and cet ane index or aromatic content that would be much more stringent than the specified fuel su lfur content standards. As an alternative, owners/operators would have to deplete existi ng diesel fuel inventor ies completely prior to each compliance date and then purchase fu el that meets the requirements of 40 CFR

46§80.510(a) and (b) for just-in-time fuel delive ry prior to each compliance date. This

alternative is not reasonable for owners/operators that operate 24 hours a day. Also, depleting inventories to zero potentially would cause owne rs/operators to have to clean/remove tank bottoms to prev ent fouling of fuel lines and equipment, and to have to dispose of off-specification diesel fuel, producing additional cost s. The commenter requested that EPA include a grandfather clau se that would allow owners/operators to continue to use up existing fu el inventories after Octobe r 1, 2007, and October 1, 2010. Alternatively, EPA could revise §60.4207(a) and (b) of the proposed rule by replacing the word “use” with “purchase.”

Response : EPA believes it is providing suffici ent time for owners and operators to switch to using lower sulfur fuel. Subs tantial amounts of fuel meeting the fuel requirements will be available in the years and months prior to implementation of the fuel requirements. However, EPA understands that there may be cases where sources may be unable to use up existing non-compliant fuel inventories prior to the fuel compliance

dates of the rule. EPA does not think it would be appropria te to include an open-ended provision allowing owners and operators to use up existing non-compliant fuel inventories after October 1, 2007 and Octobe r 1, 2010. Also, EPA does not believe it would be appropriate to use the word “purch ase” instead of “use” in §60.4207 of the rule. A more reasonable provision, which takes into account that there may be varying volumes of existing fuels from site to site , would be for the owne rs and operators to petition the Administrator for additional time beyond the schedul e set in the final rule to use up existing non-compliant fuels. EPA be lieves that a case-by-case approach to

47dealing with existing fuel inventories is more appropriate and will incorporate the uniqueness of each source’s fuel inventory s ituation. EPA has incorporated a provision

into the final rule that allows owners and operators that have st ationary CI engines subject to the rule to peti tion the Administrator for additional time to use up existing noncompliant fuel inventories. If approved, the petition is valid for a period of up to 6 months. If additional time is needed beyond that, the owner or operator would have to submit another petition to the Administrato r. Also, EPA does not believe such a provision should be included for engines built after 2011 as these stationary CI engines will require the use of ULSD in order to operate properly. Therefore, the final rule includes the provision to petiti on the Administrator to use up existing non-compliant fuel for a period of 6 months only for pr e-2011 MY stationary CI engines.

4.1.2 Comment : One commenter (238) concurred w ith EPA’s decision to require lower sulfur diesel fuel. However, the comm enter believed ULSD will be available in sufficient quantities by fall 2006 to supply stationary engines.

Response : As discussed in EPA’s nonroad diesel Tier 4 rule, EPA believes there is a need for a period of lead time prior to impl ementation of the 15 ppm sulfur requirement. Given the significant actions that are required for refiners to meet the 15 ppm standard, it would not be possible to require 15 ppm fuel in the same time frame as the 500 ppm sulfur requirement. While 15 ppm sulfur dies el fuel will be available by 2006, due to the requirements applicable to highway diesel fuel, EPA ca nnot be certain enough 15 ppm

fuel will be available in all locations to accommodate the additional needs of stationary

48engines. Therefore, we belie ve that phasing the 15 ppm require ment in at the same time as it becomes applicable to the nonroad ma rket will allow for a more feasible and

reasonable transition for stati onary engines.

4.1.3 Comment : One commenter (265) supported a requirement of meeting a fuel sulfur content limit of 0.0015 percent by weight as a practical and efficient way to minimize sulfur dioxide (SO 2 ) emissions and allow th e use of catalyzed dies el particulate filters (CDPF) and NOx adsorbers to achieve ma ximum levels of emission reduction.

Response : No response is needed.

4.1.4 Comment : One commenter (238) stated that §60.4207(b) of the proposed rule cites 40 CFR 80.510(b), which specifies 15 parts pe r million (ppm) sulfur content for nonroad diesel fuel, and 500 ppm sulfur fuel content for locomotive a nd marine diesel fuel. The sulfur limit that would apply for stationary engines is unclear, although it is assumed that EPA intends to require 15 ppm sulfur fuel. The commenter suggested that EPA either change the reference to 40 CFR 80.510(c), or write §60.4207(b) of the proposed rule to

read: “...must use diesel fuel that meet s the requirements of 40 CFR 80.510(b) for

nonroad diesel fuel.”

Response : EPA acknowledges that the sulfur limit that would apply to stationary engines was unclear in the proposal. It would not be accurate to cite to th e fuel requirements in 40 CFR 80.510(c). Those fuel requirements begin on June 1, 2012 and are inconsistent

49with EPA’s intent for fuel requirements for sta tionary CI engines. It is EPA’s intent to require 15 ppm sulfur fuel starting October 1, 2010. EPA has clarified this and has

included “...for nonroad diesel fuel.” in §60.4207(b) of the final rule.

4.2 Alaska

4.2.1 Comment : One commenter (233) noted that EP A’s past mobile source rulemakings have provided the necessary flexibility for Al aska to transition to ULSD, in recognition of Alaska’s unique fuel distribution circumstances. Th e proposed rule may significantly and disproportionately increase the cost of power in rural Alaska and possibly increase home heating fuel cost. The commenter recommended eliminating the requirement to use 500 ppm sulfur fuel between Octobe r 2007 and October 2010 in rural Alaska. Phasing fuel in different stages, as propose d, would create an unnecessary logistical and financial hardship for rural Alaska communities for a relatively small environmental gain. A one step transition to ULSD in 2010 will re duce adverse effects to Alaska and provide

several benefits.

The commenter recommended that EPA perform Alaska specific cost benefit analyses and participate in a rural diesel health assessment. The substantive air quality benefits of the proposed rule will not be realized for decad es since it relies on diesel engine turnover and newer engines being equipped with post-co mbustion control. Due to uncertain cost and health concerns, Alaska cannot support the proposed rule without additional Alaska specific cost benefit analyses. The comm enter recommended specific costs and health

50benefits analyses for rural Alaska. Th e commenter believed that two types of assessments will be necessary for rural communities to make decisions on fuel choices, storage tanks and marine transport of those fu els. These are: 1) an economic assessment of the fuel cost differential for ULSD as delivered to rural communities including amortized infrastructure costs, and 2) whether emissions from existing technology engines and fuels cause significant he alth risks for rural residents.

Two commenters (234, 255) expres sed that the fuel requiremen ts in the proposed rule are incompatible with the requirements of 40 CF R 69.51(a) and (b) for Alaska sources. The final rule must be written to incorporate the exemptions in 40 CFR 69.51, or separate rulemaking should be undertaken that includes the Alaska exemption th at takes effect at the time subpart IIII becomes final.

Two commenters (234, 255) said that it is common practice for owners/operators in remote locations of Alaska to economically dispose of on-specification used oil by mixing it with diesel fuel and burning it in CI engines. In some cases, it is the only way to dispose of used oil. The fuel requirements and PM limitations in §§60.4201 and 60.4202 of the proposed rule will eliminate the ab ility of an owner/operator to burn used oil/diesel blends. There is no economic or environmentally safe alternative to blending/burning in most remote locations in Alaska.

Two commenters (234, 255) stat ed that the standards need to be revised to allow manufacturers to provide engines that can ope rate intermittently on used oil/diesel blends

51without meeting stringent PM or fuel sulfur standards. Alternatively, delegated regulatory agencies could more adequate ly determine facility specific limits for

combustion of used oil/diesel blends under the title V program or other SIP based

program.

Response : EPA issued a proposal in October of 2005 (70 FR 59690), which proposed to delay the nonroad fuel requirements to 2010 fo r rural areas of Alaska. That proposal applies to stationary engines covered by th e NSPS as well. The proposal would delay low sulfur fuel requirements for new stationa ry engines in areas of Alaska not supported by the Federal Aid Highway System until De cember 1, 2010, but requires 2011 and later MY engines located in rural areas of Alaska to comply with the 15 ppm sulfur requirements. EPA believes this addresses the commenters’ concerns regarding timing and phasing of fuel requirements. EPA believes that it is most appropriate to finalize the delay of the stationary engine fuel requirements for rural areas of Alaska in the same rule as the finalization of the nonroad fuel delay, be cause it is appropriate that fuel issues for rural Alaska be handled in a single rule wh ere all related issues can be reviewed and

resolved. EPA has included a section in this final rule that refers parties to 40 CFR part 69 to find out the fuel requirements for area s of Alaska not supported by the Federal Aid Highway System until December 1, 2010.

Commenter 233 appears to say that further measures, like retrofits that cannot be compelled in this regulation, may be appropria te. The commenter is free to pursue such actions if it believes it is appropriate. The co mmenter also states that the costs for rural

52Alaskans will be unique, because they rely to a greater extent on such engines. While this is true, the health benefits for rural Al askans can be much greater than the costs, especially given the usage of these engines. The commenter does not provide evidence

that the costs and benefits of this in rural Al aska are so different from the cost and benefit analyses performed for this rule, in particular , the comparisons of benefits to costs, are inapplicable to such engines.

In response to commenter 233’s recommendation th at EPA should assist Alaska in a rural diesel health assessment, such help, if av ailable within EPA’s own budget constraints, may be helpful and appropriate, but such assi stance is not part of this rulemaking. The commenter has noted that most rural villag es use one community tank for all fuel, and about 5 percent of the fuel is for mobile sources and another 25-45 percent for power production, with the rest for heating fuel. Th e issue of how to handl e the introduction of ULSD fuel, either having to purchase new storage facilities, or to purchase only low sulfur diesel fuel, or take steps to reduce th e need for ULSD fuel for as long as possible (through use of older engines) is one that villages will need to d eal with as a result of the nonroad engine Tier 4 rule as well as this rule. Agai n, EPA recognizes that rural Alaskans have some unique costs associated with this fuel change, and EPA is taking steps to reduce them, but the emission reducti ons from this rule can bring substantial

health benefits for these communities that ou tweigh the costs of the program. To address Alaska’s concerns, the final regulations includ e language that allows Alaska to submit for EPA approval through rulemaking process, by no later than 18 months after publication of the final rule, an alternative plan for implementing the requirements of this regulation

53for public-sector electrical utilities located in rural areas of Alaska not accessible by the Federal Aid Highway System. The alternative plan must be based on the requirements of section 111 of the Clean Air Act including any increased risks to hum an health and the

environment and must also be based on the uni que circumstances related to remote power generation, climatic conditions, and se rious economic impacts resulting from implementation of 40 CFR Part 60 Subpart IIII.

Regarding the comment related to mixing used oil with diesel fuel and burning it in CI engines, EPA disagrees. Engines that are bui lt after 2011 cannot use an y diesel fuel other than 15 ppm diesel fuel. Engines built after 2011 must use 15 ppm sulf ur diesel fuel or the engine can be severely damaged. Used oil cannot be used in these engines and will have to be disposed of in other ways, perh aps by being burned for heat. EPA believes it would be reasonable to allow pr e-2011 MY engines located in remote areas of Alaska to burn such fuels on a case-by-case basis. The final regulation includes a provision in §60.4207 that allows owners and operators of pre-2011 MY engines located in areas of Alaska not accessible by the Fe deral Aid Highway System to petition the Administrator for approval to use fuels mixed with used l ubricating oils. The petition must include

information that shows that the owner has no ot her place to use the oil, and if the petition is approved, it is valid for a period of up to 6 months.

In response to the comment requesting revi sed emission standards, EPA disagrees.

Emission standards are set at certification so no new standards are required. However, owners and operators must operate the engine according to the manufacturer’s

54specifications. This may, or may not allow (and for post-2011 engines, certainly will not allow) blending with used oil. For pre- 2011 MY engines located in remote areas of Alaska, the final regulation has been written to allow some amount of relief from the sulfur specifications if the owner or operat or can show that there is no way to avoid blending with used oil, as discus sed in the previous paragraph.

4.3 Engines with a Displacement of ≥ 30 Liters per Cylinder

4.3.1 Comment : One commenter (235) stated that no operating experience currently exists for engines with a disp lacement of greater than or equal to 30 l/cyl with 15 ppm sulfur fuel, and therefore, an alternative should be worked out. The use of ULSD may have impacts on safety, reliability and durability of the stationary engine. At the current stage of technology, engine manufacturers wi ll not be able to guarantee an engine operating exclusively on ULSD. According to the European Union (EU) Directive 1999/32/EC, the maximum sulfur content of h eavy fuel oil is a maximum of 1 weight percent (10,000 ppm) from January 1, 2003, a nd in gas oil a maximum of 0.1 weight percent (1,000 ppm) from January 1, 2008. Thes e fuels can be used in stationary CI engine plants without installed flue-gas desulfurization. A ccording to the EU 2001/80/EC Directive, a maximum of 0.5 wei ght percent sulfur (850 milligrams per Normal (273.15 °Kelvin, 101.3 kilo Pascal (kPa)) cubic meters (mg/Nm 3 ) SO 2 at 3 percent oxygen (O 2 ) and 280 mg/ Nm 3 SO 2 at 15 percent O 2 ) fuel oil can be used in 50 to 100 megawatt (MW) boiler plants. Large CI engines are designed to operate on heavy fuel oil and the use of ultra clean light fuel oils (with different density, viscosity, etc.,

55properties) may cause operation problems. The commenter requested that for large engines the requirement should be equiva lent to 500 ppm after 2010 on the U.S. mainland. The commenter also stated it was reasonable for EPA to exempt Guam,

American Samoa and the Commonwealth of the Northern Mariana Islands from fuel

limits.

Another commenter (240) expressed that addi tional time may be necessary to phase in the use of ULSD with respect to new engines with a displacement of 30 l/cyl or greater.

Response : EPA requested comments on whether ow ners and operators of stationary CI engines with a displacement of greater than or equal to 30 l/cyl should be required to use ULSD fuel. There is no information regarding the effect of burning 15 ppm sulfur fuel in stationary CI engines with a displacement of greater than or equal to 30 l/cyl and operators of these engines have expre ssed concerns with burning such fuel. Manufacturers of engines with high displacemen t have told EPA that there is a large variety of fuels used in these engines and th at the fuel used can contain a high sulfur content. The fuels used in large displacemen t engines are of a different grade than the fuels used in nonroad engines. Information EP A has received indicates that engines with a displacement of greater than or equal to 30 l/cyl are often designed to operate on residual fuels containing up to 5 percent sulfur, but that thes e engines can also operate on

fuels with lower fuel content. Further in formation on this subject can be found in the docket (EPA-HQ-OAR-2005-0029-0146). EPA belie ves it would be inappropriate to require owners and operators of these engines to use ULSD as the impacts of using such

56fuel are unknown. However, EPA does believe it is appropriate to require these engines to utilize fuel containing 500 ppm sulfur or less, consistent with the commenter’s

statement. The final rule has been written to require owners and operators of stationary CI engines with a displacement of greater than or equal to 30 l/cyl to use 500 ppm sulfur fuel starting October 1, 2007. Owners and opera tors of stationary CI engines with a displacement of greater than or equal to 30 l/cyl are not required to use 15 ppm sulfur fuel, but must use 500 ppm fuel from October 1, 2007, and beyond.

4.4 ULSD and Older Engines

4.4.1 Comment : One commenter (240) said that the requirement that owners/operators of all stationary IC engines must use ULSD as of October 1, 2007 3 , could cause problems for certain engine installations that were not designed to operate on ULSD (e.g., older engines with high injection pressures). This suggests that retroac tive application of a ULSD requirement in this context needs further investigation.

Another commenter (264) believed the requirement to use ULSD and low sulfur diesel (LSD) will cause considerable hardship for ow ners/operators of stationary engines. Standby generator sets have a useful life of over 20 years due to their low hours of usage per year. The fuel systems of many engines built in the year 2000 and before have fuel systems that will seize up if used with low sulf ur fuels. The cost to replace these engines will be astronomical compared to their small amount of emissions per year. The commenter urged EPA not to adopt a fuel sulfur requirement for existing engines.

3 EPA contacted the commenter and clar ified that the comme nter meant 2010.

57Response : The fuel requirements in the rule apply only to owners and operators of stationary CI engines subject to the rule. The fuel requir ements do not apply to existing engines, unless the engines are modified or reconstructed after the date of proposal, which would make these engines subject to th e rule. EPA believes that, with regard to those rare internal combustion engines that are modified or reconstructed, the level of change needed to become subject to those provisions is such that any engine becoming subject to those provisions will likely be changed to a degree that refurbishing the engine to ensure ability to use ULSD will not cause significant problems. EPA has made it clear in the final rule that the fuel requiremen ts of §60.4207 apply only to those engines that are covered by the rule, as sp ecified in the applicability section of the rule §60.4200.

4.5 Add-on Controls

4.5.1 Comment : One commenter (244) stated that le ss than 15 ppm diesel is absolutely essential for meeting EPA’s proposed PM sta ndards for stationary engines rated from 25 to above 750 hp. Sulfur affects CDPF pe rformance by inhibiting the performance of catalytic materials upstream of or on the filter. This phenomenon not only adversely affects the ability to reduce emissions, but al so adversely impacts the capability of these filters to regenerate and there is a direct trad e-off between sulfur levels in the fuel and the ability to achieve regeneration. Sulfur also co mpetes with chemical reactions intended to reduce pollutant emissions and creates PM through catalytic sulfate formation. The availability of less than 15 ppm sulfur fuel will enable these filters to be designed for

58improved PM filter regeneration and emission control performance, as well as to minimize any increase in sulfate emissions. Dies el fuel with a sulfur content of less than 15 ppm is absolutely essential to commercializing NOx adsorber systems that can function effectively. At higher sulfur levels, a NOx adsorber quickly becomes ineffective

as the sulfur attaches to the sites meant to “t rap” the NOx. The sulfur remains attached to these sites until high temperature, rich condi tions, which are not characteristic to normal diesel engine operation, are met. Als o, while a sulfur regeneration mode or desulfurization cycle will need to be employed in any case, the frequency of

desulfurization must be minimized to a void substantial fuel economy penalties and perhaps a degradation of the NOx adsorber perf ormance that, in turn, will require an even more frequent desulfurization. As the sulfur level increases, the frequency, as well as the severity, of regenerations needed increases.

The commenter added that the effectiveness of selective catalytic reduction (SCR) and lean NOx catalyst technology would greatly benefit from the use of less than 15 ppm sulfur fuel in terms of improved emission control performance and minimization of the sulfate formation when precious metals are used. Although diesel oxidation catalysts will function effectively with less than 500 ppm fuel, the availability of 15 ppm will improve overall PM control efficiency by reducing the sulfate production and will enable the utilization of more active catalyst formulati ons that could provide greater reductions in toxic hydrocarbons (HC) and the soluble organic fraction of the PM emissions, according to the commenter. The commenter suppor ted the proposal of extending the 15 ppm

59sulfur limit to diesel fuel sold for use by all stationary diesel engi nes, including engines with a displacement of 30 l/cyl or greater.

Response : EPA agrees with the commenter with regard to engines with displacement below 30 l/cyl. However, as discussed above , EPA does not have enough data regarding the use of 15 ppm sulfur fuel in engines above 30 l/cyl to require 15 ppm sulfur fuel for such engines. The commenter provided no da ta on this issue supporting its request to extend the 15 ppm requirement to these engines.

5.0 Test Methods

5.1 Comment : One commenter (240) stated that th e field test methods to be utilized under the NSPS also will need to be fully aligned with and equivalent to the nonroad engine certificat ion test methods.

Response : EPA believes the test methods as propos ed are consistent w ith those required for nonroad diesel engines. EPA references the nonroad test regulations in the NSPS regulations.

5.2 Comment : Two commenters (259, 261) expresse d support for inclusion of EPA Method 19 and EPA Method 7E in the proposed rule, but other test methods should also be included and allowed, such as AS TM Method D6522-00 and extractive Fourier Transform Infrared Spectroscopy (FTIR). Extractive FTIR test methods and portable analyzers have proven effective for measur ing emissions from combustion equipment,

60and associated test methods have been in cluded in other recent EPA regulations, e.g., proposed subpart KKKK for stationary combustion turbines and 40 CFR part 63, subpart ZZZZ for stationary RICE. EPA should allow th e use of FTIR and portable analyzer test methods in the CI NSPS. For portable analyzers, ASTM Method D6522-00 has been developed based on validation testing conducte d by GRI and an independent peer review and approval through ASTM. The method has been accepted by EPA for other standards such as 40 CFR part 63, subpart ZZZZ for stationary RICE and the stationary combustion turbines NSPS proposal (40 CFR part 60, subpa rt KKKK). Two test methods have been commonly applied for FTIR testing and have also been included in other regulations for measurement of exhaust species from com bustion equipment. The final rule should

include both FTIR methods: EP A Method 320 and ASTM Method D6348.

Response : EPA has retained EPA Methods 10 and 7E in the final rule. EPA agrees with the commenter that FTIR is appropriate and has included FTIR as an acceptable option in

the final rule. The final rule has been written to include EPA Method 320 and ASTM

Method D6348-03. EPA does not believe that it is appropriate to include ASTM D6522-

00 in the final rule. This method is a test method for portable analyzers for natural gas fired engines and may not be appropriate for di esel fired stationary engines. EPA has not

included ASTM D6522-00 as an alternative to Method 10 or Method 7e for CO or NOx

measurement in the final rule because ASTM does not represent this method for sources other than natural gas-fired combustion sour ces (refer to Section 1.1.1 of ASTM D6522- 00 and title of same).

615.3 Comment : One commenter (235) said that in Europe, the PM measurement method used is in principal similar to EPA Met hod 17. Comparison has shown that different methods have given different results, e.g., when comparing EPA Method 17 and EPA Method 5, it has been noted that EPA Method 5 usually gives much higher measurement results. In a CIMAC (International C ouncil on Combustion Engines) recommendation 4

, it is recommended to use PM measurement me thods principally similar to EPA Method 17 instead of a method where exhaust gas has to be cooled dramatically leading to a nonreproducible sampling.

Response : EPA has noted the commenter’s con cerns. However, EPA Method 5 (versus EPA Method 17) is thought to be the only a ppropriate test method since it requires the filter temperature to be held at a near constant temperature ( 120 ± 14 °C ( 248 ± 25 o F ) ), and therefore results are more reproducib le. EPA Method 17 does not control filter temperature so there is a good chance of extremely variable results, depending on the exhaust temperature. Therefore EPA does not believe it is appropriate to allow EPA Method 17, but feels that EPA Method 5 is the appropriate test method to use to measure

the concentration of PM from the stationary CI engine exhaust.

6.0 Flexibility/ABT

6.1 Comment : One commenter (238) made the poi nt that the average, banking, and trading (ABT) provisions of the proposed NSPS are not co mpatible with the NY DEC’s

4 CIMAC Recommendation – Standards and Methods for sampling and Analysing Emission Components in Non-automotive Diesel and Gas Engine Exhaust Gases – Marine and Land Based Power Plant Sources. CIMAC Working Group on Exhaust Emissions. February 2005. The document can be ordered from: http://www.cimac.com/services/I ndex1-techpaperdatabase.htm

.

62regulatory approach for stationa ry sources in which the owne r/operator is responsible for complying with all applicable emission limits.

Response : As stated in more deta ils in the preamble to the proposed rule, EPA believes the proposed ABT provisions are appropriate for this regulation. The ABT provisions are important elements in establishing a manuf acturer-based certification program that will be feasible for stationary CI engines. Engine manufacturers are familiar with ABT provisions from the nonroad engine program , and many of those same manufacturers produce stationary engines affected by this rule. As stated in the preamble to the proposed rule, the proposed ABT provisions are essential elements in EPA’s determination that the proposed standards reflect BDT. There are many benefits and advantages of including an ABT program in th e rule, as described in the preamble to the proposed rule. The ABT program also provi des engine manufactur ers flexibility in producing certified engines that meet the standa rds of this rule. For these reasons, and as explained in further details in the preamble to the proposed rule, EPA believes it is justified to include ABT provisions in the final rule.

6.2 Comment : One commenter (240) strongly agr eed that the inclusion of a fully integrated ABT program (as well as flexibility provisions) is critically important to the feasibility of the proposed NSPS. The commen ter added that in addi tion to incorporating the ABT program as currently applies in th e nonroad rule, the final rule needs to incorporate and allow for the fully-integrated application of flexibility provisions allowed under the nonroad rule (see 40 CFR §89.102( d); 40 CFR §1039.625). Without this

63necessary flexibility, cost-effective integrati on of stationary engines and equipment will be hampered (if not preclude d), and significant product shorta ges and dislocations could result (given the growing number of regulatory demands for current-Tier nonroad engines). The NSPS provisions need to adopt and incorporate by reference all of the relevant nonroad ABT provisions, including the ABT calculation provisions (see 40 CFR §§1039.701-1039.740).

Response : As proposed, EPA is including the ABT program from the nonroad road provisions into the final rule. EPA does not be lieve it is necessary to cite the specific nonroad ABT provisions in the final rule; it is clear in the regulation that EPA is incorporating them. Regarding equipment ma nufacturer flexibility, the provisions of 1039.625 (and 89.102) are designed to help equipm ent manufacturers, who are not being regulated in this rule. Equi pment manufacturers have flexibil ity under this rule to take actions not permitted under the nonroad regulations because they are not directly regulated by this rule. In addition, engine manufacturers have not shown that the considerations for integrating engines into ne w equipment that motivat ed these provisions are applicable to stationary applications.

6.3 Comment : Two commenters (259, 261) were of the opinion that EPA must ensure that flexible options such as emissions averag ing are retained in the rule for all categories of engines, e.g., large units that are subj ect to owner/operator compliance requirements are not afforded the same flexibility. EPA ha s previously considered flexible approaches for engines under the NOx SIP Call Phase II Rule. The approach for the Phase II Rule is

64based upon achieving a tonnage reduction target rather than engine -specific technology performance. Commenter 259 believed that a variety of flexible options are available that are appropriate for inclusion in an N SPS, e.g., a compliance plan developed by the operator could be used, as recommended in the Phase II guidance.

The commenter recommended that EPA retain the flexible approaches available for

certification and also include a pproaches such as emissions averaging for all engines that will be affected by the NSPS.

Response : EPA is required to set emission standa rds that are based on BDT. For engines that are required to be certified, BDT incl udes the ABT program, which is necessary and crucial to the success of the certification progr am. It would not be appropriate to include emissions averaging for engines not included in a certification progr am by an engine

manufacturer and it is outs ide EPA’s authority under this action to incorporate such flexibility. For owners and opera tors, the rule is flexible in that owners and operators that do not purchase certified engines have severa l ways of demonstra ting compliance with the rule, as specified in §60.4211. In addition, owners and operators who conduct performance tests to demonstrate compliance with the emission standards have to show

that exhaust emissions from their stationa ry CI engines meet not-to-exceed (NTE) standards, as opposed to the certification emission standard s. The NTE standards which owners and operators have to co mply with if they decide to test their engines are higher than the certification standards, which provi des owners and operators flexibility in meeting the standards in the field. Also, EPA is allowing owners and operators in conjunction with the engine manufacturer to develop site-specific operating and

65maintenance procedures that must be follo wed at all times, thereby incorporating a certain level of flexibility in the continuous compliance requirements for owners and

operators.

667.0 Compliance

7.1 Following Manufacturer’s Instructions

7.1.1 Comment : One commenter (261) expressed c oncern that the requirement that owners/operators must follow manufacturer operating and maintenance (O&M) provisions is onerous. Operators of engines often have existing O&M practices that may differ from the vendor recommendations, but are designed to address the specific challenges and rigor of the applicati on. The commenter recommended that owners/operators be allowed to follow an O&M procedure based upon manufacturer recommendations and/or ope rator defined procedures.

One commenter (253) stated that the proposed rule requires owners/ operators to operate their engines in accordance with the engine ma nufacturer’s written instructions over the entire life of the engine and operate and ma intain the stationary CI engine and control device according to these instructions. These provisions do not provide facilities any flexibility. Flexibility is critical to many facilities, especially those with non-standard operations that may not be addressed by the manufacturer’s written instructions. In addition, modified and reconstructed engines will require modifications to the original manufacturer instructions. However, as th e facility modifying or reconstructing the engines would not be considered a manuf acturer as defined under §60.4216 of the proposed NSPS, modifications to the instructio ns would not be allowe d. Modifications to

these instructions would be n ecessary to ensure that the proposed CI ICE emission limits continue to be met. To provide flexibility for facilities and ensure that the emission limits

67of the rule are met, the commenter recommended that EPA replace §§60.4206 and 60.4211(a) of the proposed rule with the following provision from 40 CFR part 63, subpart ZZZZ for stationary RICE: “If you mu st comply with emission limitations and operating limitations, you must operate and main tain your stationary RICE, including air pollution control and monitoring equipment, in a manner consistent with good air pollution control practices for minimizing emissions at all times, including during startup, shutdown, and malfunction.”

One commenter (258) stated that the language that owners/operato rs must operate and maintain their stationary CI ICE according to the manufacturer’s “w ritten instructions” over the entire life of the engine can be va gue and confusing. The commenter asked what “written instructions” EPA is referring to. The commenter said that manufacturers often develop stock manuals that can be very conser vative. Others may develop, at the request of the purchaser, site-specifi c operation and maintenance instructions. The commenter asked which set of instructions would appl y. The facility, in consultation with the manufacturer, might develop its own O&M inst ructions. This happens often in Alaska due to the extreme climatologi cal conditions and the remotene ss of many facilities. Since the instructions are the result of a joint e ffort, the commenter asked if these could be

considered manufacturer’s writte n instructions with which a f acility can elect to comply. The commenter suggested modifying the rule (perhaps by defining “manufacturer’s written instructions”) permitting owners/operators the flexibility with manufacturer’s

written instructions as discussed above. There are also cases where manufacturers may fold, relocate, or otherwise change in a ma nner that makes updating of their instructions

68excessively difficult though such updating may be absolutely necessary due to conditions. A facility, in this case, may have to unilaterally modify the instructions and this would leave them vulnerable to charges of viol ating the rule. The commenter suggested including language that allows owners/operators to change instructions so long as

consultation with EPA occurs.

One commenter (259) requested that EP A revise the provisions that require owners/operators to follow manufacturer O&M procedures. Engine operators should be allowed to use O&M practices that have been developed by the owners/operators to address the specific challenges, rigor, and accessibility of their application. The commenter cited two State permits (in Alaska an d Colorado) that allow this for stationary engines. For example, the following exampl e text is included within Alaska title V permits:

Good Air Pollution Control Practice The Permittee shall do the following for Emission Unit ID(s) [insert ID number]:

a. perform regular maintenance consideri ng the manufacturer's or the operator's maintenance procedures;

b. keep records of any maintenance that would have a signi ficant effect on emissions; the records may be kept in electronic format;

c. keep a copy of either the manufacturer's or the operator's maintenance procedures.

In addition, text from a Colorado permit refe rences a maintenance plan and indicates:

69• These engines shall be operated and maintained in accordance with the manufacturer’s recommendations, Compa ny’s internal policies, and industry standards. Maintenance activities are ty pically performed based on the number of “fired hours” or as indicated by engine analysis results.

• Records of all maintenance and overhau ls performed on the engines will be

maintained. This example indicates that on-site inspecti on and analysis, i.e., on-site factors unknown to the vendor is integral to maintenance deci sions. Both of these examples provide the owner the necessary control over operational decisions that sh ould not reside solely with the manufacturer, while ensuring that prope r procedures are followed and significant

maintenance activities are documented.

Response : EPA disagrees that the requirement for owners and operators to follow the

manufacturer’s instruct ions is onerous. EPA believes the requirement is justified and appropriate, especially in the absence of a requirement to conduct performance testing. EPA does not believe that operating and main taining an engine and control device, according to established written instructi ons by the manufacturer, is a burdensome requirement. This requirement provides a reas onable level of assurance that the emission

standards continue to be met during engine operation in the field, in the absence of any emission limits applicable to the owner a nd operator. However, EPA recognizes that there may be instances where an owner or ope rator may tweak or alter the manufacturer’s typical guidelines, to address site-specific conditions. In su ch case, a site may have a different set of instructions to follow during operation and maintenance that vary from

70the original manufacturer r ecommendations. EPA believes it is acceptable to allow owners and operators to follow instructions that were developed to address needs not

covered in the manufacturer stock manual. However, the modified operation and

maintenance instructions must have been developed in conjunction with the engine manufacturer and both parties must have agreed to the modified set of written instructions. During the useful life of the engine, it is ultimately the engine manufacturer who is responsible for meeting the limits. Th erefore, it is extremely important that the procedures followed are supported by the engi ne manufacturer. EPA has specified in the final rule that owners and operators must opera te and maintain their stationary CI engines

in accordance with the manufacturer’s written instructions, or according to procedures developed by the owner or operator that are approved by the engine manufacturer.

7.1.2 Comment : One commenter (266) cited section III.E.3.a of the preamble to the proposed rule, which contains the proposed st andards for owners/operators of stationary CI engines with a displacemen t of less than 30 l/cyl. The commenter stated that the owners/operators are required to perform maintenance on the engines as recommended by the manufacturer, which should be sufficien t to ensure the emi ssion standards are met over the entire life of the engine. It should not be necessary for the owners/operators to

validate with additional testi ng the emission standards if the engine is maintained.

Response : The section that the commenter is referring to discusses the proposed standards for stationary CI e ngines with a displacement less than 30 l/cyl. The owners and operators of these engines are not require d to conduct testing in order to demonstrate

71compliance with the emission standards. Testing is one option for demonstrating compliance. However, other options are availa ble, such as purchasing a certified engine or keeping records of data from the engi ne manufacturer. Once the 2007 MY begins and all such engines are required to be certified by the manufact urer, there are no testing requirements for owners and operators.

7.1.3 Comment : One commenter (267) suggested that an engine manufacturer is best suited to make recommendations with respect to the maintenance of its product, and that additional maintenance requirements should not be imposed on those customers by EPA or any other agency. The ma nufacturer recommendations wo uld apply to the entire life of the engine, as drafted in the propo sal. It would be unnecessary for the owners/operators to validate those require ments with additional testing and emission standards, so long as the engine is maintain ed pursuant to the recommendations of the

manufacturer.

Response : EPA is not imposing additional maintenance requirements beyond those recommended by the engine manufacturer or those developed by the owner/operator in cooperation with the engine manufacturer.

727.2 Pre-2007 Model Year Engines and Engines that Conduct Performance Testing

7.2.1 Comment : One commenter (240) stated that all that should be necessary to demonstrate compliance for owners/operato rs of pre-2007 MY engines is that the manufacturer provide access to the original parent engine ce rtification data and related engine model listings on request. The comm enter stated that this issue needs to be resolved (perhaps through issuance of EPA guidance) well in advance of April 1, 2006, and prior to issuance of the final NSPS, si nce requirements pertaining to pre-2007 MY engines will take effect on April 1, 2006.

Response : In the proposed rule at §60.4211(b), seve ral options were provided for owners and operators of pre-2007 MY engines to demonstrate compliance with the emission standards. One of these options was to k eep records of engine manufacturer data indicating compliance with standards (§60.421 1(b)(3)). These provisions have been

retained in the final rule. EPA does not believ e it would be a signifi cant effort for owners and operators to maintain records of this information and does not agree with the

commenter that it is sufficient for the e ngine manufacturer to provide access to the information. Original parent engine certifi cation data would be acceptable information to show compliance, consistent with EPA’s regulations regarding engine families; however, the owner or operator must maintain a copy of this information in order to comply with the regulation.

737.2.2 Comment : One commenter (240) expressed that any potential initial performance testing of stationary CI e ngines to assess compliance w ith the nonroad not-to-exceed (NTE) standards (see §§60.4211(b)(3) 5 and 60.4212(b) of the pr oposed rule) should not be required until the NTE standards begin to take effect for nonroad engines under 40 CFR part 1039.

Response : EPA believes that it is appropriate to require that owners and operators of stationary CI ICE with a displacement of less than 30 l/cyl who conduct testing to demonstrate compliance be required to demonstrate compliance to NTE standards. The NTE standards are less stringent than the sta ndards that apply to certified engines, to allow for the fact that testing may occur ove r different use conditions than the specific conditions required for certification testing. Engines subject to 40 CFR parts 89 and 94, in addition to pre-2007 MY engines, must meet NTE requirements if the owner or operator conducts testing. Alternatively, thes e engines may be tested using the provisions specified for engines with a displacement of greater than or equal to 30 l/cyl. This change is reflected in the final rule. The final rule does not require any owner/operator testing for certified engines, including, fo r engines with displa cement of less than 30 l/cyl, all model year 2007 and later engines and those pre-2007 model year engines that are certified. For those engines that are not certified, no other testing is required for such engines, so performance testing is justif ied. In the proposed §60.4212, EPA intended to include engines subject to 40 CFR part 94 and this correction has been made to the final rule. Engines subject to 40 CFR part 1039 must meet the NTE requirements of that part. EPA has clarified in §60.4212(b) of the final ru le that the requiremen ts of that section

5 EPA contacted the commenter an d clarified that the commenter meant §60.4211(b)(5) and not (3).

74will start when NTE requirements take eff ect for nonroad diesel engines under 40 CFR part 1039.

7.2.3 Comment : One commenter (258) asked that EPA clarify the applicability of §60.4214(a) through (c) of the proposed rule. As written, it appears the paragraphs can be construed to cover engines manufactur ed prior to April 1, 2006. The commenter suggested that one way to rectif y this is to modify the defi nition of stationary internal combustion engine to exclude those manufactured prior to April 1, 2006.

Response : Section 60.4212 of the pr oposed rule applies to owners and operators of stationary CI engines with a displacement of less than 30 l/cyl that are subject to this subpart that conduct performance tests to de monstrate compliance with the rule. Based on the applicability in §60.4200 of the propos ed rule, it is possible that engines manufactured prior to April 1, 2006 could be subject to the requirements in §60.4212, but only if the engines commence modification or reconstruction after July 11, 2005. New engines that commence construction after July 11, 2005, but that are manufactured prior to April 1, 2006, would not be affected by this rule. EPA has clarif ied the applicability language in §60.4200 of the final rule.

7.3 Load

7.3.1 Comment : Two commenters (259, 261) requested that for performance tests conducted by the owners/operators, EPA shoul d specify that the NOx emission standards only apply at full load and that performan ce testing shall be conducted at 90 to 100

75percent of site rated maximum load or ma ximum attainable loa d. The commenters did not specify which particular performance testing requirement they were referring to, but provided, as an example of required perfor mance testing, the annual performance test requirement for engines with a displacemen t of greater than or equal to 30 l/cyl.

The commenters also had concer ns that since certification is only valid for the “useful life” and the operating life for stationary e ngines may far exceed the “useful life” based upon mobile source standards, that additional te sting requirements will be instituted at the State or local level. Thus, it is impor tant that engine operating conditions for performance tests be identified, according to the commenters.

Response : The commenters did not provide any data supporting the claim that performance testing should be conducted at high load. The in-use testing (NTE) requirements specify that engines be run as they are run in actual use, so that if an engine only runs at full load it will be tested at fu ll load, but if it runs on other loads, it can be

tested at other loads. State and local agencies are not prevented from providing additional regulations beyond these regulati ons and such agencies may institute additional testing requirements independent of EPA related actions. EPA believes that the reference to the nonroad testing regulations for engines with a displacement below 30 l/cyl is an appropriate gu ide for other regulatory entit ies. For engines with a displacement of greater than or equal to 30 l/cyl, EPA agrees with the commenter that performance testing should be conducted at high load. These engines are required under the rule to conduct performance testing. For similar regulations, EPA specified that performance testing to demonstrate complian ce should be conducted at high load, e.g., 40

76CFR part 63, subpart ZZZZ and 40 CFR part 60 subpart KKKK, for stationary engines and turbines, respectively. EPA believes it is appropriate to specify that performance testing for engines greater than or equal to 30 l/cyl should be conducte d at high load. The emissions performance data that EPA reviewed and used to establish the final emission limits are based on operation at full load. In addition, although the performance of controls devices may be diffe rent at lower loads, EPA e xpects that if the emission limitations are achieved at high load, then th e technology will be ope rating appropriately and will also operate appropriately at lower loads. The final rule has been written to specify that performance testi ng of stationary CI ICE with a displacement of greater than or equal to 30 l/cyl must be conducted w ithin 10 percent of 100 percent peak (or the highest achievable) load.

777.4 Engines with a Displacement of ≥ 30 Liters per Cylinder

7.4.1 Comment : One commenter (234) expressed th at requiring annual source testing for non-emergency engines with a di splacement of greater than or equal to 30 l/cyl is an exceptionally costly requirement. In Alaska, these costs are exacerbated by the remoteness of some of the installed engines. Even simple source tests require several days of travel by air to remote areas with all required test equipment. Some equipment cannot even be shipped by air, such as co mpressed calibration gases used for Relative Accuracy Test Audits of NOx continuous emission monitoring systems (CEMS). These gases and other chemicals may require ship ping by barges, which only seasonally serve remote areas in Alaska. The commenter sugge sted that the applicable regulatory agency determine the source testing requirements that consider location, costs, intended operation of the unit and the ag ency’s ability to assure continuous compliance with applicable standards.

Response : EPA disagrees with the commenter and believes it is appropriate to require annual source testing from non-emergency sta tionary CI engines with a displacement of greater than or equal to 30 l/c yl. These engines are not certif ied engines like the majority of new CI engines covered by this rule woul d be. For that reason, it is necessary to include requirements that will ensure that the emission standards are met. Source tests are the best way to demonstrate complian ce with the emission standards. EPA is requiring other smaller CI engines to conduc t source testing to demonstrate compliance with standards, e.g., engines subject to sta ndards under 40 CFR part 63. Other units with high displacement located in Alaska are s ubject to source testing to show compliance

78with emission limits, e.g., engines operating at the Nome Joint Utility System Snake River Power Plant. Regarding the comment relating to the cost of source testing, EPA

reviewed information the commenter submitted containing the technical analysis report for the Snake River Power Plant (available from the rulemaking docket). The annual operating cost estimate in that analysis pres ented total annual source test costs for three Wartsila 12V32 engines of $31,500 per year. Per engine, th is equates to about $10,000 per year. This cost is consistent with other cost information EPA has received from a testing firm indicating that to test one engine for PM and NOx (and other pollutants) using EPA methods and conducting three 1-hour test runs at thr ee different operating loads would cost $15,000. Based on source test costs EPA has available, EPA does not believe the costs are exceptionally high. EP A understands that engi nes located in rural areas may be at a disadvantage compared to engines located in non-rural areas. The commenter stated that testing is an ex ceptionally costly requirement (and can be exacerbated by the remoteness of some engine s), but did not provide any information demonstrating that the costs are particularly high. In the absence of specific cost information, EPA does not believe it is appropri ate to discount the cost information in the record based solely on a statement made by the commenter. Manufacturers of high displacement engines have told EPA that an initial performance test followed by annual performance tests are appropriate (see comment 7.4.3). The requirement to conductannual performance testing to demonstrate compliance with the emission limits for nonemergency engines with a displacement of gr eater than or equal to 30 l/cyl has been

retained in the final rule.

797.4.2 Comment : One commenter (240) stated th at §60.4211(d)(3) of the proposed rule

should be revised to make it clear that annua l performance tests will only be required for non-emergency engines with a displacement of greater than or equal to 30 l/cyl.

Response : EPA has made it clear in §60.4211(d)(3) of the final rule that the requirements of that section apply to non-emergency CI engi nes with a displacement of greater than or equal to 30 l/cyl.

7.4.3 Comment : One commenter (235) said that the proposed rule requires that owners/operators of engines with a displ acement of greater than or equal 30 l/cyl demonstrate compliance by first conducting an initial performance test and then establishing parameters to be monitored on a continuous basis. Performance tests are to

be conducted on an annual basis. This is a logical approach, according to the commenter. The commenter provided a reference to a document 6 that lists some process parameters such as intake air humidity recording fo r NOx indication, etc., which will support the proposed approach.

Response : No response is necessary.

7.4.4 Comment : Two commenters (259, 261) were of the opinion that the requirement that units with a displaceme nt of greater than or equa l to 30 l/cyl petition EPA for

6 The commenter referred to appendix 4, chapte r 3, “Alternative approach to CEMS” of CIMACRecommendation – Standards and Methods for Sampling and Analysing Emission Components in Nonautomotive Diesel and Gas Engine Exhaust Gases – Marine and Land Based Power Plant Sources, CIMAC Working Group on Exhaust Emissions, February 2005, available from

” http://www.cimac.com/services/I ndex1-techpaperdatabase.htm

.

80parameter monitoring requirements is onerous and should be repla ced with reasonable monitoring requirements, such as periodic testing.

Response : EPA does not agree and believes it is appropriate to require parameter monitoring for stationary CI e ngines with a displa cement of greater than or equal to 30 l/cyl. Affected units are very large power plants and EPA do es not think that parameter monitoring requirements would be onerous fo r such sources. In fact, commenter 235 agreed with this approach. Periodic testi ng is also required for non-emergency engines on an annual basis. However, to ensure th at the emission standards are being met on a continuous basis, EPA believes that parame ter monitoring is a r easonable and not a burdensome requirement. Once parameters to be monitored have been established, recording the information would require minimum effort, and is not an onerous requirement for the owner or operator. EPA decided not to specify which specific parameters to monitor because the appropriate parameters may be different for each engine. Allowing owners and operators to pe tition for their own specific parameters to monitor provides flexibility and allows s ources to determine the most appropriate indicators of emissions performance. The most appropriate parameters to monitor may differ based on factors such as engine size, location of the engine, fuels, and controls used. EPA has retained this requirement in the final rule.

7.4.5 Comment : One commenter (234) said that th e requirement for owners of units greater than or equal to 30 l/cyl to pet ition the Administrator fo r approval of operating parameters will produce hundreds of petiti ons from Alaska alone. Petitioning the

81Administrator will cause considerable delay in obtaining approval, and adequacy of the compliance plan is not easily deduced from the proposed rule. The commenter recommended reducing the number of parameters to be considered to fuel input, power input, a curve or linear equa tion of urea injection rate vs . either of the previous parameters (SCR), catalyst temperature (SCR), particulate trap delta P and electrostatic precipitator (ESP) voltage/spar kover rate (if ESP can be made “available”). Then, the commenter recommended that EPA require the ow ner to keep records of these parameters on file and available for review by the appr opriate local regulato ry agency. Section 60.4211(d)(2) of the proposed rule is especially inappropriate for emergency engines. Compliance with engine emission standard s is least important when considering emergency operation. The most important fact ors are the ability to start up and respond quickly when needed and operate reliab ly. The commenter suggested delegating authority for the rule to the applicable re gulatory agency to dete rmine source-specific requirements consistent with the title V or SIP program th at considers location, costs, intended operation of th e unit to assure continuous complia nce with applicable standards.

Response : The commenter did not provide any information to support the claim that owners of units greater than or equal to 30 l/cyl petitioning the Administrator for approval of operating parameters will produce hu ndreds of petitions from Alaska alone. It is EPA's understanding that there are just a handful of these units in the U.S. Therefore, EPA does not understand how th is requirement can produce hundreds of petitions from only Alaska. The commenter also did not provide any data to support having fuel input, power input, a curve or linear equation of ur ea injection rate vs. either

82of the previous parameters (SCR), catalyst temperature (SCR), particulate trap delta P and electrostatic precipitator (ESP) voltage/s parkover rate as the only parameters that should be monitored. Therefore, EPA cannot respond to this comment. EPA does not agree that §60.4211(d)(2) of the proposed rule is especially inappropriate for emergency engines, because there are not likely to be many, if any, emergency engines of this large size, and any such engines will, when operational, be significant emitters.

7.5 Startup, Shutdown, and Malfunction

7.5.1 Comment : One commenter (253) stated that the proposed rule appears to require compliance with the emission limitations at all times including periods of startup, shutdown, and malfunction (SSM). Most of the NESHAP and NSPS emission limits do not apply during SSM, e.g., 40 CFR part 60 subpart Dc, which does not require the owner/operator to comply with PM standa rds during periods of SSM (see 40 CFR 60.43c (d)). Consistent with other EPA regulations, EPA should clearly specify in the NSPS that the emission limits do not apply during pe riods of SSM. At a minimum, EPA should replace §60.4206 of the proposed rule with the following provision from 40 CFR §63.6605 of the NESHAP for stationary RICE: “You must be in compliance with the emission limitations and operating limitations in this subpart that apply to you at all times, except during periods of startup, shutdown, and malfunction.”

Response : It is correct that the regulation requires compliance at all times for the majority of engines. This approach is reas onable considering the main structure of this rule, which is a certification program th rough engine manufacturers. Owners and

83operators must operate and maintain the st ationary CI engines in accordance with the

manufacturer’s written instru ctions or procedures devel oped in conjunction with and approved by engine manufacturers, as speci fied in §60.4211(a) of the final rule. EPA does not believe that this requirement s hould not apply during periods of startup, shutdown, and malfunction. The written instru ctions should be followed by the owner and operator at all times to ensure compliance with the emission standards of this rule. However, for engines with a displacement of gr eater than or equal to 30 l/cyl, consistent with previous regulatory decisions such as the NESHAP for stationary RICE, these engines are not required to meet the emissi on standards during periods of SSM. The final rule has been revised accordingly. Alt hough these engines are exempt from meeting emission standards during periods of SSM, the engines must, at all time, including periods of SSM, operate in a manner consiste nt with good air polluti on control practice for minimizing emissions. This requirement is consistent with §60.11(d) of the General

Provisions.

848.0 Add-on Controls

8.1 Comment : One commenter (226) said that the statement on page 14 7 that CDPF require ULSD in order to achieve 90 pe rcent reduction of PM, carbon monoxide (CO), and non-methane hydrocarbons (NMHC) is incorrect. Sulfur tole rant coatings are available for both particulate filters and oxida tion catalyst. The commenter added that the statement on page 22 8 that NOx adsorber technology is a lower cost than SCR technology is questionable. According to the commenter, NOx adsorbers have a high initial cost due to the high platinum conten t, have not yet been proven durable in field applications, and have an associated fuel pe nalty due to the require ment for regeneration. Delivery and storage of urea for stationary applications is mu ch less of an issue than for mobile applications. The commenter said that NOx adsorbers also are not sulfur tolerant.

The commenter further stated that the use of ESP for PM reduction on large bore engines (displacement greater than or equal to 30 l/cyl ) will not be as effective as using diesel particulate filters (DPF). They will not be ve ry effective for any size diesel engines.

Problems with collection of unburned fuel and lu be oil which can foul the ESP elements. This fouling is very difficult to clean. The size of diesel particles can make the design and operating costs for an ESP high. The main reason DPF cannot be used in marine applications is due to the poor quality fuel used on ships. This will be corrected soon as the fuel quality for inland marine applic ations (ferries, barg es, tugs, and dredging equipment) is quickly improving. For stationary applications in the U.S. this should not be an issue. If the exhaust temperature is too low for regenerati on, an inline duct burner,

7 EPA believes the commenter is referring to page 14 of the Word Perfect version of the proposed rule, and not the Federal Register notice, which would be page 39872. 8 EPA believes the commented is referring to page 22 of the Word Perfect version of the proposed rule, and not the Federal Register notice, which would be page 39874.

85electric heating element, or supplemental fu el injection across an oxidation catalyst can be employed to periodically ra ise the exhaust temperature.

Response : The commenter did not pr ovide any data to support the claims made in the comment. EPA is following the approach for nonroad diesel engines as much as possible to ensure consistency between rules. Ma nufacturers have indicat ed that they often produce the same engine for nonroad and stationa ry use. EPA, therefore, believes it is important that the requirements are as simila r as possible to reduce the burden on engine manufacturers and to prevent delays. Regardi ng the claims about sulfur tolerant coatings, the commenter provides no information supportin g its claim. On the other hand, there is voluminous information, including informa tion used to support EPA’s on highway and nonroad diesel engines rules and this rule, that indicate that le vels of sulfur beyond ULSD levels can interfere with regenerati on and can cause clogging of catalyzed PM

filters. The commenter also notes the advers e effect sulfur in fuel would have on NOx adsorber technology. Higher sulfur levels in fuel will also increase levels of sulfur dioxide and sulfate particulate in the exhaus t. See also the comments of commenter 244 on this issue. Regarding the relative be nefits of SCR technology compared to NOx adsorber technology, EPA does not dictate whic h control technologies to use to comply

with the emission standards. Engine manufacturers are free to apply the type of control they believe is appropriate that will ac hieve the required reductions and emission

standards. The NOx adsorber technology is just one technol ogy that can be utilized to meet the emission standards; other technologies such as SCR could potentially be used to meet the standards as well. EPA agrees that both technologies are available for use to

86meet the standards in this rule. For engines with a displacement of greater than or equal to 30 l/cyl, EPA is not requiring that owners and operators use ESP to comply with the standards. EPA is not prohi biting the use of CDPF to m eet the emission reduction and limit; indeed, EPA would welcome the use of such technology if it is shown to be feasible and dependable for such engines; however, the numerical standards are based on the use of ESP. It is up to each indivi dual owner or operator to determine which technology it believes would be best suited for their specific application that would meet the standards, and owners and operators are fr ee to use CDPF if they prefer, as long as

the emission standards are met.

8.2 Comment : Two commenters (259, 261) disagreed with EPA that SCR is technically and economically feasible for a pplication to engines. The ap plication of SCR to engines has been limited in scope and only limited te sting has been conducted for engines with SCR. The efficiency of SCR was another as pect the commenters were in disagreement with EPA on. The commenters could not find any support in the docket for a 90 percent

NOx reduction with SCR. The commenters re ferred to other EPA related actions where EPA had presented different conclusions rega rding SCR applicability. The commenters recommended that EPA provide proper contex t regarding SCR application (i.e., baseload operation) for this standard and consider th e potential deleterious effects from technology

issues such as robust contro l of the reagent feedrate in a varying exhaust. The

commenters said that EPA should revise the SCR-based NOx standard for units with a displacement of greater than or equal to 30 l/cyl.

87Response : Regarding SCR, EPA believes, based on information reviewed, that it is a technically and economically feasible control technology for stationary CI engines.

Several successful installations of SCR have been documented on stationary CI engines as documented in the rulemaking docket. In a meeting with Eur opean manufacturers, EPA was presented with a list of SCR applications to large displacement engines in several locations. Nearly all these engines cited NOx emission reduc tions of at least 90 percent (EPA-HQ-OAR-2005-0029-0146). EPA eval uated the cost of SCR control per

ton of NOx removed and determined that the cost per ton was reasonable. More information on this analysis can be found in the rulemaking docket in the memorandum

entitled “Emission Standards for E ngines with a Displacement of > 30 Liters Per Cylinder.” The commenters stated in their letters that source tests included in the docket showed that performance testing conducte d on two engines equipped with SCR showed one engine achieving 85.0 to 86.5 percent reduction and the other achieving 90.7 to 94.2 percent reduction for NOx. The engines th at were tested were Cummins QSK60-G6 diesel engines (rated at about 2,700 hp). The co rrect citation for this test report is EPAHQ-OAR-2005-0029-0043. However, there are also source tests in the docket for several Caterpillar 3516B diesel engines with SCR (EPA-HQ- OAR-2005-0045). Test results from two of these engines equipped with SCR showed NOx reduction efficiencies ranging from 91.1 to 91.8 percent reduction for one engine, and 93.1 to 95.2 percent reduction for another engine. Engine manuf acturers and control technology vendors have also indicated that NOx reduction of 90 percen t with SCR on diesel engines is possible (EPA-HQ-OAR-2005-0029-0036, 0038, 0044 and 0055). In early 2004, catalyst vendor

Miratech indicated that is had installed between 70 to 80 SCR systems on stationary

88engines in the U.S., and more than 1,000 installations worldwide (EPA-HQ-OAR-2005- 0029-0051). For the final nonroad CI engine ru le, EPA stated that there are several stationary diesel generator sets currently using SCR (69 FR 38979). In addition, EPA stated in the Final Regulatory Analysis fo r nonroad CI engines that SCR can reduce NOx emissions by more than 90 percent. 9 This was supported by a test program conducted by

the Manufacturers of Emission Controls Association (MECA) conducted on a 1998 12.7

liter Detroit Diesel 400 hp Series 60 engine. 10 As summarized in the below comment from commenter 244, the commenter discussed r eal life successful experience with SCR on stationary engines. Comm enter 244 indicated in the comment letter that SCR is a proven technology and has recently been applied to mobile sources such as trucks, marine vessels, and locomotives. The technology is exp ected to be used on mobile CI engines in Europe to meet European NOx emission standards. Commenter 244 stated in their

comment letter that since the mid-1990s, SCR technology usi ng urea-based reductant has been used on various marine applications in Europe including installations such as ferries, cargo vessels, and tugboa ts totaling more than 100 sy stems on engines ranging in size from 450 to 10,400 kW. The commenter also stated in their comment letter that in 2001, a gantry crane powered by a 850 kW dies el engine was equipped with SCR and

DPF in California. The combined contro l system was expected to reduce PM by 85 percent and NOx by 90 percent. In addi tion, commenter 244 stated that a similar combination system has been installed on st ationary diesel powe r production engines in

9 Final Regulatory Analysis: Control of Emissions from Nonroad Diesel Engines. Environmental Protection Agency, Office of Transportation and Air Quality. EPA420-R-04-007. May 2004.

10 Demonstration of Advanced Emission Control Technologies Enabling Diesel-Powered Heavy-Duty Engines to Achieve Low Emission Levels. Final Report. Manufacturers of Emission Controls Association. June 1999.

89Southern California. These engines were Caterpillar 3516B engines. The commenter also cited a 2004 announcement by Volvo, which stated that the company has launched a combined SCR/DPF system on their diesel transit buses to meet European emission limits. Similar applications have also been employed in the U.S., according to

commenter 244. Further details can be found in the commenter’s letter to EPA. A recent article published in Power, stated that dies el engines routinely achieve 90 percent NOx reduction; sometimes higher reductions are possible (EPA-HQ- OAR-2005-0029-0203).

Commenter 265 indicated in thei r state-of-the-art (SOTA) ma nual that NOx reductions of 90 to 98 percent are possible with SCR. EP A is finalizing a NOx emission standard for engines with a displacement of greater than or equal to 30 l/cyl of 1.6 g/kW-hr (1.2 g/hphr). EPA believes the proposed NOx sta ndard of 0.40 g/kW-hr (0.30 g/hp-hr) was too stringent. EPA is also finalizing the proposed NOx percent requirement of 90 percent. A source must meet either of these requirements , but need not meet both. EPA explains its reason for changing the emission standard a nd the appropriateness of increasing the NOx standard for large displacement engines in the responses to comments in section 16.5. Regarding the comment related to other EP A related actions, which occurred several years ago, newer information EPA has obtained indicates that SCR is a viable control strategy for these engines. As discussed in this response to comment and demonstrated by several successful installations, SCR is a t echnology that is feasible on stationary CI engines, and EPA strongly beli eves that SCR is BDT for e ngines with a displacement of greater than or equal to 30 l/cyl and as summarized here and as documented in the docket, 90 percent reduction with SCR is clearly possible.

908.3 Comment : One commenter (244) provided summa ries including capabilities and experience for a variety of emission cont rol technologies including DPF, SCR, NOx adsorbers, lean NOx catalysts, exhaust gas recirculation, and diesel oxidation catalyst (DOC) and crankcase emission control technologies.

Response : EPA appreciates the detailed discussi on of control technologies provided in this comment. EPA agrees that DPFs are co mmercially available today and have already been used in numerous applic ations, including sta tionary applications. EPA agrees that SCR technology is a proven NOx control strate gy for stationary sources and for diesel engines in general. EPA also agrees with comments related to DOCs, NOx adsorbers, lean NOx catalysts, exhaust gas recirc ulation, and crankcase emission controls.

9.0 Research and Development

9.1 Comment : One commenter (229) requested that EPA exempt stationary CI engines used solely for the purpose of testing, research, and development from the requirements

of the rule.

Another commenter (262) said that there are certain ci rcumstances in which the owner/operator of stationary CI ICE must deviate from the engine manufacturer’s recommended operating and maintenance paramete rs in order to perform research related to a variety of issues. Commenter 262 reque sted that a provision be included that exempts engines used in various types of research studies. This commenter added that the number of engines utilized for these purpos es is small when compared to the total

91number of stationary CI ICE currently in use. These engines are al so smaller engines in most cases, typically less than 500 hp, and are not normally operated on a 24-hour per day, 7 day per week basis. Therefore, such an exemption would have a negligible impact on the expected emission reductions that wi ll be achieved by the proposed changes.

Response : EPA agrees with the commenters that it is appropriate to exempt stationary CI engines used for research and development purposes. A provision exempting such engines is already included for the nonroad regulations parts 89 and 1039. In those provisions, the engines are referr ed to as test engines. EPA refers to various parts of the nonroad regulations and the specific sections of the nonroad regulations that address research and development engines are 89.905 and 1068.210 apply to stationary engines covered by this rule.

10.0 Definitions

10.1 Emergency

10.1.1 Comment : One commenter (236) said that b ecause there is no time limit on the use of an emergency CI engine in emergency situations, it will be critical that both the operators of these emergency generators, a nd the authority having jurisdiction enforcing this rule, both have a common understanding of the term “emergency situation.” In the healthcare community, an emergency situation is an unplanned event that requires a rapid response to minimize the negative impact to pa tient care outcomes. In addition to power outages, hospitals are highly su sceptible to power fluctuatio ns, which can cause erratic

92operation of computer based diagnostics, ther apeutic, and patient monitoring equipment. In response to fluctuating power conditions hospitals must manually start their generator(s) and transfer critical loads to maintain power reliability. During high power demand days hospitals may be requested by the local utility to run their generators to curtail (lessen) their relian ce on utility power thereby stabilizing the power grid serving the community. The commenter urged that EPA clarify “emergency situation” with provisions for these scenarios. Hospital emergency generator systems are extremely well

maintained so as to meet their char ge of continuous standby operation.

Another commenter (243) stated that EPA must provide an adequate definition of what constitutes an “emergency.” Suggested elements of the definition of and “emergency” and “emergency generator” are provided in the comments.

Another commenter (238) was of the opinion th at the definition of emergency engines is incomplete. This definition does not adequate ly describe emergency situations or allow facilities that produce their own power to use emergency engines if their own power generation sources go off-line or down. The commenter recommended the following definition: “A stationary internal combustion engine that operates as a mechanical or electrical power source only when the usual supply of power is unavailable, and operates for no more than 500 hours per year. The 500 hours of annual operation for the engine include operation during emergency situa tions, routine mainte nance, and routine exercising (e.g., test firing the engine for one hour a week to ensure reliability).

93Stationary internal combustion engines us ed for peak shaving generation are not emergency power generating stationa ry internal combustion engines.”

One commenter (267) said that EPA should include fire and other situations that would call for interruption of power and necessita te ancillary generator operation in the definition of emergency engines. Vague regulatory language not only compromises environmental quality and the public, but it adds to the operation costs of facilities. Vague regulatory language also spawns litigati on when interested parties begin to dispute the meaning of a given rule. Legal disput es hinder environmental protection and add more costs to doing business, by causing delays in implementation and creating a climate of investment uncertainty.

One commenter (269) assumed that a generator (at a manufacturing facility) is considered an “emergency” generator if its prim ary purpose is to handle: 1) Power outages/interruptions to allow continued operation of emerge ncy lights, fire protection systems, water supply pumps, computers, etc., 2) Testing activities to test periodically to ensure the unit is still operational, and/or 3) Pending power losses when generators are operated to avert an imminent power loss or power spike resulting from poor weather conditions (i.e., approaching storm). Howeve r, would EPA still consider these same units “emergency” generators if they ALSO were on occasion, used to operate for peak shaving, the commenter asked. Peak shaving occurs during poor weather conditions such as extremely hot summer days or cold winter days where the facility will voluntarily, or at the request of the utility company, curta il energy usage. Since operation of these

94generators for peak shaving is: 1) not its primary function, 2) triggered by unforeseeable conditions such as weather, and 3) an abnor mal situation that does not occur on a regular basis, the commenter asked if the unit still is considered an “emergency” generator.

One commenter (251) said that the discussion in section III.C.7 of the preamble to the rule should also include, as an example of an emergency situation, the use of emergency engines as critical backup operations for sa tellite tracking stati ons. Department of Defense standard operating procedures require the operation of sta ndby generators during initial launches of satellite systems. Th ese emergency stationary CI ICE ensure

continuous critical communications that are n ecessary to prevent loss of facilities and flight hardware in case of a failure in the prime source of power. The use of CI ICE as critical backup operations for satellite tracking stations should be considered an “emergency situation” and, in accordance with §60.4211(e), the rule should not limit their use in these operations. The comme nter proposed the following language be included under section III(C)(7) of the pr eamble to the final rule: “Examples of emergency operation also include backup pow er for initial launch tracking of U.S. Department of Defense flight hardware (in parallel with grid power), where the loss of normal power would cause damage to or loss of government facilities and/or flight

hardware.”

Another commenter (266) believed that site or facility relate d interruptions such as an onsite fire or other situations should be included in the defi nition of emergency engines and recommended that “a site or facility-speci fic interruption occurs” be added to the

95definition of emergency engines. It should be specified that the maintenance checks and readiness testing should include thos e that are required by the NFPA.

Response : EPA believes it has provided an adequa te definition of emergency stationary internal combustion engine. EPA feels that it is not necessary to include more examples of emergency operation. To cover all possi ble scenarios that would constitute an emergency in the definition would be nearly impossible. EPA notes that fire pumps are already listed as an example of emergency en gines, and engines that operate only during fires and other onsite emergencies would obvi ously qualify as emergency engines. Regarding power fluctuations, EPA understa nds there may be crucial needs at e.g., hospitals, to ensure power re liability. EPA agrees that power fluctuations would be considered an emergency situation. Also, it would not be appropriate to limit the time allowed to be spent during emergency opera tion (see discussion in section 3.0 of this document). EPA believes it would be appropriate to consider facilities that generate their own power in the definition of emergency e ngine and has revised the definition to add “or the normal power source, if the facility runs on its own power production,” to account for facilities which do not rely on power from the local utility. Consistent with other regulations for stationary engi nes, peak shaving is not considered emergency use. This issue is discussed in response to comments in section 17.0 of this document. Peak shaving is a relatively planned activity perf ormed for basic energy generation during peak periods, not for unplanned emergencies like fires, floods, or natural disasters. In addition, peak shaving involves income generation, whic h is not an emergency activity. Further, engines can certainly be used for peak sh aving, but if so, they are not considered

96emergency engines and would not be exem pt from meeting the more stringent requirements applicable to non-emergency engi nes. EPA has revised the definition of emergency engine to specifically state that engines used to supply power to an electric grid or that supply power as part of a financial arrangement with another entity are not considered emergency engines. EPA agrees with commenter 243 that any operation that is intended to supply power for distribution to the electric grid would not be emergency operation, like peak shaving, peaking powers un its, or standby units. EPA believes that the definition of emergency engine is reasona bly clear on this point. In response to the comment related to engines used for Depart ment of Defense satellite launch backup purposes, these are likely to be exempt under na tional security exemptions in parts 89 and 1068, which EPA refers to in the rule for stati onary engines. EPA believes this addresses the commenter’s concern regarding engines us ed for such purposes. EPA agrees that

maintenance should be included in the definiti on. This is consis tent with §60.4211(e) of regulation and EPA has incorporat ed this change into the de finition of emergency engine

into the final rule.

10.2 Stationary Internal Combustion Engine

10.2.1 Comment : One commenter (247) said that th e definition of stationary internal combustion engine is confusing. The proposed §60.4216 says that a stationary ICE is one

that is not mobile. It furt her states that a stationary ICE is not a nonroad engine as defined by 40 CFR 1068.30. The definition in 40 CFR 1068.30 contains two paragraphs: paragraph (1) describing engines that are nonroad engines and para graph (2) describing exceptions. Paragraph (2)(ii) of 40 CFR 1068.3 0 excludes an engine subject to NSPS.

97Thus an engine is excluded from the propos ed NSPS as long as it is not subject to the proposed NSPS.

The commenter wanted the part that says a stationary ICE is not a nonroad engine as defined by 40 CFR 1068.30 clarifie d to explain how to inte rpret the sentence in the nonroad engine definition in 40 CFR 1068.30 that sa ys that an engine that is regulated under an NSPS is not a nonroad engine. Must engines described under paragraph (1)(iii) of the definition of nonroad engines in 40 CFR 1068.30 comply with the proposed NSPS and thereby lose their status as nonroad engines, the commenter asked.

Response : A stationary internal co mbustion engine is any stat ionary internal combustion engine, except combustion turbines, that conver ts heat energy into mechanical work and is not mobile. Stationary ICE differ from mobile ICE in that a stationary internal combustion engine is not a nonroad engine as defined at 40 CFR 1068.30, and is not used to propel a motor vehicle or a vehicle used solely for competition. EPA agrees with the

commenter that the definition in the proposal is somewhat uncl ear in that there appears to

be mutual exclusions in the definitions of nonroad and stationary engines. EPA has revised the definition of stationary engine to exclude the reference to paragraph 2(ii) of the definition of nonroad engine. Thus, any engine meeting the substantive definition of a nonroad engine in part (1) of that definition, and not excluded under part (2)(iii) of that definition, would not be considered a stat ionary engine. Engines described under paragraph (1)(iii) of the definition of nonroad engine in 40 CFR 1068.30, and not excluded under section (2)(iii) of that definition, would be considered nonroad engines

98and would not have to comply with the CI NSPS, which applies to stationary engines only. EPA believes this response ad dresses the commenter’s concerns.

10.2.2 Comment : One commenter (265) recommended th at the definition of stationary internal combustion engines be revised to include portable electric generating engines, which are connected to the commercial power grid for any time period. Some power companies have sought to use diesel gene rators for peak summer electric demand periods, trying to fit within the definition of nonroad engine. Any engine connected to the power grid should be consid ered a stationary source, whet her or not it is moved prior to the time period specified within the definition of nonr oad engine. The proposed definition appears to exempt a ll portable or transportable e quipment remaining on site for less than 12 consecutive months, even if connected to the commercial power grid.

Response : As stated in 40 CFR 1068.30(1)(iii), nonr oad engine means t hat, by itself or in or on a piece of equipment, is portable or transportable, meaning designed to be and capable of being carried or moved from one location to another. Indicia of transportability include, but are not limited to, wheels, skids, carrying handles, dolly, trailer, or platform. Portable electric generating engine s that remain in one location for

less than 12 consecutive months are consid ered nonroad engines and are subject to requirements for nonroad engines. This defini tion is consistent with how EPA has treated nonroad and stationary engine s in the past, and EPA does not believe it would be appropriate to alter the defin ition of a stationary engine to include engines that are portable that remain in one location for less than 12 consecutive months.

9911.0 Rule Structure

11.1 Comment : One commenter (238) made the commen t that the layout of the proposed

rule is hard to follow. The commenter reco mmended the rule be st ructured in the same manner as other NSPS rules, where the first se ction of the rule deal s with applicability issues, the second deals with de finitions, etc. The emission li mits should be included in

the rule in a clear and concise ma nner. It is not fair to the pu blic to have to refer to other EPA regulations to determine which sta ndards and provisions apply in any given situation. To the extent practi cable, all provisions that are to apply to CI engines must be expressly presented in the NSPS. Placing th e standards explicitly in the NSPS will avoidthe risk of inadvertently incorporating something that works well for the manufacturerbased compliance and enforcement of mob ile source regulations, but would not be compatible with permittee-based compliance enforcement for stationary regulations. E.g., mobile regulations contain tampering provisions that prohibit modification of emission control systems, even if the modifi cation leads to lower emissions. This is incompatible with stationary source permitting where the source has a compliance responsibility and may need to upgrade the em ission control system at some point during the life of the engine. For the same reas ons, emission control systems upgrades cannot

void manufacturer’s warranties.

Another commenter (240) said that EPA should provide a summ ary chart in the final rule setting forth all the applicable emission st andards and effective dates for emergency engines.

100One commenter (264) urged EPA to clarify the emission standards contained in §60.4202(a) of the proposed rule. The proposed language consists of one extremely long sentence that incorporates several provisions from EPA’s Tier 3 a nd Tier 4 nonroad rules for diesel engines. This a pproach is very confusing a nd the commenter urged EPA to summarize the applicable requirements in a table.

Response : EPA believes the structure of the ru le is appropriate and is in general consistent with the layout of other NSPS rule s. EPA has kept the references to other rules at a minimum, but certain references ar e necessary since those are the standards and requirements that stationary CI engines will have to comply with. The nonroad engine regulations generally require se veral separate sets of emissi on standards to be met, and there is little reason to copy them into a new part of the CFR. EPA wishes to limit repeating standards that can be found elsewh ere. Furthermore, engine manufacturers, who for the most part will be the party subj ect to the emission standards are already familiar with the requirements in the regula tions for nonroad diesel engines. Also, by referring to the emission standards in the nonr oad rules (and marine rules) eliminates the need of having to potentially revise the NSPS rule should changes be made to the

nonroad and/or marine rules. EPA intends to keep the stationary and nonroad diesel engine requirements consistent. Also, EPA is limiting repeating language and requirements that are already established in other parts. EPA has included as many provisions explicitly in the rule as possibl e to minimize referring to other rules and believes the references as proposed are necessary. EPA has included the emission

101standards in the proposed rule for some e ngines where the emission standards may be

different than those that a pply for nonroad diesel engines. EPA agrees that §60.4202(a) of the proposed rule (specifying emission st andards for emergency engines) could be

difficult to understand. EPA has restructured §60.4202(a) in the fina l rule and believes that the requirements as writt en in the final rule can be clearly understood. EPA notes that EPA has generally enforced the tampering provisions of the CAA only when the

modifications would tend to l ead to increased emissions.

11.2 Comment : One commenter (238) expressed th at the limits for NOx + NMHC need to be amended to separate emission limits for NOx and NMHC or just establish a NOx limit. The key factor in determining what type of a permit a facility should apply for and what regulations may apply to a facility is a facility’s potential NOx emissions. In order to properly estimate the NOx emissions from CI engines, the NOx emission rate from

these sources must be known. The term “HC” is not defined in table 1 of the proposed

NSPS.

Response : EPA does not agree with the comment er that there should be separate

emission limits for NOx and NMHC. The combined NOx + NMHC limit is consistent with the limits for nonroad diesel engines, wh ich helps to facilitate the certification program for stationary engines. In additi on, NMHC is an ozone precursor and emissions of NMHC should therefore be regulated. B ecause NOx and NMHC are both regulated as ozone precursors and there can be an inverse relationship be tween reductions in NOx and NMHC, EPA believes that having a combined st andard provides needed flexibility to

102reduce total emissions of the two pollutants. Estimating the potential NOx emissions from a source for permitting purposes is outside the scope of this rulemaking and having a combined emission limit does not prevent sources from estimating their NOx emissions. EPA does not feel that it is necessary to define the term “HC” in table 1 of the proposed rule.

12.0 Labeling

12.1 Comment : One commenter (238) said that the label restricting certain engines to emergency use only could lead to confusion in cases where such engines are equipped with post-combustion pollution c ontrol equipment that meets a ll applicable standards. The wording on such labels needs to be flex ible enough to account fo r this possibility.

Response : The provisions in §60.4210(f) of the proposed rule were included because emergency engines are not required by the rule to meet emission standards that are based on the use of aftertreatment, so EPA expects that the majority of emergency engines will comply with the emission standards that do not require aftertr eatment. Therefore, separate labeling of these engines is necessa ry to distinguish them from non-emergency engines. EPA understands that it may be possible that emergency engines may be equipped with aftertreatment controls. The provisions in §60.4210(f) of the proposed rule also account for this possibility. Ther e is nothing in §60.4210(f) of the proposed rule that restricts an emergency engine to emergency use onl y if the engine meets the emission standards for non-emergency engi nes in §60.4201 of the proposed rule, and in

103such case, a permanent label stating that th e engine is for emer gency use only is not required, as stated in §60.4201( f) of the proposed rule.

12.2 Comment : One commenter (240) stated that the labeling requirements need to be fully coordinated and aligned with the labeling requirements under the nonroad and marine engine rules. In that regard, a single, uniform labe l should be utilized whenever feasible. Certification-type labeling of Tier 1 (or other pr ior Tier) engines should not be required. The proposal to make the la beling requirements of 40 CFR part 1068 applicable to stationary engine s in advance of Tier 4 requirem ents is inconsistent with the nonroad and marine engine rules (where th e 40 CFR parts 89 and 94 labeling provisions will continue to apply to Tier 2 and Tier 3 en gines) and so will create unique, inconsistent and unworkable labeling requirements for stationary engines. The commenter provided a chart summarizing certain princi pal labeling inconsistencies at issue under the pending proposal.

Response : EPA generally agrees that the labeling requirements for stationary CI engines

should be consistent with the nonroad and mari ne engine rules and that a single label is preferable whenever feasible. EPA agrees that labeling of cer tified engines meeting current part 89 or part 94 st andards should meet the labeling requirements in those parts. EPA has revised the labeling requirements in part 1068 for non-certified engines or engines certified to earlier tiers and has clar ified the labeling requirements in the final rule pursuant to discussions with the commenter .

10413.0 Recordkeeping and Reporting

13.1 Certification Records

13.1.1 Comment : One commenter (250) said that it does not make sense for EPA to require owners/operators to obtain and keep the certification records as required in §60.4214(a)(2)(iii) of the proposed rule. The Office of Transportation and Air Quality (OTAQ) has the certification data for all certified nonroad diesel engines. Section 60.4214(a)(1) of the proposed rule would requir e an owner/operator to submit an initial notification with the make, model, engine fa mily, serial number, etc. Thus, EPA would have more than enough information from wh ich to identify and acce ss the certification information at OTAQ related to the particular stationary CI ICE, without requiring an owner/operator to obtain and maintain this information.

Response : EPA disagrees with the commenter’s st atement that it does not make sense for engine owners/operators cove red by this requirement to keep documentation that the engine is a certified engine. EPA does not think that this is an unreasonable burden for engine owners and operators and also it allows other enforcing agencies such as States to

have access to the information. EPA is not re quiring that all certific ation data be kept, only that documentation of certification be kept. Also, §60.4214(a) of the proposed rule only applies to a limited number of engines and not all engines covered by the rule are subject to this requirement. In fact, the vast majority of engines will not be required to keep this information. Also, many of the engi nes covered by this requ irement will not be certified (e.g. engines with displacement greater than 30 l/cyl and uncertified pre-2007

105engines), so the information regarding certifi cation is relevant and important for engines subject to this requirement.

13.2 Hour Meter and Other Compliance Requirements for Emergency Engines

13.2.1 Comment : One commenter (238) was of the opinion that the owner/operator of emergency engines should be required to keep records of all situations, including emergency situations, when the engine is use d, in order to determin e compliance with an annual cap on the hours of operation.

Another commenter (243) stated that if EPA promulgates different requirements for “emergency” engines, EPA must impose enforc eable limits so these engines are used only in clearly defined emergencies. By exempting “emergency” operation from the reporting requirements, allowing emergency en gines to run for an unlimited number of hours during “emergencies,” and failing to provi de a definition of what constitutes an “emergency” situation, the proposed rule l eaves a highly problematic loophole. To ensure compliance with the rule, EPA must require reporting for all operation of emergency engines, emergency situations as we ll as required testing. Many states require reporting of both emergency and non-emergenc y use, e.g., the California ATCM requires a monthly log of all operation by emergency engine s. To ensure that reporting is required of the entire class of emergency engines, EP A must require that all emergency engines be registered with the Agency. The additional registration and reporting requirements will greatly enhance EPA’s ability to enforce the new rules and will discourage owners and

106operators from illegally purchasing engines that are certified only for emergency use, but operating them in non-emergency situations.

One commenter (236) stated that thor ough documentation of operating hours and operating conditions is currently maintained at hospitals. In recogni tion of this “already in place” practice of documentation, the comm enter urged EPA to allow hospitals to document the “emergency situation” entire run conditions utilizing current logs, with no further data collection requireme nts (e.g., climatic data reports, service tickets, letters from utility companies, etc., are not required).

Another commenter (266) stated that additional recordkeepi ng (above what is already in place) should not be required.

Response : EPA is revising its recordkeeping requi rements to require that an owner or operator of an emergency engine keep records of all operation of the emergency engine. This will ensure that there is documentation that the engine was operating in emergency situations when it was running beyond the a nnual limits permitted for maintenance and testing. There is no annual cap on the hours of operation during an emergency situation, but it is important to have documentation th at such operation was indeed for emergency purposes. Commenters indicate that owners and operators of emergency already keep documentation of when and why such engine s were operated. EPA’s recordkeeping requirement requires no more than this. EPA does not believe it is a ppropriate to require reporting (as opposed to recordkeeping) for emergency engines and believes requiring

107such reporting would be a burdensome and unne cessary requirement. Given the number of emergency engines purchased each year (EPA estimates that more than 65,000 new stationary CI emergency engines will be sold in 2015) and the level of their usage, EPA believes that requiring reporting will create needless paperwork that will not result in

substantial further enforcement. EPA believe s the requirement for recordkeeping and the requirement for an hour meter will serve as a significant deterre nt and a sufficient compliance tool. EPA is including an additiona l requirement in the final rule that owners and operators log all periods in which the emergency engine was used for emergency purposes and the nature of the emergency. If the owner or operator already keeps such information, which EPA believes (and comment ers say) may often be the case, no more information would be needed to indicate emergency use. EPA does not believe it is appropriate to require registration of all emergency engines put into operation after the rule is in place. EPA believes that this would be a paper exercise of monumental proportions, given the number of engines that would need to re gister, with little practical

result. EPA notes that State and local authorities may require more substantial compliance requirements in areas where such authorities believe it is appropriate.

13.2.2 Comment : One commenter (240) stated th at §60.4209(a) of the proposed rule

should be revised to account for the fact that a non-resettable hour meter will not be able to distinguish between engine operation dur ing maintenance and r eadiness testing, and engine operation during actual emergencies wh en hour limits on operation do not apply. The rule should simply require that the owne r/operator keep record s of engine operation during non-emergency situations utilizing a non-resettable hour meter.

108One commenter (264) stated that it is not aware of a method that wi ll accurately track the non-emergency hours of operation of an em ergency engine. The non-resettable hour meter required in §60.4214(b) of the propos ed rule cannot distinguish between emergency and non-emergency service. The commenter urged EPA to delete this provision from the rule.

One commenter (259) recommended removing the requirement for an hour meter for emergency engines. Manual records will st ill be required to differentiate between emergency and non-emergency service, so a manual log of non-emergency run time is adequate.

Response : EPA is not implying that the hour mete r is capable of di stinguishing between emergency and maintenance and testing operati on. EPA expects that an operator or technician would be the one to distingui sh between emergency and non-emergency hours and would record the hours of operation during non-emergency operation. The hour meter would have to be read pr ior to the start of maintenanc e and testing activities and at the conclusion of such activities, and th e total hours spent during non-emergency operation would be recorded. This is what th e rule requires to ensure that the 100 hours per year limit during non-emergency operation is not exceeded. EPA believes that it is appropriate to require that an hour meter be installed and does not agree with the commenter who recommended not including th is requirement. Most stationary CI engines come equipped with an hour meter and EPA believes that requiring an hour

109meter will not be a burdensome requirement. The use of the hour meter will ensure that the recorded hours are as accurate as possibl e and will eliminate the need to manually track the exact hours of operation.

13.2.3 Comment : One commenter (250) made the comment that the requirement to keep records of the operation of the emergency engine in non-emergency service is inconsistent with how EPA regulates othe r new/reconstructed emergency stationary engines under 40 CFR part 63, subpart ZZZZ for st ationary RICE. In that rule, EPA does not require new/reconstructe d emergency RICE to meet any of the reporting and recordkeeping requirements of subpart ZZZZ or the General Provisions except for initial notification. Moreover, there is no provi sion in subpart ZZZZ of 40 CFR part 63 to maintain records of the non-emergency use of this equipment. The commenter did not

see the environmental benefit to includ ing this requirement in the CI NSPS.

Response : The NSPS for stationary CI e ngines and the 40 CFR subpart ZZZZ for stationary RICE are completely separate rule s. In subpart ZZZZ there is no time limit on the use of emergency engines for maintenance a nd testing, so therefore there is no need to require owners and operators to maintain reco rds of this use. Furthermore, emergency engines do not have to meet any emission standa rds in that rule. However, in this rule, EPA is limiting the hours of operation during ma intenance and testing, and to ensure that the non-emergency hours of operation limit is not exceeded, EPA is requiring that owners and operators record the hours spent during ma intenance and testing and maintain these records. Clearly, this requirement yields environmental benefits since it will limit the

110likelihood that sources subject to the rule that operate em ergency engines would exceed the 100 hour annual non-emergency limit. In the absence of monitoring and recordkeeping requirements, this requirement would not be enforceable. For these reasons, EPA believes the requirement as proposed is appropriate.

13.2.4 Comment : One commenter (267) strongly urged EPA to provide clear and reasonable recordkeeping requirements with respect to maintenance of stationary engines

in order to reduce business cost s, and assure consistency in the maintenance of stationary engines. The proposed rule caps engi ne testing at 30 hours per year, and owners/operators should not be required to keep records for testi ng beyond the amount of time specified within the proposal.

Response : The commenter did not specify wh at provisions of the recordkeeping requirements are unclear or unreasonable, or how these requirements would increase

business costs or lead to in consistency in the maintenan ce of stationary engines. Therefore, EPA does not have any basis fo r addressing the commenter’s concerns. Regarding the commenter’s statement that ow ners/operators should not be required to keep records for testing beyond the amount of time specified within the proposal, EPA is unclear on what type of records the commenter is referring to.

13.2.5 Comment : One commenter (243) claimed that EPA’s proposal failed to establish policies that enforce any mean ingful distinction between em ergency and prime engines.

111The commenter states that the Federal a nd State regulators have extremely limited resources to track an engine’s use throughout its life in the stream of commerce.

Response : EPA disagrees strongly with the co mmenter. EPA is imposing enforceable clear labeling requirements limiting emergenc y engines to emergency use only, if the engine is not certified to Ti er 4 emission standards. This requirement is included in §60.4210(f) of the final rule. In addition, as noted above, EPA is re quiring owners and operators to keep records of all operation of the emergency engines, and requires an hour meter to provide further verification. This requirement is intended to make records available to enforcing agencies to ensure th at owners and operators do not operate outside of acceptable usage. EPA is also clarifying th e regulations to state explicitly in section 60.4211(e) that any operation other than emer gency operation, and required maintenance and testing, is prohibited. EPA understands that, given the number of emergency engines in the country, it will be impossible to ensure that all engines always operate according to the regulations. This is true with regard to any regulation. However, the regulations provide considerable ability for enforcement agencies to check operation and the regulations, including the la beling requirement, provide ample warning that operation outside emergency conditions, ot her than required maintenan ce and testing, is prohibited. Given the penalties for violation of the N SPS, the requirements for recordkeeping, and the manner in which these engines are nor mally used, EPA does not believe that

substantial nonconformance is lik ely. In addition, EPA has included a requirement in the final rule that engine manufacturers must sp ecify in the owner’s manual that operations for emergency engines are limited to emer gency operations and required maintenance

112and testing. This will ensure that the engine is used appropriately and EPA believes that in most cases the engine manufacturers al ready include this. EPA also notes that emission reductions will be realized by em ergency engines meeting Tier 2 and Tier 3 emission standards, and it is not unlikely that some emergency engines will be certified to Tier 4 emission standards. Indeed, State a nd local authorities are not preempted from requiring emergency engines to meet more stringent standards, or more stringent compliance requirements, in areas where the local authority believe such regulation is appropriate.

13.3 Notifications

13.3.1 Comment : One commenter (259) questioned the necessity of the notification requirement. EPA solicited comment on notification for engines in addition to those specified in §60.4214 of the proposed rule, and the commenter believed that the notification requirements should not be ex tended beyond the units currently proposed. The commenter recommended deleting the not ification requirements in §60.4214 in the proposed rule for all engines. The comme nter did not understand the need for any notification requirements, as the owner/operato r bears responsibility to conform to the requirements of the standard. In addition, other State or Federal programs will likely require a permitting action for larger engines th at are also subject to subpart IIII. In response to EPA comment solicitation, at a minimum, the commenter recommended that notification requirements not be extended any further than currently proposed.

113Response : EPA proposed notification requirements for certain stationary CI engines in §60.4214(a) of the rule. As explained in the preamble to the propos ed rule, an initial notification requirement is a ppropriate for those engines because many of those engines will not be certified engines. Certified engi nes are warranted by the engine manufacturer that it will achieve the certified engine emi ssion levels for the usef ul life of the engine. Engines that have not been through the certification process will be required to demonstrate compliance with the emission standards in other ways. Owners and operators of non-certified engine s will have to keep records indicating that their engine

meets the emission standards. The initial not ification requirement for these engines is

intended to alert State and local agencies of the presence of these non-certified engines. Similarly, EPA felt that an initial notificati on requirement would be appropriate for very large engines, even if certif ied, because enforcing agencies may want to track these engines individually. Finally, engines with a displacement of greater than or equal to 30 l/cyl are not required to be cer tified, therefore, an initial no tification requirement for these engines is also appropriate. The initial notification requi rement is not a burdensome requirement and EPA estimates that minimal effort would be invol ved in preparing and submitting an initial notification. The notification requirements remain as proposed in

the in the final rule.

14.0 Fire Pumps

14.1 Comment : One commenter (239) said that the transition period which allows manufacturers the time necessary to have the Tier 3 units approved by Underwriters Laboratories and Factory Mutual is an excellent proposal. Howe ver, in the interest of the

114environment, the commenter suggested th at current production engines should be regulated to a minimum of Tier 1 standards, as this technology al ready exists. Pump manufacturers build vertical turbine, and horizontal split case pumps for fire pump service. They have the t echnology and are building today mu lti-stage vertical turbines and dual-stage split case pumps, which woul d supply the high pressures needed when using lower revolutions per minute (rpm) Tier 3 engines. High speed engines are not necessary for emergency fire pump duty. High speed Tier 3 engines already exist and are being manufactured by more than one major e ngine supplier. This can be confirmed by looking at the product availability from Deutz, Iveco, Caterpillar and others. It is the commenter’s opinion that the additional 3 year extension requested by commenter 248 is a marketing ploy, not in the interest of prot ecting the environment. The extension would

allow commenter 248 to continue manufacturing their substand ard engines for the next 6 years, as commenter 248 knows that this commenter, and other corporations, will not be able to sell Tier 0, 1, and 2 engines since only Tier 3 engines will be manufactured and available from the engine suppliers. Commenter 248 would subsequently enjoy a monopoly in the marketplace on high speed engines because of the lower cost of building Tier 0 and Tier 1 engines. This commenter agreed with the intent of the proposal, but questions the motives behind the 3 year extension.

Response : In response to the comment stati ng that EPA should regulate current production engines to a minimum of Tier 1 standards, as th is technology already exists, EPA is regulating emergency fire pump engine s to emission standards equivalent to Tier 1 emission standards starting with engine s manufactured on July 1, 2006. This means

115that prior to complying with Tier 3 emissi on standards, all emergency fire pump engines will have to meet currently achievable em ission standards. Regarding the comments pertaining to high speed emer gency fire pump engine, information available from the rulemaking docket (see Document ID Number EPA-HQ-OAR-2005-0029-0098) shows that at least one commenter (248) uses hi gh speed engines for certain emergency fire pump applications, and in fact, the commente r has indicated that it imports some engines from Italy for this purpose. While EPA believe s that it may be possible for all fire pump engines to not be high speed, EPA does not have sufficient evidence at this time to promulgate regulations based on this belief. EPA does not disagree that there may be high speed Tier 3 engines available, but these ar e not designed for fire pump applications. EPA believes it is appropriate to allow add itional time for high speed fire pump engines to reach compliance with Tier 3 emission st andards and feels the emission standards and compliance dates are appropriate as proposed.

14.2 Comment : One commenter (240) supported the two-prong approach proposed for fire pumps. The proposal recognizes that some fire pump engines are nonroad engines and others are specifically developed as fire pump engines. For those fire pump engines that are also nonroad engines, the maximum engine power is the power listed in the application for certification a nd the NFPA nameplate power is 10 percent less than the certified power. For those engines that have specifically developed fire pump ratings, the proposal calls for testing and certifying thes e engines to their NFPA nameplate power, while recognizing that the maximum power available during dynamometer testing is 10 percent higher than this power . The commenter agreed with this approach. To utilize

116this option, EPA proposes requiring that the engi ne manufacturer “certify that the engine will not be used in any application that allo ws higher hp and provided that the engine is not modified following testing.” Engine manuf acturers are not able to control how the engine is used; the manufacturer can only in form the customer on how the engine is intended to be used. Furthermore, the last part of the sentence in the proposal is not needed since the modification of the emissions characteristics of any certified engine, fire pump or not, is not allowed. Thus, the comm enter recommended that the last sentence of §60.4210(g) of the proposed rule be changed to read as follows: “Fire pump engines may

test at the NFPA cer tified nameplate hp, provided that th e engine is labeled as “Fire Pump Applications Only”.” This approach is similar to that used when an engine manufacturer certifies an engine for use as a constant speed engine using the D-2 test cycle.

Another commenter (248) expr essed that it disa greed with §60.4210(g) of the proposed rule. Manufacturers can only confirm the custom ers declared intended use for an engine. It is impossible for an engine manufacturer to control the use of engines after they have been sold, therefore impossibl e to certify such. The requi rement for this certification effectively leaves this test method unusable . The language here should be changed to “the engine manufacturer shall, as part of the emission label, restrict the use of the engine to fire pump application.” This correctly places the burden of conformance on the owners/operators.

117Response : EPA understands that engine manufactu rers are not able to control how the engine is used, but can only instruct the cu stomer of how the engine is intended to be used. EPA agrees that the last part of §60.4210(g) of the proposed rule, which states “and provided that the engine is not modified following testi ng,” is not needed since the modification of a certified engine is not allowed. EPA believes the suggestion that the commenters have provided regarding this sect ion of the rule is appropriate and has written the final rule to incorporate the comm enters’ suggestions. The last sentence of 60.4210(g) is written as “Fire pump engines ma y test at the Nati onal Fire Protection Association (NFPA) certified na meplate hp, provided that the engine is labeled as “Fire Pump Applications Only”.”

14.3 Comment : One commenter (245) supported EPA recognition of the unique aspects of fire pump engines and notes that fire pump engines are produced in very low volumes to provide vital life and property protection functions, and need greater lead time than other engines. The commenter supported th e following specific provisions as being necessary for fire pump engines:

a. A July 1, 2006 implementation date for the interim program, in which the owner/operator must demonstrate comp liance with the Tier 1 standards,

b. Implementation of the Tier 3 standards 3 y ears after the Tier 3 effective date for nonroad engines,

c. No requirements for aftertreatment (T ier 4 levels) on fire pump engines,

d. Provisions for certification of fire-pump-only engines at the NFPA nameplate power, and

118e. Optional testing of fire pump e ngines on a special test cycle. The commenter did not support th e requirement that fire pump engines be certified to Tier 1 levels starting on January 1, 2007. This will result in a significant cost to manufacturers, with very low sales volumes over which to recover those costs, and it will not result in any environmental benefit. So me fire pump engine ratings are unique and have not been previously certified. The ow ners/operators will have available emissions data demonstrating that the engines can meet Tier 1 (per the requirements of §§60.4200(b) and 60.4205(c) of the proposed rule). But it will be time consuming and expensive to actually certify th ese engines, according to the commenter. Furthermore, the fuel flow rate of some of these fire pum p engines is such that the fire pump rating would be the parent engine of the nonroad fam ily. This would lead to the need for a new certification test, adding to the cost. The commenter r ecommended that EPA modify table 2 of the proposed rule to delete the fi rst row of standards (t he Tier 1 standards) associated with each power category. The remaining row of the table (currently the second row) would then be the first (and onl y) standards to which fire pump engines would need to be certified. Section 60.4202(e) of the proposed rule should be similarly modified to read: “Stationary CI internal combustion engine manuf acturers must certify their fire pump stationary CI ICE to the emi ssion standards in table 2 of this subpart, for all pollutants, for the applicable MY and maximum engine power.”

One commenter (248) stated that regard ing §60.4202(e) of the proposed rule, which

contains the emission standards for fire pump engines, the commenter disagreed. Considering the very low contribution fire pump engines make to the pollution of the

119atmosphere there is no justification to burde n this industry and th e end user with the expense of dollars and utilization of personne l resources to certify engines that were already required to be compliant in § 60.4200 and 60.4200(b) of the proposed rule. The emission limits for this phase in some power categories are less than the Tier 1 of the offroad rule, in other power categories additional elements are being regulated relative to the

off-road rule. The commenter states that few if any of the old Tier 1 certifications would apply for this set of limitations. The firs t level of emission limitations for fire pump engines, for each power category as defined in table 2 of the proposed rule, should be enforceable via §60.4211(b)(3) of the proposed rule until that power category transitions

to the next lower set of emission limits. The commenter also suggests changing the word “certify” in Table 2, notes 1, 2 and 3 to “pro vide” in light of its comments regarding §60.4202(e).

One commenter (268) was in agreement with commenters 245 and 248’s opinion that certifying engines that have al ready been proven to be complia nt with Tier 1 standards is an unjustified expense as it will not result in any benef it to the environment. The commenter asked if the engines must meet Ti er 1 standards as of June 2006, what would be the purpose of having engine manufacturers bear the expense of certifying each engine in January of 2007.

One commenter (240) agreed with the proposal recognizing that additional leadtime is required for certification of fire pump engines. Fire pump engines must go through extensive extra safety testing and certification, so the additional 3 year leadtime is well

120reasoned and appropriate. The commenter stated that for fire pumps required to meet the Tier 1 standards, EPA should establish no cer tification requirements of any kind. Under the proposal, manufacturers are required to maintain data starting on July 1, 2006, showing that their fire pumps comply with Tier 1. Thereafter, as of January 1, 2007,

manufacturers would be required to “certify” their fire pumps to those same Tier 1 standards. There is no purpose that will be served by imposing this certification burden for such a limited number of engines when the relevant Tier 1 standards will not have changed. Instead, manufacturers should simply be held to the requirement that will take effect as of July 1, 2006. All that should be necessary is that ma nufacturers maintain sufficient data showing that their fire pumps comply with Tier 1 standards. Any requirements beyond that will only serve to engender burdens and costs without any corresponding environmental benefit.

Response : EPA acknowledges the commenters’ c oncerns on the issue of certifying emergency fire pump engines starting with th e 2007 MY. The majority of engines are already meeting Tier 1 levels; some are m eeting even more stringent levels. EPA understands that requiring certi fication so quickly for fire pump engines, which must go through more significant development and lead time, will be burdensome, especially given that owners and operator s will already be required to s how that these engines meet Tier 1 standards. EPA therefore agrees that manufacturers may star t certification to the

second row of standards in table 2 of the rule. However, EPA will need to keep all of the Tier 1 standards in Table 2, because owners and operators will st ill need to show compliance with such standards until certificatio n of such engines is required. Also, EPA

121will need to revise requirements for owners and operators of fire pump engines that are not certified beginning in MY 2007, in order to ensure that such owners and operators can show compliance with Tier 1 emission standards. Commenters 245 and 268 do not appear to object to the requi rement to certify engines once more stringent standards go

into effect. Commenter 248’s comments ar e unclear on this, but EPA believes that following the initial lead time provided for Tier 1 engines, there is no reason why engine manufacturers should be exempted from certifyi ng fire pump engines. The certification requirements are a key element of this rule and its effectiveness. EPA does not believe the certification of emergenc y fire pump engines to emission standards beyond Tier 1 will be a significant burden, and the comme nt provides no reason to exempt fire pump engine manufacturers from such requirement s. As EPA will continue to require certification of post-Tier 1 engi nes, it will not change the wo rd “certify” to “provide” in notes 1, 2, and 3 of Table 2.

14.4 Comment : One commenter (248) said that the regulation of emissions from emergency CI fire pumps is unwarranted in light of the very low population of these engines, and their continual inherent emi ssion reduction as derivatives of emission controlled engines results in insignificant ove rall emissions from these engines as a group. Thus, the low environmental benefits fr om regulation compared to the substantial costs for compliance and adverse impact on the reliability of such engines is unjustified. If EPA is going to regulate fire pump engi nes, the commenter asked that EPA not regulate them to emission limits lower than those proposed for MY 2007 in table 2 of the proposed rule, which are off-road limits. Th ese limits are achievable without extreme

122complexities being added to the engines, according to the commenter. The commenter also noted that emissions from its fire pump engines have already decreased in the last decade due to improvements in the emissions characteristics of the base engines upon which the fire pump engines are derived.

One commenter (268) wished to state that, in contrast to the comments of commenter 248, it is very much in favor of emission regula tion and is willing to do its part to help EPA achieve its goal.

Response : EPA generally disagrees with commente r 248. EPA is required to regulate all

sources under the NSPS and there is no t echnical reason why emergency fire pump engines should not be regulated. EPA does be lieve it is appropriate to exempt fire pump engines, and all emergency engines, from m eeting standards that re quire the use of addon controls, for reasons descri bed in the preamble to the rule. However, EPA does not see any reason why fire pump engines shoul d not be able to achieve the emission standards that do not rely on th e use of aftertreatment. Th e emission standards that EPA is requiring for emergency fire pump engines are appropriate and achi evable, and in fact, the commenter provided information to EPA which indicated that fire pump engines arecapable of meeting the limits imposed by EPA (see Document ID Number EPA-HQOAR-2005-0029-0109). Neither commenter 245 nor commenter 268, both of whom make fire pumps engines, provide any indica tion that these standards were problematic, especially given the requirement that all othe r CI engines used in the U.S. will by such date be required to meet t hose standards or more stringen t standards. As previously

123stated, special provisions have been provide d for emergency fire pump engines to allow for sufficient time for pump manufacturers to de sign and assemble units that comply with all relevant standards. Additionally, as stated, emergency fire pump engines are only subject to standards that do not require the use of aftertreat ment controls, and EPA is not aware of any technical reasons why these engi nes should not be able to comply with the

emission standards. See the comment and res ponse to 14.8 regarding the effect of these regulations on reliability of fire pumps.

14.5 Comment : One commenter (248) stated that the current language in §60.4202(e) of the proposed rule may be confused to in clude the 10 percent a dditional power fire engines have and requested that EPA re place “maximum” with “NFPA nameplate.” Prior to fire pump engines being emission ce rtified by the engine manufacturer as defined by the rule beginning in MY 2007, the commenter asked if the date that the engine is built into a certified NFPA fire pump engine be considered the date of manufacture. This will be necessary to process conforming e ngines manufactured before July, 1 2006 and NFPA certified after July 1, 2006. With the proposed date of MY 2007 for certified fire pump engines to be available from the engine manufacturers, fire pump engine certifiers, such as the commenter, will have a problem with carryover inventory that is compliant

but not certified. The commenter asked what language can be provided in the rule to allow for the sell out of 2006 compliant inventory in 2007.

Response : EPA agrees with the first comment regarding §60.4202(e) and believes that it is appropriate to replace “maximum” with “NFPA nameplate.” This change is reflected

124in the final rule. For emergency fire pump e ngines, the manufacturing date is the date the engine is built into a certified NFPA fire pump engine. EPA ha s clarified this in the final rule. As far as including addi tional special provisions for fire pump engine certifiers with respect to carryover inventory that meets the emission sta ndards but is not certified equipment, EPA worked with the commenter to arrive at an applicab ility date that would be workable. The applicability date of July 11, 2006, as specif ied in §60.4200, already accounts for this issue and fire pumps have been given more time than other engines.

The commenter has also been aware of this applicability date for some time and EPA does not expect there to be i ssues with existing inventory. Furthermore, as proposed, if the engines are pre-2007 MY engines, these en gines will not be requi red to be certified, but owners and operators of these engi nes can maintain information from the manufacturer, which shows that the engine m eets the emission standards. In the final rule, EPA has expanded this flexibility for all Tier 1 fire pump engines. For these reasons, EPA does not believe it is necessary to provide additional time, beyond the extra time provided, for sell out of existing fire pump engines.

14.6 Comment : One commenter (266) cited III.E.4 of the preamble to the proposed rule, which contains the requirements for owners/ operators of emergency fire pumps. The commenter stated that it should be specified that the manufacture rs should meet the emission standards and the owners/operators sh ould maintain the engines to ensure the

emission standards are met.

125Response : EPA regulations require owners and operators to be obligated to meet appropriate standards; howe ver, in the owner-operator compliance provisions of §60.4211(a) of the final rule, EPA specifies that owners and operators who must comply with emission standards must operate and main tain the stationary CI internal combustion engine and control device according to the manufacturer’s written instructions. This provision applies to all stationa ry engines subject to emissi on standards under this rule, including emergency fire pump engines. EP A requires that owners and operators of uncertified engines demonstrate compliance through methods such as keeping records from manufacturers or vendors showing co mpliance. EPA also requires in §60.4211(c) that owners and operators of 2007 MY and la ter engines must comply by purchasing an engine that is certified. EPA will be allo wing manufacturers of fire pumps engines to sell, and allowing owners and operators to buy, uncertified fire pump engines beyond the 2007 MY until standards more stringent than Tier 1 standards take effect.

14.7 Comment : One commenter (268) referred to correspondence between Sims Roy of EPA and John Whitney of Clarke Fire Prot ection Products on June 2, 2005, available from the rulemaking docket, where it is men tioned that emergency fire pump engines with a rated speed of greater than 2,650 rpm have an addition al 3 years to meet Tier 3 standards if a high speed engine that meets Tier 3 standards is not available for the MY.

The commenter asked if it can understand this to mean that if it manufactures emergency fire pump engines with an rpm of greater than 2,650 that do meet Tier 3 standards, the regulation would no longer allow the additional 3 years for the industry.

126Response : The emission standards for emergency fire pump engines ar e given in table 2 of the rule. Footnotes 1 through 3 allow certa in high speed fire pump engines to certify to less stringent emission standards for so me model years. This provision is not contingent upon high speed engine s that meet Tier 3 emission st andards being available.

14.8 Comment : One commenter (240) said that additional investigation may be

warranted to assess whether the stricter emi ssion standards to be imposed on fire pumps under the proposed NSPS (which will necessitate advanced electronic controls and other engine design changes) could adversely affect the reliability of fire-pump engines.

One commenter (248) said that regarding EP A’s request for comments on the impact on reliability of fire pump engines as a result of this proposed rule the commenter stated that it is impossible to quantify the reduction in reliability the additional complexities necessary to conform to the proposed emission limitations will cause. For sure, the most reliable system is the simplest system, and th ese new technologies are not simple. It does not surprise the commenter that not one engi ne manufacturer will go on record that it has doubts about the reliability of its future fire pump engines. That would be marketing suicide. The commenter’s experience with fire pump installers is that they will install the fire pump package presented to them, but the commenter did not beli eve they would have an understanding of technologies involved to achieve the emission reductions proposed.

127One commenter (268) wished to state that in its opinion, improving efficiency will increase reliability as cleaner and more complete combustion will produce less byproducts and deposits, increasi ng useful engine life.

Response : EPA does not believe additional inve stigation, as suggested by commenter 240, is necessary prior to completion of this rule. EPA stated in the preamble to the proposed rule that fire pump engine manufacturers and installers ha ve indicated that the provisions of the rule will not reduce the reliability of fi re pump engines. EPA also requested comment on this issue and it wa s one commenter’s opi nion that improving efficiency will increase reliability as cleaner and more complete combustion will produce less by-products and deposits, increasing usef ul engine life. EPA has provided fire pumps additional time to comply with the em ission standards and the extra time provided should be sufficient time for emergency fire pump manufacturers to resolve any issues there may be related to reliability. EPA ha s also exempted emergency fire pump engines from meeting Tier 4 emission standards that rely on the use of add-on controls. Finally, no information has been submitted to EPA indicating any reliability issues.

15.0 Prior Tier Certification Requirements

15.1 Comment : One commenter (240) stated that the rule should not impose any new type of certification requirements with respect to any Tier 1 standards. Since the Tier 1 standards are no longer “curren t” in the nonroad engine co ntext, nonroad engines are no longer capable of being “certif ied” to those Tier 1 sta ndards. The language of §§60.4201 and 60.4202 of the proposed rule should be revise d to delete any requi rement to “certify”

128engines to any expired nonroad engine st andards. Instead, a simple carry-over

mechanism should be established to address t hose stationary CI e ngines that will be manufactured to comply with the emission standards applicable to prior-Tier nonroad engines. In such cases, the commenter recommended that EPA issue one “master” certification form listing all of a given manufact urer’s stationary CI engine families and ratings that are carry-overs of previously-certified, prior-Tier nonroad engines. This type of mechanism would greatly simplify the “certification” process of prior-Tier engines, while also alleviating the workload that ot herwise would fall on EPA personnel (with no corresponding environmental benefit).

Response : EPA disagrees with the commenter. The certification procedures carried over from the mobile source regulations require that engine families be certified every year. This is necessary even with regard to engine families that are not subject to new, more stringent, standards. It is needed to ensu re that any changes in design to any engine family do not cause the engine family to exceed applicable standards. This is equally true for stationary engines. Regarding the desi re for a simplified carry-over mechanism for engines meeting previous tier standards, EP A’s regulations already contain simplified procedures for certifying engi ne families that have not changed appreciably from one year to the next and that are not subject to new standards. However, the commenter is incorrect to presume that merely because an engine family does not need to meet new standards, the engine will not change a ppreciably from year to year. Engine

manufacturers are often redesi gning engines and creating new engines to meet the needs of their customers, as well as regulatory requirements. EPA cannot merely assume that

129all such engines will meet existing standards. Nor can owners and operators of engines presume that such engines meet these emission requirements. Given that the structure of

this rule is intended to allow owners and operators to rely on the certificat ion of engines to avoid more onerous compliance requirement s, EPA believes that requiring certification of these engines is appropriate. Additionall y, with regard to meeting Tier 1 standards, the proposal only required fire pump engines and engines above 3,000 hp with displacement below 10 l/cyl to certify to Ti er 1 standards that no longer applied to nonroad engines. As discussed above in sec tion 14 of this document, in the final rule, EPA is not requiring certification for Tier 1 fire pump engines, due to particular issues concerning fire pumps. The commenter provides no evidence that certification of Tier 1 engines above 3,000 hp with displacement below 10 l/cyl is at all burdensome. On the other hand, the comment refers to emergency en gines that are not requ ired to meet final nonroad Tier 4 standards. For such engines, the last set of standa rds required under the rule (either Tier 2, 3 or interi m Tier 4 standards) are the fina l standards that these engines are required to meet into the future. Unless EPA promulgates more stringent standards in the future, these engines will be required to m eet these standards for many years to come. EPA cannot presume that merely because the engine emission standards are not changing, that the engines themselves will not cha nge. Therefore, it is critical for EPA to continue to require certification into the futu re for these engines. While the commenter refers to these standards as “prior-Tier” sta ndards, it is important to remember that such standards will be the currently-applicable st andards for these engines (which represent most of the diesel stationary engine population) and thus EPA must insure that such engines are meeting these standards.

13016.0 Emission Standards

16.1 Emergency Engines

16.1.1 Comment : One commenter (240) stated th at EPA’s treatment of emergency engines separately from non-emergency e ngines was necessary and appropriate. Emergency engines perform vital life-saving fu nctions when regular power supplies have been disrupted, and so must be configured in ways that do not je opardize their start-up capabilities and reliability. Emergency engi nes typically operate less than 50 hours per year, and so inherently have li ttle overall impact on air quality or emissions inventories.

Response : EPA agrees with the comment.

16.1.2 Comment : One commenter (240) believed th at interim Tier 4 NOx standards should not be applied to emergency engines, which will not be required to be equipped

with PM aftertreatment. Manufacturers c ould have to undertake separate and unique design and manufacturing effort s for emergency engines to meet Tier 4 NOx standards (with PM aftertreatment). That would be co st-prohibitive and unwor kable. The Tier 3 standards generally should be the final sta ndards for all emergency engines greater than or equal to 37 kW (50 hp). For engines le ss than 37 kW (50 hp), emergency engines can be required to meet the Tier 4 standards, si nce none of those standards will necessitate unique engine aftertreatment or design featur es for NOx. For emergency engines greater than or equal to 3,000 hp, the Tier 2 standards should be the final standards. Regarding

131specific emission standards, the commenter st ates that two need to be changed. For engines 19 to 36 kW (25 to 49 hp), the proposal would require that those engines meet the interim Tier 4 standard for PM, but the final Tier 4 standard for NOx. This would result in a hybrid engine that manufacturers are not slated to produce under the nonroad rule. Accordingly, the applicab le standards should be the inte rim (not the final) Tier 4 standards for PM and NOx (0.30 grams per kilowatt-hour (g/kW-hr) PM (0.22 g/hp-hr); 7.5 g/kW-hr (5.6 g/hp-hr)) for those engines. For engines 37 to 55 kW (50 to 74 hp), the proposal would require that manufacturers m eet the optional Tier 4 pull-ahead standard of 0.30 g/kW-hr (0.22 g/hp-hr) PM (which st andard was adopted to provide nonroad manufacturers with the option of deferring co mpliance with the final nonroad Tier 4 PM standard until 2013). Since the final nonr oad Tier 4 standards will not apply to emergency engines, the optional pull-ahead stan dard also should not apply. Instead, the Tier 3 PM standard of 0.40 g/kW-hr (0.30 g/ hp-hr) should be the final standard that applies to these engines.

Response : It is unclear exactly what the co mmenter means by “interim Tier 4 NOx standards.” EPA required Tier 4 standards (interim or final) only for emergency engines up to 56 kW (75 hp). No other emergency engine s are required to be ce rtified to any Tier 4 standards. The commenter appears to agree with EPA’s view that Tier 4 standards that do not require aftertreatment are appropriate for emergency engines, but appears to want to prevent needing to design emergency engine s to meet unique standards. For engines rated below 19 kW, the commenter appear s to have no objection to the proposed standards. For engines rated at 19 and be low 37 kW, the commenter does not object to

132EPA’s proposed standard from 2008-2014, whic h would incorporate the interim Tier 4 standards, but objects to th e incorporation of the final NOx (actually NOx + NMHC) standards for these engines because it creates a hybrid set of engine standards that does not correspond with any engine standards for nonroad engines. EPA agrees that it is inappropriate to require a unique set of standards for these engines and has not incorporated the final Tier 4 NOx standard for these engines into the final rule. Regarding engines rated at 37 to 55 kW, EPA agrees that as no nonroad engines were required to meet the optional interim Tier 4 PM standard, it is approp riate not to require emergency engines to be certified to such standards. Regarding engines equal to or greater than 3,000 hp, EPA agrees th at the final standards should be the Tier 2 standards, and EPA proposed this. However, EPA unders tands that the regulatory language may not have been clear regarding these standards, and EPA explicitly refers to Tier 2 standards for these engines in the fi nal regulatory language.

16.1.3 Comment : One commenter (264) agreed with EPA that emergency engines should not require the installation of aftertreatment technologies. Tier 3 standards should be the final tier of emission standards for emergency applications.

Response : See Response to 16.1.2.

16.1.4 Comment : One commenter (243) expressed that EPA’s proposal to exempt “emergency” engines from Tier 4-equivalent standards is unjustifiable, given the tremendous health benefits associated with reducing diesel exhaust emissions, and is

133unlawful. The commenter states that even gi ven the poorer cost-effectiveness of controls on these engines, the benefits expected from the controls under the cost-benefit analysis would still outweigh the costs. The commente r also notes that having different standards for emergency and non-emergency engines can create an incentive for consumers to choose to buy an emergency engine even if it will be used for non-emergency purposes. The commenter claims that failure to require Ti er 4 controls on all new stationary engines

violates tenets of administrative law and reasoned decision making.

Response : EPA disagrees with this comment and believes it is appropriate and justified to regulate stationary CI em ergency engines to emission stan dards that do not require the use of aftertreatment controls. This appr oach is consistent with other rulemaking decisions EPA has made in the past for stationary engines, which ha ve not required that emergency engines be equipped with add-on controls. Stationary emergency engines are infrequently used and their primary purpos e is to support equipment during emergency

situations. Commenter 240 estimates use of emergency engines at approximately 50 hours per year. As documented in informa tion submitted to the docket for the proposal (EPA-HQ-OAR-2005-0029-0011), emergency engines are operated infrequently and EPA would agree that 50 hours per year is representative of emergency engine operation. A study conducted by the CA ARB in 2002 indica ted that emergency CI engines operate on average about 30 hours per year. The aver age includes hours spent in emergency and non-emergency service. EPA considered co sts, as required by section 111, when evaluating BDT for stationary CI emergency engines and determined that the cost of CDPF, NOx adsorber, and oxidati on catalysts, the main tec hnologies expected to reduce

134emissions to comply with Tier 4 emission st andards, was extremely high compared to the amount of pollutant potentially reduced from emergency engines through the application of aftertreatment controls. The cost per t on of emission levels that would result from requiring aftertreatment are well above normal regulatory cost per ton levels. EPA agrees there can be significant health benefits in reducing emissions from emergency engines, and EPA has promulgated standards that wi ll reduce such emissions. However, EPA believes that the increased upfront costs of e ngines with aftertreatme nt are not justified for these engines, which are used so rarely a nd often in situations where greater and more immediate harm to human health (e .g., fire or flood) is evident. In addition, EPA does not wish to prevent owners from being able to purchase new emergency engines. Given that emergency engines with aftertreatment will be appreciably more expensive than engines without aftertreatment , EPA believes that substantial increases in cost may dissuade owners and operators from purchas ing new emergency engines which, given the importance of these engines, may be counterpr oductive to the goal of better human health and welfare. In addition, because these engines are used infrequently and in limited operations, the exhaust temperatures of these engines when they are in use are not wellsuited for aftertreatment technologies. For th ese reasons, EPA believes it is justified in promulgating standards for stationary CI emer gency engines that do not require the use of

aftertreatment controls. As discussed else where, EPA is finalizing several enforcement provisions that will substantially deter cons umers from violating the provisions of the rule. Further, the CAA provides for substant ial penalties for viola tion of the NSPS.

13516.1.5 Comment : One commenter (266) said that it appears that the rule did not anticipate a common type of ope ration of a stationary engine generator; the occasional use to provide back-up power to critical operations during si te or facility interruptions, and maintaining and testing of the integrity of the equipm ent supporting a site’s power. While these requirements may be met with a port able generator, it is often safer to use an installed permanent generator for this purpose. This generator is also used to provide power for emergency purposes as outlined in this proposal. The commenter recommended that the rule replace all refere nces to “emergency generator” with “noncontinuously operating generator” to appropriately specify th e rule’s application. These generators provide standby power and are ope rated less than 10 percent of the operating time for the equipment supported. In addition to the emergency purposes described in the proposal, these generators are us ed for periodic site or faci lity interruptions, and testing and maintenance of electrical power systems. All of which, ensures safe operation of the commenter’s operations. These generators s hould meet Tier 1 standards as shown in table 2 of the proposed rule.

Response : As defined in the proposal, an em ergency engine is an engine whose operation is limited to emergency situations a nd required testing. Stat ionary engines used to produce power for critical networks when electric power from the local utility is interrupted would be considered emergency engines. EPA believes that the way it has defined an emergency engine in the propos al is appropriate, but has made slight

modifications to the definition. After “loc al utility,” EPA has added “(or the normal power source, if the facility runs on its own power production)” and has also clarified that

136peak shaving is not considered emergency use. EPA has also added “and maintenance”

to the first sentence of the definition. Othe rwise, the definition remains as proposed, in the final rule. The use of emergency e ngines for other purposes besides emergency operation and required maintenance and testi ng, e.g., such as peak shaving or general maintenance of a facility, is not permitted. The commenter did not provide any justification for why emergency engines should be regulated to Tier 1 emission standards. EPA is already providing flexibility for emer gency engines in that these engines do not

have to meet Tier 4 emission standards that rely on the use of aftertreatment controls. EPA does not see why emergency engines shoul d only be regulated to Tier 1 emission standards when these engines are fully capab le of achieving higher Tier limits.

13716.2 Engines >750 hp

16.2.1 Comment : One commenter (240) stated that as was the case with the nonroad engines from which stationary CI engines are derived, it remains the case that less stringent standards are necessary for non-generator engines greater than 750 hp.

One commenter (243) said that EPA should se t stringent NOx emissions standards for all engines greater than 750 hp that are based on the use of add-on cont rol technologies. The commenter estimated that stationary diesel engines greater than 750 hp make up about 20 percent of the total stationary engine population, but account for more than half the total

emissions of NOx. The commenter has seen enough successful examples of the use of SCR to control NOx emissions from stationary engines to conclude that EPA should base its NOx emissions standards for these engines on the use of add-on controls. EPA

describes in docket informati on that SCR has been successf ully installed in several applications based on State and vendor in formation. Several additional add-on NOx controls that are under development are descri bed in the docket as well; NOx adsorbers, ozone injection and lean NOx catalysts. While these technologies are not commercially available yet, they could become viable options within the timeframe of these standards.

The commenter believed the current use of S CR and the other available options for addon NOx control support the more stringent sta ndards. The commenter is not aware of any special issues with add-on controls on non

- generator stationary engines. The commenter

believed the issues would be no different than those associated with stationary generator sets and, therefore, saw no reason to set more lenient standards.

138One commenter (244) believed th at NOx standards for non-gene rator, stationary engines with hp ratings of greater th an 750 should be equivalent to NOx standards proposed for generators. Selective catalytic reducti on systems have already been installed on stationary engines in this si ze range and can provide high e fficiency NOx reductions in a

cost effective manner. The commenter believ ed that installation issues with SCR on nongenerator engines are no different than t hose associated with generator engines

.

One commenter (238) strongly urged EPA to set aftertreatment forcing NOx standards for all non-emergency engines with a displacem ent of less than 10 l/cyl and greater than 750 hp. The rationale for setti ng less stringent standards fo r nonroad engines other than generator sets were concerns about designi ng NOx adsorbers for the space constraints and physical stresses associated with mobile heavy equipment. These conditions do not apply to stationary engines. In the Ju ly 2004 nonroad rulemaking, EPA noted the use of SCR on stationary engines as a rationale fo r aftertreatment forcing NOx standards for mobile generator set engines.

Regarding EPA’s request for comments on whether the generator standards for NOx should be applied for non-emergency engine s greater than 750 hp, one commenter (265) believed that the non-emergency generator engines should be limited to the same levels of emissions as other available ways to ge nerate electricity from fossil fuel. The commenter recommended that limits for engine s greater than 750 hp be as stringent as limits for non-emergency engines in sizes between 75 hp and 750 hp, because the larger

139engines should be able to achieve the same limit as smaller engines, and there is sufficient time to transfer technology to engi nes greater than 750 hp. If a large engine cannot achieve comparable emission levels, th en cleaner equipment, such as turbines,

should be used.

Two commenters (266, 267) made the comment that the requirement for add-on controls for engines above 750 hp with a displacement below 10 l/cyl should apply solely to continuously operating non-emergency generators.

Response : EPA proposed emission standards fo r non-emergency non-generators above 750 hp that were not based on the use of add-on controls for NOx and were less stringent than the proposed standards for generator sets above 750 hp. These standards were

consistent with nonroad standards for the sa me size engines. EPA solicited comments on this issue in the preamble to the proposed ru le and received the comments as summarized

above. Based on available information and co mments received on this issue, EPA still believes it is appropriate to distinguish between non-generators and generators when finalizing standards for non-emergency stati onary CI engines above 750 hp. EPA did not receive any specific information or data dem onstrating that the sta ndards applicable to generator sets are feasible for engines above 750 hp that are not generator sets. Engine manufacturers have repeatedly expressed that less stringent standards are necessary for non-generator set engines greater than 750 hp. Engine manufacturers have also repeatedly expressed the need to have standard s for stationary engine s that are consistent with the standards for nonroad engines. No change has been made to the final rule,

140which includes, as proposed, emission standard s consistent with nonr oad standards. The standards distinguish between non-generator sets and generator sets, and require less stringent levels for non-emergency engines th at are not generator sets, based on improved combustion systems and engine-based NOx contro l technologies. (It should be noted that the PM standards for engines above 750 hp, both for generators and non-generators, will likely require particulate traps.)

16.3 Engines <75 hp

16.3.1 Comment : One commenter (244) supported EP A position that the results of the planned 2007 nonroad diesel engine technology review focused on smaller diesel engines (less than 75 hp) should apply to stationary diesel engines as well. The commenter believed some very promising technologies are emerging that could be applied to smaller nonroad and stationary diesel engines to provide meaningful PM, NMHC, and NOx

emission reductions at a reas onable cost with good performance. These technologies include such concepts as “ope n” DPF and lean NOx catalyst.

Response : No response is needed.

16.4 Engines with a Displacement of <30 Liters per Cylinder

16.4.1 Comment : One commenter (226) stated that it is unclear why engines with a displacement of greater than or equal to 10 l/cyl should have differe nt emission standards than those with a displacement of less 10 l/cyl if they are both bei ng used for stationary

141service. The commenter suggested that the re gulation be strictly ba sed on engine power

output.

Response : EPA explained in the preamble to the proposed rule and in supporting documentation included in the rulemaking doc ket why it is appropriate to establish different emission standards for stationary CI engines with a displacem ent of greater than or equal to 10 l/cyl. Accord ing to engine manufacturers, stationary CI engines with a displacement between 10 and 30 l/cyl are not generally used in land-based nonroad applications, but are more similar to engines used in marine applications. Additionally, stationary CI engines with this displacement are operated differently than nonroad engines. Furthermore, EMA members do not produce any stationary CI engines with a displacement of greater than or equal to 10 l/cyl that are certif ied to the nonroad standards. For these reasons, it is appropriate to regulate stationary CI engines with a displacement between 10 and 30 l/cyl to the em ission standards for mari ne CI engines, as proposed, instead of to nonroad standards. To be consistent with the marine standards, stationary CI engines cannot be regulated strictly based on engine power, but must be regulated according to engine size as well as cylinder displacement.

For stationary CI engines with a displacement of greater than or equal to 30 l/cyl, EPA has been told that these engines are very different from nonroad e ngines and it would not be feasible to control these engines to nonroad certification standards. EPA has explained in supporting documentation to the proposed rule that these engines cannot apply the same control technologies as nonroad engines due to their large size and fuel

142used. These engines also ha ve vastly different operati ng characteristics that support requiring different emission standards and different compliance strategies for these engines. For these reasons, EPA feels it is justified in requir ing different emission standards than for other engines, and a displ acement cutoff, rather than an engine size cutoff, is appropriate to distinguish these unique engines from othe r engines regulated by

this rule.

16.4.2 Comment : One commenter (244) supported EPA position that a review of proposed standards for stationary diesel en gines with a displacement between 10 and 30 l/cyl should be done once EPA promulgates ne w emission standards for diesel marine engines, including diesel marine engines in this displacement range. The commenter

believed that exhaust emission control techno logies targeted for use to comply with

EPA’s Tier 4 nonroad diesel en gine program have applicabil ity on marine and stationary diesel engines in this size range.

Response : No response is needed.

16.5 Engines with a Displacement of ≥ 30 Liters per Cylinder

16.5.1 Comment : One commenter (234) said that th e NOx standards for engines with a displacement of greater than or equal to 30 l/cyl would incur si gnificant costs for the owner and operator, and for emergency engine s make it impossible to operate the unit reliably when actually needed. If readine ss testing is limited to 2.5 hours per month for

143emergency engines, entire subsystems supporti ng air pollution cont rol equipment could

themselves become unreliable. The cost of installing and maintaining an SCR system for large CI engines is outrageously high, esp ecially for applications in Alaska. These control systems are only marginally cost effec tive for Alaska units that are meant to be operated continuously. The cost of SCR c ontrols for emergency units outweighs the benefit of having large reliable emergency power available. A recent prevention of significant deterioration projec t rejected SCR due to high costs. Selective catalytic reduction subsystems must be kept instantl y ready over a long period of time in standby mode. One important aspect is having the ur ea/water mixture heated to prevent freeze up during extremely low temperatures. The syst em is not simple and operators/mechanics have to be well trained. In most areas of Alaska, such skilled labor is not available. Unless such large units are simple to main tain/operate, they will quickly fall into disrepair or become unusable in an emergency. For emergency engines, the technology that is proven to have the highest reliability while in standby mode should be used. Fuel Injection Timing Retard (FITR) is the technology. It redu ces NOx by 15 to 20 percent,

and has been demonstrated as the most co st effective for arctic conditions. This technology (FITR) should also be allowed for e ngines with a displacement of greater than 10 l/cyl unless/until manufacturers establish a proven record of reliable readiness from cold start conditions. This may require dela y of emission control requirements for an additional 3 years beyond current implementation dates.

This commenter also said that the PM limits in the proposed rule for engines with a displacement of greater than or equal to 30 l/cyl are unrealistic, a nd there are no current

144control technologies that are “available 11 ” to meet these standards. There have been no applications of ESP to stationary so urces in the U.S. to date (based on RACT/BACT/LAER Clearinghouse, Septem ber 1, 2005). A currently available technology, particulate filter trap s, is suited to these large units, although PM removal is less than 60 percent. The commenter noted that PM emissions will already be reduced considerably by the use LSD and ULSD. When the reduction from using low sulfur fuel is considered, an additional 50 percent overa ll reduction from partic ulate trap technology will meet EPA’s goal of reducing PM emissi ons nationwide. Requiring the use of ESP for emergency units undermines unit reliability and would increase unit size. Approximately 10 percent of the power gene rated by an emergency CI ICE would be used solely to power an ESP. This would cau se all such emergency un its to be resized at an increased capacity. The commenter reco mmended a 50 percent PM reduction or an emission limit of 0.15 g/kW-hr (0.113 g/hp-hr).

Response : EPA does not agree with the commenter that SCR control systems are not a feasible option for engines locate d in Alaska. There are at least three facilities in Alaska that have stationary engines equipped with SCR, see the memorandum entitled “Emission Standards for Engines with a Displacement of ≥ 30 Liters per Cylinder,” available from the rulemaking docket. EPA does not expect that there will be any emergency engines with a displacement greater than 30 l/cyl; howev er, to the extent that such units exist, they will be very substantial emitters duri ng use and should be required to use the best technology available. In response to the commenter’s statement regarding readiness testing, EPA has increased the maintenance a nd testing allowance for emergency engines

11 “Available” as used here has a meaning consistent with EPA’s “Top-Down” BACT analysis method.

145from 30 to 100 hours per year in the final ru le, with the option to submit a petition for additional hours. EPA agrees in genera l with the comments regarding the proposed

emission limitation for PM. The final rule has been written considering the comments received and requires 60 percent PM reduc tion or an emission limit of 0.15 g/KW-hr (0.11 g/hp-hr). EPA believes the PM standard will be achievable through the use of lower sulfur fuel, on-engine controls, and aftertreatment. EPA believes that the PM percent reduction requi rement is feasible through a pplication of ESP. Based on information EPA has received, the technology is capable of reducing PM by 60 percent.

Other information indicates that the technol ogy could reduce PM by even more; from 55 to 85 percent when operating on heavy fuel oil, see information in the docket. For further discussion regarding EPA’s final standards fo r engines with a disp lacement greater than 30 l/cyl, see the memorandum entitled “E mission Standards for Engines with a Displacement of ≥ 30 Liters per Cylinder.

16.5.2 Comment : One commenter (235) provided several comments on the proposed standards for engines with a displacement of greater than or equal to 30 l/cyl. The proposal states on page 39870 that “The intended effect of the standa rds is to require all new, modified and reconstructe d stationary CI ICE to use th e best demonstrated system of continuous emission reduction, consider ing costs, non-air quality health, and environmental and energy impacts, not just with add-on controls, but also by eliminating or reducing the formation of these pollutant s.” With respect to the emission limits proposed for engines with a displacement of greater than or equal to 30 l/cyl the commenter claims that the above principles have not been followed. The commenter

146stated that environmental impacts and cost e ffects have not been evaluated and efficient add-on abatement techniques (SCR for NOx, etc.) will always be needed as a result of the proposal. Only a small number of large CI ICE are sold per y ear to the U.S., and therefore, one can forecast that the environmen tal impact of these engines with respect to

the total emissions in the U.S. is small. Therefore, the proposed strict standards cannot be justified based on the air quality need. EPA states on page 39890 of the preamble to the proposed rule that it does not expect ther e to be any engines with a displacement of greater than or equal to 30 l/cyl. In U.S. te rritories there are severa l of these engines, e.g.,

in Puerto Rico there is a 20 MW electric (MWe) plant and in Guam there is an 80 MWe plant, the commenter said. The proposed lim its will raise the elec tricity produced in these power plants considerably. This mi ght have impacts on the small governmental jurisdiction area flexibility and have significant adverse affect on the supply of energy.

This would be in contradiction to the Re gulatory Flexibility Act and Executive Order 13211: Actions Concerning Regulations th at Significantly Affect Energy Supply,

Distribution or Use.

The commenter further stated th at costs and environmental quality need to be considered

in order for the rule to be consistent w ith the BDT principle, now only the lowest achievable emission rate (LAER) principle is being applied. In the U.S., LAER (cost aspect is not considered) is applied in non-at tainment areas only. No separate limits are proposed for large pre-2007 engines as for the smaller displacement categories. Existing pre-2007 large engines need to be regulated with their own separa te emission limits.

147The commenter added that the proposed NOx limit is very strict. The proposed limit of 0.4 g/kW-hr (0.30 g/hp-hr) equates to about 50 mg/Nm 3 (at 15 percent O 2 ). This limit is

much stricter than World Bank Guidelines or the United Kingdom (UK) limits as referred to in the proposed text. The World Bank NOx limit for non degraded air-sheds is 2,000 mg/Nm 3 and in degraded air-sheds 400 mg/ Nm 3 (at 15 percent O 2 ) (about 3.1 g/kW-hr). In the UK, the NOx limits are: 1,300/1,400 mg/Nm 3 (at 15 percent O 2 ) (about 10.1/10.9 g/kW-hr) (light fuel/heavy fuel oils) fo r plants less than 50 MW and 200-300 mg/Nm 3 (at 15 percent O 2 ) (about 1.6-2.3 g/kW-hr) for oil fire d plants greater than 50 MW. Extensive research and development work with NOx emissions from large liquid fired CI ICE has reduced emissions remarkably by prim ary measures (typically 30 to 35 percent) during the last decade. Primary met hods are low NOx combustion focusing on optimizing: closing timing of inlet valve, design of fuel injection equipment on the engine, new camshaft, etc. The proposed limit means in practice that SCR is always needed. Selective catalytic reduction n eeds a reagent aqueous urea/ammonia or pure ammonia to work, and lack of the reagent de livery infrastructure in certain areas will make the proper use of SCR impossible. In orde r to give industry an incentive to develop new cost-effective primary methods and to con tinue the positive development in the past decade, the proposed limit should be more realistic based on the zoning approach (attainment/non-attainment area, mainland U.S./other areas).

This commenter made some recommendations for acceptable emission limits. The commenter recommended for pre-2007 units limits according to World Bank. For 2007

and later for mainland U.S:

148Attainment areas : <50 MW plants in urban areas: 750 mg/Nm 3 (at 15 percent O 2 ) (about 5.8 g/kW-hr) <50 MW plants in other areas: 1,600 mg/ Nm 3 (at 15 percent O 2 ) (about 12.4 g/kW-hr)

≥ 50 MW plants: 750 mg/Nm 3 (at 15 percent O 2 ) (about 5.8 g/kW-hr) with emission correction for highly efficient engines, see EUROMOT document. 12

Non-attainment areas As in proposal.

For 2007 and later for U.S. territories: Guam, American Samoa or the Commonwealth of the Northern Mariana Islands, the limits according to EUROMOT paper. 13 The commenter stated that the proposed PM lim it of 0.12 g/kW-hr (0.09 g/hp-hr) equals about 16 mg/Nm 3 (at 15 percent O 2 ). This is a very strict limit, much stricter than the British and World Bank limits, which are 50 mg/Nm 3 (at 15 percent O 2 ) (about 0.38 g/kW-hr) for large CI plants and 100 mg/Nm 3 (at 15 percent O 2 ) (about 0.75 g/kW-hr) for smaller CI plants. The ESP is bulky and has a high investment cost. In the BREF document 14 for large combustion installations, it states th at “Due to the different temperature and O 2 content of the diesel flue-gas , the electrical properties of the diesel particulates (e.g., resistivity, etc.,) are different compared to particulates fr om a boiler flue-gas, and proper testing of the ESP (electrical precipitator) is needed to commercial release.” Only a few

12 www.euromot.org/dowload/news/positions/stationary/EIPPCB_BREF_back_up_document_euromot_com ments_jun03_table_6_41.pdf

. 13 Stationary Engine Emission Legislation – Diesel and Gas, the Euromot Position. November 2004. www.euromot.org/dowload/news/po sitions/stationary/Future_stati onary_engine_emission_legislation_Nov 04.pdf

. 14 Integrated Pollution Prevention and Control (IPCC), Reference Document on Best Available Techniques for Large Combustion Plants. May 2005. European IPCC Bureau. ftp://ftp.jrc.es/pub/eippcb/doc/lcp_final_0505.pdf

.

149CI plants are equipped with ESP, and the te chnical availability of ESP needs to be evaluated case-by-case. In the European In tegrated Pollution Prevention and Control, the best available technique is considered to be the use of low ash and low sulfur fuel. Particulate matter limits range from 30 to 50 mg/Nm 3 (at 15 percent O 2 ) (about 0.23 to 0.38 g/kW-hr) depending on whether heavy or li ght fuel oil is used. The commenter recommended PM limits in line with the EU BREF document for large CI ICE plant stations (greater than 50 MW ). For smaller CI ICE plants, the commenter recommended a PM limit according to the UK approach.

Response : EPA does not agree with the commenter that EPA did not evaluate costs and environmental impacts. EPA has provided detail ed analyses of the expected costs of this regulation and the expected emission re ductions and benefits and evaluated the technology for this rule based on best dem onstrated technology, not lowest achievable

emission rate. EPA evaluated the environm ental and economic impacts of the best demonstrated control technologies, which ar e documented in a memorandum included in the docket entitled “Emission Standards for Engines with a Displacement of ≥ 30 Liters per Cylinder.” While there are few CI ICE w ith a displacement of greater than or equal to 30 l/cyl, they are individually very la rge emitters of pollutants. Moreover, in regulating criteria pollutants su ch as ozone and PM, it is assumed that the emissions

come from numerous different sources whos e individual contribution may be relatively small. Further, as noted in the analyses, there are benefits from these standards in attainment areas, and these national regulations are designed to provide protection from pollution occurring in all areas of the country, not merely nonattainment areas. EPA does

150not believe that the final emission standards wi ll have a significant adverse effect on the price of electricity and the s upply of energy, and the commente rs did not provide any data to support this assertion. While EPA disagrees with much of the comm enter’s statements, EPA has evaluated all comments received on this matter and agrees with the comments that the proposed NOx g/KW-hr emission limitation and the proposed PM emission standards were too stringent. The final rule requires engines with a disp lacement greater than 30 l/cyl to reduce NOx emissions by at least 90 percent or meet a NOx emission limitation of 1.6 g/KW-hr (1.2 g/hp-hr), and to reduce PM emissions by at least 60 percent or meet a PM emission limitation of 0.15 g/KW-hr (0.11 g/hp-hr). There are several facilities worldwide that are successfully using ESP for PM control. For ex ample, a power plant in Korea is equipped with SCR and ESP and is limited to PM emissions of 30 mg/Sm 3 at 4 percent O 2 (about 0.06 g/HP-hr) (see rulemaking docket). Also, there is a power plant in Guam operating with ESP achieving less than 60 mg/Nm 3 at 15 percent O 2 (about 0.3 g/HP-hr) when operating on high sulfur fuel. Sources can al so use other approaches , including traps, the use of lower sulfur fuel, and on-engine cont rols. The PM emissi on limit is consistent

with comments received from commen ter 234. See Comment and Response 16.5.1. Regarding the NOx standard, SCR has been dem onstrated as feasible for stationary CI ICE and is in use on several engines in the U. S. As discussed above in the response to comment 8.2, SCR has achieved em ission reductions of 90 per cent or greater in many

cases. EPA reviewed emission rates of statio nary CI engines with a displacement of greater than or equal to 30 l/cyl and based on an average uncontrolled NOx emission rate from these engines of about 11.8 g/HP-hr, a pplying SCR with a reduction efficiency of

15190 percent yields a controlled NOx emission rate of 1.2 g/HP-hr. EPA therefore believes the final standards for NOx are appropriate. Also note, that the commenter seems to concede that these standards are feasible, because the commenter accepts the proposed (more stringent) standards in nonattainment areas. EPA notes that this regulation applies only to new engines, not existing engines. The only engines manufactured prior to April 1, 2006 covered by this regulation are engines that are modified or reconstructed, as is required under the CAA. Further information regarding how EPA established the final em ission reduction and limitation requirements

is discussed in a memorandum included in the docket entitled “Emission Standards for Engines with a Displacement of ≥ 30 Liters per Cylinder.”

16.5.3 Comment : One commenter (243) said that EPA must require stringent PM emissions limits for engines with a displacem ent of greater than or equal to 30 l/cyl. Particulate matter emissions from stationary di esel engines are associated with extremely serious health impacts, including premature mortality and cancer. It would be clearly arbitrary and capricious for EPA to exempt th e very largest engines, which it recognizes as operating for thousands of hours per year, fr om protective control requirements for PM

emissions. EPA is correct in its assessm ent that the cost of SCR to reduce NOx emissions from these engines is justified because they are so large and because the cost of SCR would be manageable in comparison to the cost of the engines themselves. Similarly, the size of these engines and the hazard posed by their emissions compels EPA to require them to achieve PM reductions that are at least as prot ective, if not greater than, those for smaller engines. EPA’s proposal for these very large engines fails to meet

152the most basic requirement of section 111 of the CAA, that stringent emissions standards be applied to all sources within the designated category. There is no evidence that a thorough technical analysis of cost or feasibil ity was performed for these large engines. EPA does not explain why particulate filters could not be developed to apply to these engines. Nor does it explain why ESP, th e technology on which the 60 percent control requirement is based, could not be designed to work as effectively in this application as they are known to do in many others, and achie ve reductions far in excess of 60 percent. The commenter urged EPA to remedy this de ficiency in the final rule by promulgating more stringent control requirements for this class of very large, very highly polluting engines.

Response : EPA disagrees with the commenter and believes that the emission standards promulgated for engines with a displacem ent greater than 30 l/cyl represent the application of the best demonstrated contro l technology for these engines. The emission standards being finalized were discussed in response to comment 16.5.2. An analysis of the cost and feasibility of emission contro ls was performed and can be found in the rulemaking docket in the memorandum entitled “Emission Standards for Engines with a Displacement of ≥ 30 Liters per Cylinder”. There is not hing in the final rule that would preclude the use of particulate filters for these large engines; however, EPA could not find any examples of the use of particulate filters on these engines and therefore could

not base the emission standards on the use of particulate filt ers. EPA feels that it has promulgated the most stringent control requ irements based on the best demonstrated technology for these large engi nes that can be achieved considering the technical

153feasibility and capability of aftertreatment controls and fuels used in these large displacement engines.

16.5.4 Comment : One commenter (266) commente r cited section III.E.3.b of the preamble to the proposed rule, which contains the proposed standards for owners/operators of engines with a displacemen t of greater than or equal to 30 l/cyl. The commenter stated that this requirement should not include non- continuously operating engines for standby power.

Response : EPA disagrees with the commenter that emission standards for engines with a displacement of greater than or equal to 30 l/cyl should not appl y to non-continuously operating engines. The commenter did not pr ovide any rationale supporting this position.

In the absence of a technical justification for why emergency engines should be exempted from the emission standards, EPA cannot fully ev aluate the merits of this comment. Due to the magnitude of emissions from engines w ith a displacement of gr eater than or equal to 30 l/cyl, EPA feels it is appropriate to require the same emission standards for emergency and non-emergency stationary engines of this displacement.

17.0 Peak Shaving

17.1 Comment : One commenter (242) stated the propos ed rule is cost prohibitive with

little environmental benefit fo r peak shaving facilities wi th low operating hours. The BDT for non-emergency engines was based on a cost per ton of pollutant removed calculated using 1,000 hours per year. The co st per ton of pollutant removed for the

154commenter ’s peak shaving engines with operating hour limitations is closer to the amount calculated for emergency engines than for prime engines. The commenter asked that EPA add a provision that non-emergency engi nes that limit their operation to up to 150 hours per year in a federally enforceable air permit, be allowed to meet the same standards as emergency generators.

Response : EPA does not agree that non-emerge ncy engines that operate 150 hours per year or less should meet the same emissi on standards as emergency engines. The commenter did not provide any supporting rationale or data suggesting that nonemergency engines operating up to 150 hours pe r year are unable to be equipped with aftertreatment controls and cap able of meeting Tier 4 emi ssion standards that require these add-on controls. Costs are not esp ecially high for these engines compared to benefits achieved. More importantly, the abil ity of an engine to run for peak shaving purposes will be based on the economic effectiveness of using such power for that purpose. If it is cost effective to use such engines for economic gain for such purposes, it will be used, but air quality should not be co mpromised for an essentially profit-based decision. Although the cost per ton of pollu tant removed, not including economic gain from operating the engine, may be similar to that of emergency engines, the decision to run an engine for peak shaving purposes is based on economic factors such as generated revenue. An emergency engine is entirely di fferent in that the decision to run such engine is not revenue based, but is the result of an unplanned, emergency event, necessitating the operation of the engine for inst ances where life safety may be an issue. Operating the engine for peak shaving purposes is a relatively planned activity, unlike

155emergency engines, which are used for unfores een emergency situations such as fires and natural disasters. Peak shaving involves income generation, which is not an emergency activity.

Engines that are used for peak shaving ar e not emergency engines and should not be exempt from meeting the more stringentemission standards applicable for nonemergency engines. This is consistent with previous regulatory d ecisions EPA has made and is also in line with how States treat peak shaving engines, e.g., the State of New York (commenter 238) agrees that peak shaving is not emer gency use. The CA ARB distributed generation rule re quires that sources apply the best technology available, a requirement that applies to non-emergency a nd peak shaving engines. Based on other comments received, EPA has added to the definition of emergency stationary internal combustion engine that peak shaving is not considered emergency use. EPA does not agree with the commenter and for the reasons provided in this response, EPA is not allowing peak shaving engines to meet the sa me standards as emergency engines. Peak shaving engines are considered non-emergency engines and must meet the applicable standards required for those engine s. EPA has clarified in the final rule that stationary CI ICE used to supply power to an electric grid or that supplies power as part of a financial arrangement with another entity are no t considered to be emergency engines.

15618.0 Need for Regulation

18.1 Comment : Two commenters (259, 260) stated that stationary CI engine emissions are already adequately addressed through fu el quality regulations and 40 CFR part 63, subpart ZZZZ for stationary RICE. The ru le would add another degree of regulatory complexity and more complicated compliance determinations, according to these

commenters. Commenter 259 said that it is unclear if EPA has reconciled the impacts or considered the compliance complexity associ ated with these layered regulations. EPA has not established the regulatory hierarchy or provided a mechanism for eliminating the overlapping and redundant regulatory requireme nts. Commenter 259 requested that the

hierarchal structure be defined in adva nce that includes a thorough review of each regulation potentially impacting this sour ce group thus eliminating confusion and ensuring consistency.

Response : EPA does not agree with the commenters’ statement that stationary CI engine emissions are adequately addressed through fu el quality regulations and 40 CFR part 63, subpart ZZZZ. It is not clear to EPA what fuel quality regulations the commenter is referring to. No previous federal standards apply to the fuel used in such engines. Subpart ZZZZ does not apply to a ll stationary CI ICE; it only applies to stationary CI ICE greater than 500 hp and located at major sources of hazardous air pollutants (HAP) emissions. Criteria pollutants were not th e focus of subpart ZZZZ, which was a rule developed and designed to reduce HAP emissi ons. This NSPS, on the other hand, must address criteria pollutants. In developing this NSPS, EPA reviewed and considered the requirements of subpart ZZZZ and the emissi ons requirements in this proposal are

157compatible with the emissions requirements of subpart ZZZZ. The control technologies that the two rules rely on are compatible with each other; th e control technologies that are

the basis for the NSPS in some cases can re duce HAP in addition to reducing criteria pollutants. One example is CDPF, which reduces both PM and HAP. Another example

is a NOx adsorber combined with an oxida tion catalyst. EPA has attempted to reduce compliance complexity, particularly for owners and operators, by aligning this regulation with pre-existing regulations for nonroad engi nes and allowing owners and operators to rely on engine manufacturer certificati on to comply with these requirements.

19.0 Costs

19.1 Comment : One commenter (244) believed that new strict emission standards for stationary engines will be met in a cost-effective manner given adequate lead-time. The

commenter cited DPF and DOC control cost s from the California ARB on stationary engines, a CALSTART study on DPF and S CR on passenger ferries, and provided costs for large-scale commercial marine SCR applications in Europe.

Response : No response is needed.

15820.0 Health/Environmental Impacts

20.1 Comment : One commenter (243) made the comment that the proposal fails to mention, but the Agency has acknowledged in othe r settings, that diesel air pollution also poses substantial cancer risk across the country. Several organizations, including EPA, the National Institute for Occupational Safety and Health, the International Agency for Research on Cancer, the World Health Or ganization, California EPA, and the U.S. Department of Health and Human Serv ice’s National Toxicology Program have designated diesel exhaust as a probable or potential human carcinogen. According to the Multiple Air Toxics Exposure Study (MATES -II) conducted for California’s South Coast Air Quality Management Distri ct, about 70 percent of the total inhalation cancer risk from air pollution for the average California resident is due to diesel exhaust.

California’s Office of Environmental Health Hazard Assessment concluded that “longterm exposure to diesel exhaust particles poses the highest cancer ri sk of any toxic air contaminant evaluated...” A separate assessment suggested that the result for the U.S. as a whole is even worse: 80 percent of the to tal cancer risk from hazardous air pollutants

nationwide is estimated to be associated w ith the inhalation of diesel exhaust. The

commenter indicated that it retained Dr. William Nazaroff ( http://www.ce.berkeley.edu/~nazaroff/ ) to conduct a risk assessment of emergency backup generators in several California citie s. Dr. Nazaroff’s analysis found the cancer

risk exceeded one in a million for a re markably expansive zone downwind of an emergency back-up generator. Generators operating infrequently nevertheless had risk zones spanning 10 to 20 average city blocks. In closer proximity to an emergency use

159engine, the estimated cancer risk exceede d ten in a million. Relying on dispersion modeling, risk analysis, state permit data and GI S analysis, the risk assessment found that in four California air quality management di stricts (i.e., South Coast, San Diego, San Joaquin Valley, and Sacramento), some 150,000 children attended schools within the

cancer risk zones of emer gency diesel generators.

Response : EPA acknowledges that there have been links to cancer from diesel exhaust. EPA is finalizing standards of performance for emergency engines that are the most stringent that can justified and the standard s that are being promulgated for stationary emergency CI engines will lead to substant ial reductions in PM emitted even though addon controls will not be required for emergency engines to meet the standards. EPA is also implementing stringent restrictions on the usage of emergency engines for operation during any other circumstances besides fo r emergency purposes, which should reduce this problem. Emergency engines do not operate much; some sources estimate only about 50 hours per year. EPA has noted that there is a very high cost per ton of putting aftertreatment on these engines. We believe that the increas ed upfront costs of engines with aftertreatment are not justified for these engines, which are used so rarely and often in situations where greater and more immediate harm to human hea lth (e.g., fire or flood)

is evident. In addition, EPA does not wish to prevent owners from being able to purchase new emergency engines. Given that emerge ncy engines with aftertreatment will be appreciably more expensive than engines w ithout aftertreatment, EPA believes that substantial increases in cost may dissuade owners and operators from purchasing new emergency engines which, given the importance of these engines, may be

160counterproductive to the goal of better human health and welfare. In particular areas where local regulators are concerned about pr oximity of emergency engines to numerous people, the local regulators can regulate these engines.

21.0 Other

21.1 Public Comment Period Extension

21.1.1 Comment : One commenter (217) said that the 60-day public comment period provides insufficient time to do a thorough analysis and submit comments on the proposed rule. The commenter requested a 30-day extension to the comment period.

Response : EPA denied the commenter’s request for an extension to the public comment period. EPA based its decision on the tight c onsent decree deadline to issue regulations for stationary CI engines and felt that 60 da ys was an adequate public comment period. In addition, EPA pointed out in its denial to extend the pub lic comment period that the proposal was posted on EPA’s website about 1 1⁄2 weeks prior to publication in the Federal Register. Please refer to th e docket for this rulemaking, EPA-HQ-OAR-2005- 0029-0230, for EPA’s official response to the commenter’s request.

21.2 Corrections Needed

16121.2.1 Comment : One commenter (240) stated that there appears to be a typo in §60.4205(a) of the proposed rule. In the second sentence of that prov ision, it appears that the word “non-emergency” should be “emergency.”

Response : There was an inadvertent error in 60.4205(a) of the proposed rule. As the commenter pointed out, in the second se ntence of that provision, the word “nonemergency” should have been “emergency.” Th is has been corrected in the final rule.

21.2.2 Comment : One commenter (235) said that on page 39898 of the proposed rule formulas are given for the conversion from the concentration unit ppm by volume (ppmv) to the mass based unit g/kW-hr. The comment er stated that equation 7 of the proposed rule contains an error. When calculating the mass based unit g/kW-hr, the “actual” ppmv concentration should be used and not the 15 percent O 2 corrected value. The commenter added that the factor of 1.912 for converting ppmv NOx to mg/Nm 3 indicates Nm 3 to be given at 25°C. The commenter said that this needs to be mentioned in the text.

Response : The commenter is correct that th e measured concentration and not the

corrected concentration should be used in equation 7 of the rule. EPA has made this

correction in the final rule. The conversion constant of 1.912 x 10-03 is at EPA-defined standard conditions, which are 20°C (68°F) and 1 atm (14.7 psia ). EPA has clarified this

in the final rule.

21.3 Format of Standards

16221.3.1 Comment : One commenter (259) requested that the emission limits include concentration-based alternatives (e .g., ppmv for gaseous species, mg/m 3 for particulate) or input-based limits (e.g., pounds per gallon of fuel) to the output based limits (e.g., g/hp-hr) so that emissions compliance can be verified for units that cannot readily measure output power. Determination of out put power may not be accessible for all engine sizes and applications. While EP A may consider this a non-issue due to manufacturer certification, there is the poten tial for compliance certification such as testing to be added to NSPS affected units due to concerns about “u seful life.” In this scenario, a concentration-base d alternative to the output-b ased limit would provide the ability to certify compliance based on a stack test, and the comment er recommended that

a concentration-based alternative emissi on limit be included for instances where owner/operator compliance tests are conducted.

Response : Stationary CI engines affected by this NSPS will for the most part be regulated through a certification program and to emission stan dards generally consistent with those that apply to nonr oad diesel engines. Also, manufacturers often produce the same engine for use in nonroad and stationa ry applications. Fo r these reasons, it is important that the emission sta ndards are in consistent units, i.e., g/kW-hr. In addition,

EPA has no emissions data to establish alternative concentration-based emission standards for stationary CI engi nes. EPA believes it is appropriate that the format of the

standards is written in units of g/kW-hr and does not believe it is necessary to include

concentration-based units in the rule. The un its of g/kW-hr will remain in the final rule.

16321.4 Military Training Engines

21.4.1 Comment : One commenter (256) recommended th at the rule exempt engines used in training and testing of m ilitary personnel in the operation, maintenance and repair of engines. These engines may have to be conf igured similarly to engines used by the U.S. or its allies in combat operations, which ma y make it difficult or impossible for them to comply with the NSPS.

Response : EPA agrees that it is appropriate to exempt engines used for military purposes. A national security exemption exis ts already (see, e.g., 40 CFR part 89 subpart J). Engines meeting the conditions specifi ed in 40 CFR 89.908, and the corresponding provisions in parts 94 and 1068, will be considered exempt from the regulations for stationary CI ICE. An engine that recei ves the national secur ity exemption under the non-road engine provisions when purchased wi ll continue to be exempt if used as a stationary ICE, as long as it continues to be used for national security purposes. In addition, for engines that receiv e a national security exempti on will also be exempt from the fuel requirements in section 60.4207 of the final regulations. EPA believes that these provisions address the commenter’s concerns.

21.5 Replacement Engines

16421.5.1 Comment : One commenter (240) stated that a replacement engine exemption from the NSPS requirements (such as is found at 40 CFR §§89.1003 and 1068.240) should be included only for emergency engines.

Another commenter (265) noted that EPA has requested co mment on the appropriateness of including the exemption provisions of 40 CFR 1068.240, which relate to replacement engines. This commenter believed that limited exemption provisions for replacement engines are appropriate. Those exemptions should only be granted for a limited period from the original MY in order to restrict th e perpetual use of higher emitting equipment. For example, New Jersey specifies a 15 year period for turbine overhaul before state of

the art emission limits must be reevalua ted and incorporated as appropriate.

Response : EPA believes it is appropriate to incl ude replacement engine provisions from the nonroad regulations to this rule; however, the provisi on is limited to engines going into equipment that is less than 15 years old. Th is change is reflected in the final rule and EPA has included nonroad sections §§89.1003( b)(7), 94.1103(b)(3) and (4) and 1068.240 in the regulation language for the final rule.

21.6 Temporary Engines

21.6.1 Comment : One commenter (259) expressed that the rule needs to clearly allow for temporary hp replacement using portable engine s to ensure that disruptions and outages during maintenance are minimized and other sh ort term applications are clearly exempt from NSPS requirements. EPA should provi de a clear indicati on that the following

165applications are not considered stationary engines and are exempt from the NSPS for stationary CI engines:

• A unit that temporarily replaces an engine that is undergoing an overhaul, and is

then moved to another location to serve as a temporary replacement for another unit undergoing overhaul;

• An existing spare unit that has been in se rvice prior to the subpart IIII proposal and is used in an engine rotation progra m to replace an engine that is overhauled and moved into the spare engine rotation; and

• A temporary engine that is not the identical make, mode l or hp is acceptable for short-term (not to exceed 90 days) replacement.

Response : EPA agrees that the engines them selves that are used for temporary replacement of stationary engines are nonroa d engines and are not covered by stationary engine regulations, as long they meet the defi nition of nonroad engine and if they are not used beyond the residence limitations in paragr aph 2(iii) of the nonroad engine definition in 40 CFR 1068.30. However, EPA notes that on ce the stationary engine is put back in operation, it is immediately subj ect to all the requirements of this subpart. The residence time period for the installation continues to run while the temporary engine is in operation. Moreover, EPA notes that this subpart, as well as 40 CFR sections 89.1003(a)(5) and 1068.101(b)(3), forbid any atte mpt to circumvent the residence time requirements of the nonroad engine definiti on. Use of a nonroad engine that does not comply with NSPS standards applicable to the engine it replaces can be seen as

166circumvention of the residence time requirement if the engine is used for a period beyond a period that is reasonably necessary for the temporary purpose it is designed to achieve.

21.7 Adjustments

21.7.1 Comment : One commenter (247) was concerne d that Caterpilla r engines with programmable logic controllers (PLC) will be certified using a low emission (low NOx) setting, but could possibly be adjusted in the field to a fuel economy setting (higher NOx). The rising cost of fuel could incr ease the potential for this activity. The commenter suggested that the NSPS require ow ners/operators to k eep a record of all adjustments to the PLC, including the reason for the adjustment and the manufacturer’s certification that the engine operating with the adjusted PLC still meets the emission

standards.

Response : EPA understands the commenter’s concer n that certain stationary CI engines may be adjusted while in service for various reasons including for fuel saving purposes. The commenter’s suggestion is reasonabl e, but EPA believes it would be more appropriate to incorporate provi sions into the rule that limits the owners and operators to changing only those settings that are allo wed by the engine manufacturer. The engine owner or operator must not operate the engi ne outside the manufacturer’s parameters. This provision has been included in the fina l rule and prevents engines from being operated under conditions that would lead to engine out exhaust emissions being out of compliance.

16716821.8 Biodiesel

21.8.1 Comment : One commenter (249) provided b ackground information on biodiesel, commonly made from vegetable oils such as soybean oil, including benefits of using biodiesel fuels in stationary engines. Biodiesel can be used immediately and seamlessly as a clean-burning, no-sulfur alternative fuel or lubricity additive, according to the

commenter. The use of biodiesel contri butes to a longer equipment life, lower maintenance costs and less equipment down time. The commenter proposed that EPA consider offering incentives and an optional te sting program for engine companies to test biodiesel, and proposed the following:

Incentives : Engine companies should receive in centives for conducting biodiesel testing on engines, e.g., they could receive double em issions credits. This would encourage them to conduct this important testing, provi de EPA and other inte rested stakeholders with critical data, and coul d potentially lead to increas ed emissions warranties on

biodiesel.

Testing must not be duplicative : Biodiesel testing should not be duplicative of already required testing on diesel fuel. Rather, the bi odiesel testing could be limited to testing simply on emissions at a certain blended level. The commenter would be very willing to work with EPA to determine which specifi c tests would need to be conducted on

biodiesel to make it bene ficial and acceptable.

169Optional : The testing program must be optional and not mandated.

Response : EPA would like to encourage the use of renewable fuels such as biodiesel in stationary CI engines, but is unable to o ffer incentives and tes ting programs, as the commenter proposed, in the context of this rulemaking.

21.9 Dual-Fuel

21.9.1 Comment : One commenter (261) supported EP A inclusion of liquid pilot units (i.e., dual-fuel units with low le vels of liquid pilot fuel) in the spark ignition (SI) engine equipment category.

Response : No response is needed.

21.9.2 Comment : One commenter (256) said that the rule considers dual-fueled CI engines that use liquid fuel and gaseous fuel at an annual ratio of less than 2 parts diesel fuel per 100 parts total fuel as SI engines, and, therefore, not subj ect to the regulation. The commenter has found that a ratio of 5 part s diesel fuel per 100 pa rts total fuel is a ratio that adequately defines dual-fueled di esel engines using natu ral gas for regulatory purposes. Except as noted below in comme nt 21.9.3, the commenter recommended that dual-fueled engines with a ratio of 5 parts diesel to 100 parts total fuel be considered SI engines.

170Response : Based on information EPA has receiv ed and reviewed, EPA believes that 2 parts diesel fuel to 100 parts of total fuel is an appropriate cutoff fo r the purposes of this regulation. The commenter di d not provide any supporting in formation explaining why it believed a ratio of 5 parts diesel to 100 parts of total fuel should be adopted in the final rule and why these should be considered SI engines. Therefore, the definition of SI engines remains as proposed in the final rule and dual-fuel engines where a liquid fuel is used for CI and gaseous fuel is used as th e primary fuel, with the exception of landfill or digester gas fuels, at an annual average ratio of less than 2 parts diesel fuel to 100 parts total fuel on an energy equiva lent basis are SI engines.

21.9.3 Comment : One commenter (256) said that dua l-fueled engines using diesel fuel and digester or landfill gas may operate at a ratio as high as 30 parts diesel to 100 parts total fuel. These engines may have diffi culty complying with the proposed emission

standards because of the com position of the gaseous fuel, especially if the use of catalyzed emission control equipment is necessa ry. Furthermore, there are environmental benefits to using digester or landfill gas that would otherwise be fl ared, to produce useful power. The commenter recommended that a ll dual-fueled engines using a combination diesel fuel and digester or landfill gas be exempt from the proposed emission standards of this regulation.

One commenter (271) expressed concern regarding engines in landfill gas service. Landfill gas contains siloxanes which will poi son any catalytic device. There is no known reliable technology for removing siloxane s from landfill gas. The NSPS proposes

171the use of NOx absorber technology for NOx control and catalyst technology for PM control. Both of these technologies would be rendered ineffective for engines used to convert the renewable energy from landfill gas methane into useful energy. The problems with siloxanes were noted in 40 CFR part 63, subpart ZZZZ for stationary RICE. The commenter has several landfill-gas- to-energy projects using diesel engines.

The commenter believed that di esel engines provide a very effective technology for using landfill gas. The commenter also recogni zed, through experience, that catalytic

converters will not be effective in this service as a result of landfill gas siloxane content. Diesel engines can be used over a range of landfill gas substitutions for liquid fuel. They also may be used with no landfill gas. In fact, engine startups are done using only liquid fuel. However, once landfill gas is used, the poisoning of the catalyst will quickly reduce, and eventually nullify, the effectiven ess of the technologies suggested in the proposed standard. The commenter’s experi ence has been a 50 percent reduction in catalyst effectiveness in about 200 hours and a greater than 90 pe rcent reduction in less than 300 hours. The commenter requested th at the NSPS exempt CI engines in landfill gas service.

Response : EPA recognizes that ther e may be concerns with a pplying add-on controls to stationary CI engines using landfill or digester gas due to the presence of siloxanes in

these fuels. Siloxanes have been known to poison the catalyst and can reduce the effectiveness of the catalyst within brief periods of time. This was acknowledged in 40 CFR subpart ZZZZ. EPA agrees with the comme nters that it would be inappropriate to require stationary CI engines burning landfill or digester gas to meet emission standards

172that rely on the use of aftertreatment contro ls. EPA, however, does not agree that it is appropriate to exempt stationary CI engines burning landfill or digester gas entirely from the regulation. The problem with using these fuels is, as mentioned, related to the application of aftertreatment controls in co mbination with these fuels. Therefore, any emission standard that does not rely on the use of add-on controls would be suitable. Based on the comments received, the issues related to using landfill and digester gas in stationary CI engines appears to be limited to applying add-on controls. Therefore, EPA believes it is appropriate that stationary CI engines utilizing landfill and digester gas meet the most stringent level of control that does no t require aftertreatment devices, i.e., either Tier 2 or Tier 3, as applicable. The final rule has been written to incorporate this provision. EPA believes this provision resolv es the commenter’s concerns regarding

these fuels.

21.10 SI NSPS

21.10.1 Comment : One commenter (261) stated that the NSPS proposes to regulate NOx, NMHC, PM, and CO. The proposed subpart KKKK for stationary combustion turbines proposed to regulate pollutant s including NOx, CO, PM, HC, and NMHC. The choice of pollutants appears to be based upon the nonroa d and marine standards, and it does not appear that original analysis was conducte d to assess the impacts associated with the array of regulated pollutants for stationary CI engines. The commenter did not offer any specific recommendations regard ing the pollutants included in the proposed standard. However, the commenter recommended that EP A carefully consider the pollutants to be

173regulated when developing the companion SI NSPS, which is scheduled for proposal in 2006. It is important to unders tand that emission profiles differ for liquid-fired CI engines and gas-fired SI engi nes. In addition, utilizati on and operational profiles can affect source category emissions. In fact, due to the utilization profile from stationary CI engines, it is possible that em issions are different than em issions from nonroad sources and regulation of all of the pollutants included in the pr oposed standard may not be

warranted. The commenter offered this comm ent mainly due to concerns regarding the upcoming SI NSPS, and recommended that EPA complete a thoughtful review and analysis of this topic for the SI NSPS proposal to ensure that only pollutants of concern are regulated.

Response : This comment is outside the scope of the NSPS for stationary CI engines. EPA plans to conduct a careful review of which pollutants to be addressed under the upcoming SI NSPS.

21.11 Test Cells

21.11.1 Comment : One commenter (220) expressed s upport of the proposed rule. The commenter manufactures 5 kW fuel cell sy stems that run on pure hydrogen, natural gas or liquefied petroleum gas, and are an off- the-shelf environmental option to traditional diesel back-up generator systems.

Response : No response is needed.

17421.11.2 Comment : One commenter (214) requested that the rule state that diesel engine

test cells/facilities are exempt from the rule.

Response : The final rule states that the rule doe s not apply to stationa ry CI engine test

cells/stands.

175