# 1111 Engine Manufacturers Association® Two North LaSalle Street, Suite 2200, Chicago, IL 60602 Tel: (312) 827-8700 I Fax: (312) 827-8737 I www,enginemanufacturers.org**······}}·imimikh~hl~~]~iii!!ltt_IIII11LIIIIIIIII** • July 29,2009

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Dr. Robert 1. Wayland Leader, Energy Strategies Group U.S. Environmental ProtectionAgency Office ofAirQualityPlanning and Standards 109 T.W. AlexanderDrive (D243-01) Research Triangle Park, NC 27709

Re: Supplementto EMA's Comments Regarding the ProposedNESHAP For StationaryRICE

DearBob:

This letteris afollow-up to ourmeeting onJune 22, 2009, during whichwe discussedthe significant concerns that the Engine Manufacturers Association ("EMA") has with respectto the national emissions standards for hazardous air pollutants ("NESHAP") that U.S. EPA has proposedfor stationaryreciprocating internal combustion engines ("RICE"). (SeeNPRM, 74 FR 9698, March 5, 2009.) Inparticular, this letterwill reiterate the specific points that we discussed regarding the Agency's authority under the Clean Air Act to adopt work/management practices
or operating requirements in lieu ofspecific HAP emission standards for: (i) stationary RICE during periods ofstart-up and malfunction; (ii) emergency stationary RICE; and (iii) stationary RICE less than 100hp. As you know, these issues, which are discussed in further detail below,
are likely to create fundamental and inherently unacceptable problems for the engine manufacturing industry ifEMA's recommendations are not incorporated into the final NESHAP rule forthe stationaryRICE in question. StationaryRICE Start-Up Operations andMalfunctions During periods ofRICE start-up, engine loads and exhaust temperatures are not high enough to allow for the effective operation of catalyst-based exhaust treatment systems or devices, and also are not representative of the engine loads, exhaust flows and temperature profiles that RICE experience during their normal and intended operating conditions. Thus, while theAgency is correctin its conclusion that emission standards based onthe use ofcatalystbased emission reduction systems cannotbe applied to periods ofengine start-up, the Agency is incorrect in its assumption that the emissions performance of an engine during start-up operations can be made equivalent to the best-performing RICE, not equipped with catalystbased emission controls, but operating under stabilized steady-state conditions. Stabilized, fully warmed-up, steady-state operating conditions yield engine loads, exhaust temperatures and volumetric flows that are inherently different from start-up operations, and, more importantly,

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EMA European Office, Hasenacker Strasse 32, 71397 Leutenbach, Germany I Telephone/Facsimile: +49 7195 957126 EMA is a Non Governmental Organization in Special Consultative Status with the Economic and Social Council ofthe United NationsJuly 29, 2009 Dr. RobertJ. Wayland Page 2

that are inherently better suited to achieving lower emission levels than during transient, lowload, low-temperature, start-up operations. Thus, the two disparate types ofoperating conditions (start-up v. stabilized operations) cannotbe assumed to be capable ofyielding the same type of optimized emission levels. To the contrary, any such assumption would be unreasonable and invalidas abasis forregulatory action.

This necessary conclusion is further supported by the fact that there are no specific, verified and repeatable test procedures for measuring and quantifying HAP emissions during periods ofRICE start-up operations. There is no start-up test cycle, no definedprotocol for what constitutes start-up, and no uniform and repeatable methodology for capturing and recording start-up emission levels in-use in a manner that could be objectively assessed against a benchmark standard for start-up emissions. Consequently, specific HAP standards for start-up emissions are infeasible andunreasonable onthesebases as well.

In light ofthe infeasibility ofestablishing HAP emission standards for engine start-up periods that are equivalentto the standards applicable to warmed-up, normal steady-state engine operations, the provisions of CAA section 112(h) clearly apply. Under section 112(h)(l), 42 U.S.C. §7412(h)(l), if it is not feasible to prescribe or enforce a HAP standard for certain stationary sources, a work practice or operational standard may be established. Infeasibility for suchpurposes specifically includes a situationwhere, as in the case ofengine start-up operations, "the application of [emission] measurement methodology

... is not practicable." 42 U.S.C. §7412(h)(2)(B). Significantly, the courtin the SierraClub case (No. 02-1135) specifically noted the availability ofsection 112(h) as ameans for dealing with start-up emissions.
Thus, in lieu of any specific HAP standard applicable to stationary RICE emissions during start-up operations, EPA should adoptaworkpractice similarto the following:

RICE start-up operations, which constitute the time period from engine ignition to the time when the catalyst temperature is sufficient to enable effective catalyst operation, shall be minimized. Start-up times shall not exceed 30 minutes or the manufacturer's start-up recommendations, unless the Administrator approves a longer time for certain engine classes or approves a longer start-up time to address special conditions andrequirements**(~,** cold weather installations) in response to a petition from the owner/operator. During initial commissioning, or after modification (see 40 CFR §60.14) or reconstruction (see 40 CFR §60.15) ofthe engine/equipment installation, additional time may be required for the set-up procedures before normal catalyst operation can be expected. Malfunctioning RICE shall be shut down and repaired as soon as practicable based on the engine's application anduse.July 29,2009 Dr. RobertJ. Wayland Page 3

Withrespectto the operation ofRICE during amalfunction, itmakes no sense

-- andthus is inherently unreasonable

-- to assume that amalfunctioning engine can and shouldperformin a manner equivalent to the best performing RICE not equipped with catalyst-based emission controls. The very essence ofa malfunctioning engine isjustthat

-- it is malfunctioning and so not performing in an optimized manner for emissions purposes, or any other purpose for that matter. Accordingly, itis quite simply irrationalto require such amalfunctioning engine to meet any sort ofMACT-based standard. In that regard, andjust as in the case ofstart-up operations, there are no established and repeatable test cycles or procedures for measuring HAP emissions from stationary RICE during periods ofmalfunctions. As a consequence, and again pursuantto the flexibility provisions ofCAA section 112(h), EPA shouldadopt a "workpractice" to limitthe emissions ofHAP during any period ofRICE malfunction. In particular, and as noted above, that work practice should require that any malfunctioning RICE be shut down and repaired as quickly as possiblewithdueregard fortheuse and application ofthe stationaryRICE atissue. Emergency CIEngines Emergency stationary RICE generally operate less than 50 hours per year, and so have "minimal" ifany impact on ambient air quality. (See 74 FR at 9706.) Nonetheless, EPA is proposing to apply a "MACT floor" HAP emission standard (of40 ppmvd CO) to emergency compression-ignition ("CI") engines rated from 50hp to 500hp and located at major sources, as well as to emergency engines rated above 500 hp and located at area sources. The net effect of such a MACT floor standard could lead to the forced replacement ofup to 88% ofthe covered emergency CI engines, since the standard is premised on the emissions levels achieved by the best-performing 12% of the covered engines. Given the fact that there are approximately 700,000 emergency stationary RICE in the greater than 300hp category alone, that is a thoroughlyunreasonableresult.

The minimal emissions impact of emergency RICE do not warrant costly emISSiOn reduction requirements. It was for thatveryreason thatEPArejected apotentialrequirement for add-on emission controls for emergency stationary engines. (See 74 FR at 9706.) Yet, in the
same breath, EPA is proposing standards that couldnecessitate the outrightreplacement ofup to 88% ofexisting emergency RICE with new engines, the costs ofwhich are far in excess ofthe costs for add-on controls. Again, such a proposal is inherently unreasonable and costprohibitive.

Alternatives to specific MACT floor HAP standards are available for emergency stationary RICE under the relevant provisions ofthe CAA. First, with respect to emergency RICE located at area sources, section 112(d)(5) ofthe CAA, 42 U.S.c. § 7412(d)(5), specifically authorizes EPA to promulgate management practices in lieu ofspecific HAP standards. Given the wholly unacceptable cost ramifications of EPA's pending proposal, EPA should eschew imposing a specific HAP standard on emergency engines, and instead should adopt a management practice (just as was done in the NSPS rulemaking for emergency stationary CIJuly 29, 2009 Dr. RobertJ. Wayland Page 4

RICE) generallylimitingthe non-emergency operation ofstationaryemergencyRICEto no more than 100 hours per year. Such a management practice will ensure that the emissions impacts from such engines remain minimal, while at the same time avoiding the enormous and unreasonable costburdens ofEPA's currentproposal.
Second, with respect to emergency RICE located at major sources, EPA should invoke the flexibility provision ofCAA section 112(h). As noted, that provision allows the Agency to promulgate an operational standard, such as an annual hours ofuse limit, when it is not feasible to prescribe or enforce a specific HAP emission standard. For stationary emergency CI engines, advanced emission control systems are not feasible because, unless there is an actual and sustainedemergency (when far more than short-term airquality is at stake), those engines do not operate long enough during theirperiodic maintenance and service testing (the only othertimes such engines operate) to reach sufficiently high and stabilized temperature and load points to optimize the performance capabilities ofemission control systems (including, but not limitedto, add-on controls). As aresult, it is not feasible to utilize "a conveyance designed andconstructed to capture such [HAP] pollutants" in an effective mannerfor emergency CI engines. Pursuantto CAA section 112(h)(2)(A), such circumstances can constitute the type ofpractical "infeasibility" sufficient to warrant the promulgation of an operational standard (i.e., limiting the nonemergency operation of emergency RICE to 100 hours per year) in lieu of a specific HAP standard. Accordingly, in light ofthe foregoing, EPA should adopt an operational standard in lieu of any specific MACT floor standard for stationary emergency CI RICE. As in the NSPS rulemaking, that operational standard generally should limit the non-emergency operation of suchengines to no more than 100hoursperyear. Non-Emergency RICE 

### Less Than lOOhp

The same rationale that applies to emergency CI RICE also applies to non-emergency stationary CI RICE less than 100 hp. Those engines likewise contribute minimal quantities of HAP emissions and it is not cost-effective to require any type ofadd-on controls for such small engines. Accordingly, with respect to engines less than 100 hp located at area sources, EPA should adopt management practices under CAA section 112(d)(5) to control the emissions from such very small stationary RICE. Those management practices could include requirements to follow the engine manufacturers' maintenance instructions andto use ultra-low sulfurdiesel fuel. With respect to engines under 100hp located at major sources, CAA section 112(h) similarly provides the Agency with sufficientdiscretionto adoptworkpractices in lieu ofspecific MACTbasedstandards.

EMA appreciates the opportunity to submit these follow-up comments regarding certain ofthe concerns expressed during our most recent meeting with Agency, and we thank you inJuly 29,2009 Dr. RobertJ. Wayland Page 5

advance for your careful consideration ofthese very important matters. In the event that you have any questions regarding EMA's concerns, please do nothesitate to contactme.

TAF:kj

cc: PennyLassiter (lassiter.penny@epa.gov) Melanie King (king.melanie@epa.gov) Michael Horowitz (horowitz.michae1@epa.gov) EMA StationaryEngine Committee

EMADOCS: 35949.1