2008-02-06 Supplemental Screening Health Risk Assessment TN-45277

7/29/2019 2008-02-06 Supplemental Screening Health Risk Assessment TN-45277

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Ms. Angela Hockaday ICalifornia Energy Comm issionDocket Unit, MS-415 16 Ninth StreetSacramento, CA 95814-55 12

DOCKET06-AFC-7,L

0-6 2008DATE -FEB 0 6 noca:RECD. - I

Plaza Towers55 5 Capitol Avenue Suite 6 0 0Sacrarr~entoCA 958 14Tel* 916.441.6575Fax* 91 6 .441.6553

February 6, 2008

Re: HUMBOLDT BAY REPOWERING PROJECTPACIFIC GAS & ELECTRIC COMPANY'SSUPPLEIVIENTAL SCREENING HEALTH RISK ASSESSMENTDOCKET NO. (06-AFC-7)

Dear Ms. Rod riguez:Enclosed for filing with the California Energy Commission are one original and 12(Twelve) copies of the PACIFIC GAS & ELECTRIC CONLPANY'SSUPPLEMENTAL SCREENING HEALTH RISK ASSESSMENT, for the HumboldtBay Repowering Project (06-AFC-7).

Sincerely, A,!,L2.3bd &,,&M rite Cosens

Southern Ca lifornia Office 10 0 No rth Brand Boulevard Suite 6 18 Glenda le CA 9 1203LLr.


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February 5,2008 sierraresearchJohn Kessler

Project ManagerCalifornia Energy Commission15169th Street, MS-15Sacramento, CA 958 14

1801 J StreetSacramento, CA 958Tel: (916) 444-6666F a : (916) 444-8373Ann Arbor, MITel: (734) 761 6666F a : (734) 761 6755

Re: Humboldt Bay Repowering Project06-AFC-7Dear Mr. Kessler:As requested by the staff, the applicant has prepared a supplemental screening health riskassessment and a proposed condition of certification for public health that would linnit theoperation of the Humboldt Bay Repowering Project (HBRP)WW i l l dual fuel en a e s n DieselMode on a five-year average basis. The proposed condition of certification is supported by ananalysis of curtailment operation by the existing Humboldt Bay Power Plant to demonstrate thatthe proposed five-year averagingperid is both necessary and sufficient to allow PG&E to meetits obligation to serve the Humboldt area during natural gas curtailments, as well as formaintenance and operational testing and required emissions testing. As requested b:y the CECstaff, this analysis uses the CTSCREEN version of the complex tarain model, rather than theCTDMPLUS version of the model, to address the staffs concern regarding the meteorologicaldata we were required to use by the North Coast UnifiedAir QualityManagement District. Thisanalysis also includesan assessment of acute and chronic non-cancer risks.We hope that this supplemental analysis and proposed condition will resolve the rmtainingpublic health issues related to the proposed HBRP. If you or your staff has any questionsregardingthis submittal, please do not hesitate to call.Sincerely,ymC,&hary RubensSeniorpartnekattachmentcc: Rick Martin, NCUAQMDGreg Lamberg, Radback EnergyScott Galati, Galati and BlekSusan Strachan, Strachan Consulting

\, Doug Davy, CH2M HillKen Horn


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Supplemental Analysis forHealth Risk from th e HBRPThe applicant has prepared a supplem ental screening health risk assessment to addressthe CE C s ta ff s concern regarding potential public health impacts from the proposedHBR P. We believe that the supplemental risk assessment, combined with the applicant'sproposed additional restrictions on Diesel mod e operation in the new reciprocatingengines, should address the st a ff s concerns regarding the public health impacts. Thesupplemental health risk assessment evalu ates cancer, chronic non-cancer and acute risksfrom the project based o n an assum ed 5-year average o f 5 10 plant-wide e ngine hours peryear of liquid fuel operations by the W artsila engines. The applican t's proposedcondition of certification for public health is attached.The suppleme ntal analy sis addresses the following issues raised by staff during theDecem ber 14 ,2007 , and January 1 6,20 08, PSA workshops:

1. Mo deling methodology: The supplemental analys is of health risk uses th.eCTD MPL US model in screening mode, which is also referred to as CTS(2REEN.The ana lysis also demonstrates that the conversion factor used by C TS C IE EN toscale modeled one-hour average impacts to annual avera ges is conservatively highfor this particular site, based on an ana lysis of site-specific me teorology.2. Cancer risk: The supplemental analys is results in a cancer risk of 9.8 in onemillion, below the threshold of significance of 10 in one million. Acu te andchronic health hazard indices (H HIs) are also shown to be well below thesignificance threshold of 1. The supplemental analys is accou nts for the expectedoperation of the HBRP engines in Diesel mode without abatement devices duringthe commissioning period.3. Alternatives: The supplemental analysis takes into acco unt the expectedreduction in Diesel particulate matter em issions from the stacks that will beequipp ed with oxidation catalyst post-combustion c ontrols.4. Mu ltiyear average for Diesel mode opera tion limit: The supplemental analysisdemonstrates that a 5 year averaging pe riod will be adequa te to allow operation inDiesel mo de during anticipated testing and maintenance, em issions testing andreasonably foreseeable curtailment periods.

The se issues are discussed in more de tail below.Modeling MethodologyThe CTD MPL US model is shown in Table 4.2 of the OEH HA HR A guidance manual' a sthe recom men ded air dispersion mo del for refined analyses in complex terrain, for bothshort-term and long-term averaging periods. The screening HRA s submitted by theapp lican t in sep tem ber2 and ~ o v e m b e r ~007 were prepared using the CTDM PLlUSmodel. The CE C staff has expressed conc erns regarding the preparation of the'OEHHA,"The A ir Toxics Hot Spots Program Guidance Manual for Preparation of Health RiskAssessments," August 2003.Sierra Research, "Revised Air Quality Impact Analysis for PG &E 7sHumboldt Bay Repow ering Project,"transmitted to the N CUAQMD on September 11 , 2 0 0 7 .Sierra Research, "Supplemental Screening Health Risk Assessment for PG& E9 sHumboldt BayRepowering Project," transmitted to the NCU AQ MD on Novem ber 9 , 2 0 0 7 .


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meteorological data set used in the CTDM PLUS m odeling analysis that was pal? o f theseHRA s. Therefore, the supplemental health risk assessment was based on the version ofCTD MP LUS that does not require meteorological data, CTSCRE EN. CTSCW ,EN isshown as a recommended air dispersion model for screening analyses in complex terrain,but it appe ars only in the list of recomm ended m ode ls for "short-term" averaging periods(1- to 24-hour averages) in that table. N o other discussion of CTSCR EEN is provided inthe O EHHA guidance document.The 2003 OEH HA document com bines information from four technical supportdocum ents onto a guidance manual for the preparation of health risk assessment^.^CTSCREEN is discussed in detail in Part IV , finalized in September 2000:

The CTSC REE N model (Perry et al., 1990) is the screening mode of the C omplexTerrain Dispersion Model (CTDMPLUS). CTSCREEN ca n be used to modelsingle point so urces only. It may be used in a screening mode for multiplesources on a case by case basis in consultation with the District. CTSCREEN isdesigned to provide conservative, yet theoretically more sound, worst-case 1 hourconcentration estimates or receptors located on terrain above stack height ...CTSCRE ENproduces identical results as CTD MPLUS if the same meteorology isused in both models.'CTSC REEN is shown in Table 4.2 as a recommended screening model for short-termaveraging periods, but h as been om itted from the table under long-term averagingperiods. We believe that this is an oversight, because the 2000 g uidance documt:nt a lsosays,

Internally-coded time-scaling actors are applied to obtain other averages (seeTable 2.8). These actors were developed by comparing the results of simulationsbetween CTSCREE N and CTDMP LUS or a variety of scenarios and provideconservative estimates (Perry et al., 1 9 9 0 ). ~

Tab le 2-8 ("Time-scaling factors internally coded in CTSC REEN ") explicitly includesscaling factors for the annual averaging period, indicating that CTSC REEN can be usedto obtain annual averages.The CEC staff has also expressed co ncern that the annual "time-scaling" (persistence)factor used in C TSCR EEN to con vert the model-generated one-hour averages to annualavera ges may not be sufficiently conservative for the terrain in the vicinity of the project.To address this concern, we reviewed the CTSC REEN guidance document to determine

OEHH A developed fou r Technical S upport Docum ents (TSDs) in response to statutory requirements,which provided th e scientific basis for values used in assessing risk from ex posure to facility emissions.The four TSDs describe acute Reference Exposure Levels (RELs), chronic RELs, cancer potency factors,point estimates and distributions for exposure parameters, and the general exposure a ssessmentmethodology. See h t tp : / /www . o ehha . c a . g o v / a i r / ho t ~ s po t s /HR l .OEHHA, "Air Toxics "Hot Spots" Program Risk Assessment Guidelines Part IV Exposure Assessmentand Stochastic Analysis, Technical Support Document," September 2000, p. 2-29. Note that the statement,"CTSC REEN can be used to model single point sources only," is incorrect--CTDM PLUS is a multiplesource model even when used in screening mode.Ibid. -2 -


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how the internally-coded persistence factors were developed. The CTSCREEN guidancedocument says,A number of options or converting 1-h[our] estimates to 3-h and 24-h HSH andannual estimates were considered by the Technology-Transfer Workgroup, and itwas decided that the only workable approach would be to use simple scalingfactors. The workgroup used the results of a comparison study betweenCTSCREEN and CTDMPLUS to select appropriate actors for conversion ...@om1 h to annual estimates of worst-case impacts. The st u 4 included a wide varietyof source and terrain types and sourceherrain configurations7...

To evaluate the conservatism of the internally-coded 1-hour average to annual averagepersistence factor for this particular sourcelterrain configuration, we compared t:hehighest one-hour average concentration modeled on Hill 1 (Humboldt Hill, where thehighest modeled complex terrain impacts from the project are located) for the ca.ncer riskassessment using CTSCREEN with the highest annual average concentration modeled forthe same inputs using CTDMPLUS. Because we have five years of meteorological data,five annual averages were generated from CTDMPLUS. The ratios are summarized inthe following table.CTDMPLUS Annual CTSCREEN I- hr Site-SpecificMet Data Year Average Conc, pglm3 Average Conc, pglm3

2001 7.13 326.04

This analysis suggests that the persistence factor for converting CTSCREEN-modeledone-hour average concentrations to annual averages for this sourcelterrain configurationshould be 0.022, well below the internally-coded factor of 0.03 in the CTSCREElNmodel. Thus, the use of the default CTSCREEN persistence factor is health-conservativefor this site.

Maximum

Cancer RiskThe supplemental assessment of cancer risk from the project produced the result:; shownin the following table. This table has been formatted to make it directly comparable toPublic Health Table 7 in the PSA.The supplemental cancer risk assessment was based on the assumptions outlined below.

0.0i!2 1.13

During the commissioning period, the engines are expected to operate as follows:

326.04

- - - -'USEP A, "User's Guide to CTDMPLU S: Volume 2: The Screening Mode (CTSCREEN )," EP,4/600/8-901087, October 1990 . -3-


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o 20 hours per engine without abatement devices installed, for a total of 200engine-hourso 45 hours per engine with abatement devices installed and operating, for atotal of engine-450 hours

DPM emissions during the commissioning period are expected to be(20 hrslengine * 10 engines * 5.56 l b h ) + (45 hrslengine * 10 engines * 3.89 lbhr)

= 2,862.5 lb DPMExcluding the commissioning period, average annual Diesel mode operatinghours are assumed to be 5 10 plant-wide engine hours per year, reflecting; heassumed level of operations associated with maintenance, testing (includingagency-mandated air emissions testing), and operation during natural gascurtailments (excluding curtailments attributable to acts of God). Thiscorresponds to an annual average DPM limit each year of 1,983.9 lblyr.

A 70-year average DPM emission rate was calculated for the HRA as follows:Average DPM emission rate= [(DPM during commissioning)+ (70 * annual average DPM emission rate)] /70 years= [2,862.5 lb + (70 * 1,983.9 lb)]/70= 2,024.8 lb DPM per yearThis is modeled as the equivalent of 520.5 hours per year of Diesel mode:loperation at a DPM emission rate of 3.89 lbhr. This calculation accounts for theuncontrolled operation of the engines in Diesel Mode during the commis:sioningperiod, as well as up to an average of 5 10 hours per year of operation formaintenance and testing, emissions testing and curtailment operations each yearfor 70 years.Risk-weighted emission rates of each TAC from each source were modeled usingCTSCREEN in complex terrain8

The modeling analysis for the previous HRAs (subm itted in September and November 2007) showed thatthe maximum health risks were found in complex terrain, and there are no changes to stack parameters inthis revised HRA that would affect the locations of the maximum risks.-4-


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1 Formaldehyde I 1.08 I 0.74 1Risk per Million

1 Benzene 1 0.29 I 0.20 1Derived (OEHHA)Method

1 Acetaldehyde 1 0.069 I 0.048 I

Average PointEstimate

- - - - - - -due to Naturalfrom Wartsila Enaines 4.4 - I

1 NaphthalenePAHs (Note 1)1,3-Butadiene

( Total Risk (all sources) I 9.78 1 6.73 1

0.0390.0242.9

Risk due to DieselParticulate Matter fromWartsila EnginesRisk due to DieselParticulate Matter fromEmergency GeneratorRisk due to DieselParticulate Matter from Fire

I Pump

Additional d etails regarding the emission rates used in the sup plemental cancer riskassessm ent are provided in Attachment A.

0.0270.0048

2.0

Health Hazard Indices

5.4

0.02

0.03

The acute and chronic health hazard indices (HHIs) were also reevaluated usingAERMOD and CTSCREEN. Acute HH Is were evaluated for both natural gas mode andDiesel mode operations. The chronic HHI was evaluated for annual operation, consistentwith the assumptions outlined above for the supplemental cancer risk assessment. Thesupplemental assessm ent of HH Is from the project produced the results shown in thefollowing table. This table has been formatted to make it directly comparable to PublicHealth Table 3 in the PSA.

3.7

0'01 I0.02

1 T v ~ ef HazardlRisk I Hazard IndexlRisk I Sianificance Level 1 Sianificant? 1I Acute Noncancer,1 natural gas mode 0.57 1 OAcute Noncancer, Diesel1 modeChronic NoncancerIndividual Cancer

0.099.78

1 O10 in one million No


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AlternativesOne o f the options suggested by the CE C staff at the w orksho p to reduce the risk to thepublic was reducing DPM emissions from the stacks with post-combustion controls. A swe have discussed previously, the applican t's proposed daily and annual limits for totalPM loPM2.5 impacts from the project were based on an expected 30 % reduction inem issions from the oxidation catalysts.9 In preparing previous ca ncer risk assessments,however, the applicant had not accounted for the expected control of DP M from theoxidation catalysts. Additional research indicates that the oxidation catalysts areexpected to be very effective in reducing both the mass of DP M and the organiccompounds-specifically the PAHs-that contribute to the mutagenicity of DP M. Wehave accounted only for the expected control of the mass of D PM in this supplennentalcancer risk analysis, using the same 3 0% efficiency that is expected to be achieved fortotal Diesel particulate. Supporting information is provided in Attachment B.

Multiyear Average for Diesel Mode Operation LimitA part of the supplemental HRA,we updated and refined the evaluation of reasonablyforeseeable liquid fuel operating hours that was originally provided to the CEC sraff aspart of the response to Workshop Query 4 on February 14 ,20 07 . In addition to a.dding2007 HB PP opera ting history to the analysis, we had further discussions with PG& Eoperations staff and determined tha t the peaking turbines (mobile electric power plants,or ME PPs) generally op erate during curtailment only when thermal units are curtailed--other ME PP operation is related to voltage support or because o ne of the thermal units isnot available. How ever, as a conservative worst-case assumption for this revisedanalysis, M EPP operations during the c oldest months (Novem ber, Decem ber, Jan.ua1-yand February) w ere assumed to be curtailment-related even in years when operationalhistory show ed that the boilers were not c urtailed (1 997 through 1999 and 2002 tllrough2007).The a nalysis also includes an evaluation of various averaging periods to determ ine, basedon the MM Btu of fuel used and M Whrs generated at HBP P during curtailments, howmany M W hrs of liquid fuel operation would be required of the new W artsila engines.The highest one-year period over the past 14 years was 2007-based on the conservativeassumptions regarding curtailment operations outlined above, in 2007 the HBRP engineswould have been required to operate on liquid fuel for approximately 754 full-loald hours.The highest 3-year average over the past 14 years is approximately 490 hours per year;the highest 5-year average over the sam e period is approximately 350 full-load hours.As before, these calculations are assumed to reflect only curtailment hours. Emissionstesting on liquid fuel is expected to require a total of up to 60 hou rs per year, and othertesting and maintenance activities must also be provided for. Overall, we believe that theproposed 5 10 hour per ye ar limit can be com plied with on a 5-year average ba sis.Bec ause curtailment-related hou rs alone on a 3-year avera ge basis are expected to be at

Sierra Research letter to Rick Martin, APCO, NCUA QM D, "PM Control Efficiency o f Diesel OxidationCatalysts," August 30, 2007. -6-


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nearly 500 hours per year, PG& E does not believe that a 3-year averaging period wouldprovide an ade quate margin for required maintenance and testing (includ ing emissionstesting) or in the event of several consec utive unusually co ld years.Th e proposed condition of certification includes one proposed limit for DPM emittedduring from the W artsila engines the first year of operation, which includes thecomm issioning period as well as potential curtailment, maintenance and operationaltesting operations, and a second limit expressed as a 5-year rolling average. Theseproposed limits were calculated a s follows:First year:

2862.5 lb DPM for comm issioning operations plus 1,983.9 Ib DPM for otherrequired liquid fuel operations= 4,846.4 Ib DPM /yr

Subsequent years:1,983.9 lb DPM/yr a veraged ov er 5 years= 9,919.5 lb DPM cum ulatively over any consecutive 5-year period


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AttachmentAProposed Condition of Certification for Public Health


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PH-SCx: The project owner shall limit the DPM emissions from com binedoperations of the ten Wartsila reciprocating engines in Diesel Mod e as follows:a. not more than 4,846.4 pounds during the first twe lve mo nths afl:er initial

operation of the first u nit; andb. not more than 9,919.5 po unds during any subsequen t 5 calendar yearperiod, not including emergen cy operations when natural gas is n otavailable to the p ower plant as a resu lt of an Act o f God.Verification: The project owner shall include in the quarterly operation report(AQ-SC9) a sum mary of all DPM em issions during Diesel Mode operationsubject to this co ndition during the reporting quarter and cumulatively for the 5calendar year p eriod. Except as provided below, DPM emissions during DieselMode o peration shall be calculated using valid fuel use records, source testresults, and APC O approved emission factors and me thodology. DPM elmissionsduring D iesel Mode operation without abatem ent of emissions by the oxidationcatalyst shall be calculated using an emission rate of 5.56 pounds p er enginehour.


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Projected Dlesel Mode Operation at HBRP During Natural Gas Curtailments: Actua l Histori cal011Use Basis

HBRPProposedLimit (4)20072006200520042003200220012000199919981997199619951994Average1. Oil bums during 2000 and 2001 were economic oil bums. HBRP will be prohibited from burning iquid fuel for this reason, so

economic oil bums are not included in this analysis. In 1994, 1995 and 1996, residual oil was burned in the boiler toreduce inventory. This will not occur at HBRP, so boiler oil use in these years was also eliminated from the analysis.2. Per PGBE operations staff, MEPPs generally operate during curtailment only when thermal units are curtailed- other MEPP operation is related to voltage supportor because one of the thermal units is not available. However, to be conservative, all MEPPs operation n months of Nov, Dec, Jan and Feb assumed to berelated o curtailments.3. For 1998 and2003, assume that MEPPs curtailment operations are 40% of total annual operations (based on average of 1999 and2002 data).4. Based on 510 hrslyr.5. Hours shown reflect only operations during natural gas curtailments and do not include required operations for operational testing and maintenanceand emissions testing purposes.

Liquid Fuel Consumption at HBPP(MMBtulyear) (1)

Boilers MEPPs (2) Total

75,93999.591 79,829 179,42117,431 66,294 83,725

0 58,364 58,3640 13,570 13,570

5,496 49,089 54,5854,475 38,580 43,055nla nla nlanla nla nla

0 48,478 48,4788,297 29,392 37,689

0 0 0nla 53,665 53,665nla 27,944 27,944nla 24,978 24,978

HBRP Liquid Fuel Heat Rate:

Total OilGenerationBoiler 011 MEPPs at HBPPMWhrs MWhrs (3) (MWhrslyr)

7,181 5,360 12,5413,937 4,147 8,084

0 3,754 3,7540 855 855

41 0 3,334 3,744350 2,607 2,957nla nla nlanla nla nla0 3,329 3.329

583 1,979 2,5620 0 0nla 3,006 3,006nla 1,657 1,657nla 1,603 1.603

8949 BtulkwhHeat Input EquivalentRequired by HBRP LiquidHBRP to Percentage FuelGenerate Equlv. of Proposed OperatlngMWhrs HBRP Oil Hours Per(MMBtulyr) Use Year

147.79% 753.712.22872,344 95.27% 485.933,595 44.24% 225.67,651 10.08% 51.433,507 44.12% 225.026,461 34.85% 177.7nla nla nlanla nla nla29,791 39.23% 200.122.926 30.19% 154.0

0 0.00% 0.026,901 35.42% 180.714,828 19.53% 99.614,345 18.89% 96.3

220.814-yr average

Average HBRP Liqu id Fuel Operating HoursPer Year, Curtailment Only (5)HlghestSlngle Max 3-yr Max Cyr Max 10-yrYear average average average

488.4 348.3 284.2254.3 233.1 190.0167.3 169.9 151.8151.4 151.4 136.1201.4 200.9 141.7177.7 177.3200.1 118.0177.0 133.7118.0 126.9111.5 106.193.4125.5

753.7 488.4 348.3 284.2Max year 3-yr avg 5-yr avg 10-yr avg


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Attachment BCalculation of M odel Input V alues for Supplemental Cancer Risk Assessm~ent


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Table 8.1A-8HBRPAnnual and Maximum Hourly Non-Criteria Pollutant Emissions for Wartsila Reciprocating EnginesRev 2/08

PollutantAmmoniaPropyleneAcetaldehydeAcroleinBenzene1,3-ButadieneDiesel PM (8)EthylbenzeneFormaldehydeHexaneNaphthalenePAHs (as B(a)P) (9)TolueneXyleneTotal HAPS (excluding Diesel

Maximum Hourly Emissionsper Engine, lblh r (5)

Nat Gas Diesel FiringFiring (5) (6)

1.93 2.1 10.46 0.250.04 2.26E-03

4.99E-03 6.98E-040.02 6.59E-020.03 --- 3.890.01 -0.33 1.44E-020.10 -

2.22E-03 1.06E-021.81E-06 4.05E-052.04E-02 2.44E-025.48E-02 1.75E-02

ICE TotalAnnual

Emissions (7)t PY

62.8414.661.440.160.591OO1.010.1910.693.090.07

4.68E-050.651.7619.65

Natural GasEmissionFactor (1)IblMMscf

(4)5.38E+005.29E-015.90E-022.18E-013.67E-01-7.1 1E-02

2.361.13E+002.51 E-021.71E-052.39E-016.46E-01

PM)=

ControlledNatural Gas

Em Factor (2)l lMMscf

nla3.23E+00

DieselEmissionFactor (3)IblMgal

(4)3.85E-01

ControlledDiesel EmFactor (2)IblMgal

nla2.31 E-012.08E-036.42E-046.06E-02---

inc-9.78E-033.73E-052.24E-021.61 E-02

Hazardous Air Pollutants3.17E-013.54E-021.31E-012.20E-014.27E-02

inc6.80E-011.51E-021.03E-051.43E-013.88E-01

3.47E-031.07E-031 O1 E-01------1.32E-02--1.63E-026.21 E-053.74E-022.68E-02


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Notes:(1) All factors except hexane and formaldehyde are CATEF mean values for natural gas-fired IC engines.Hexane is from AP42 Table 3.2-2; formaldehyde is based on vendor data.(2) 40% control efficiency for oxidation catalyst applied for all TACs except formaldehyde. Source: BAAQMD PDOCfor Eastshore Energy Center, April 30, 2007. Formaldehyde emission factor provided by vendor reflects ox cat control.(3) All factors are CATEF mean values for large Diesel engines (SCC 20200102).(4) Based on 10 ppm ammonia slip from SCR system.(5) Based on maximum ICE firing rate of 143.9 MMBtuIhr and fuel HHV of 1,021.I tulscf of natural gasand 0.79 MMBtuIhr and fuel HHV of 136,903 Btulgal or pilot Diesel fuel0.14088 MMscfIhr natural gas0.01 Mgallhr Diesel fuel(6) Based on maximum ICE firing rate of 148.9 MMBtulhr and fuel HHV of 136,903 Btulgal or Diesel fuel1.09 Mgallhr Diesel fuel(7) Based on maximum ICE firing rate (from (3)) for 6447 hrslyr on natural gas and pilot Diesel fuel.908.0 MMscfIyr of natural gas0.3 Mgallyr Diesel fuel(8) Based on annual average total of 515 hrs of backup Diesel fuel operation; Front half only, per ATCM. 30% control efficiency for oxidationcatalyst applied for Diesel PM. Source: Sierra Research etter to Rick Martin, APCO, NCUAQMD, "PM Control Efficiencyof Diesel Oxidation Catalysts," August 30, 2007.(9) Emission factors for individual PAHs weighted by cancer risk relative to B(a)P and summed to obtain overall B(a)Pequivalent emission rate for HRA.

Mean EFNat Gas Diesel PEF Equiv. PEF-Weighted EFNat Gas DieselPAHs (as B(a)P)Benzo(a)anthraceneBenzo(a)pyreneBenzo(b)fluoranthreneBenzo(k)fluoranthreneChryseneDibenz(a,h)anthraceneIndeno(l,2,3-cd)pyrene


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Table 8.lC-2HBRPWarts i la Reciprocat ing Engine Cancer Risk AssessmentRev 02/08Average annual hoursI

AmmoniaPropyleneAcetaldehydeAcroleinBenzene1,3-ButadieneDiesel PMEthylbenzeneFormaldehydeHexaneNaphthalenePAHs (Note 1)Toluene

o f D i e s e l f u e l firins 520.5 total , a l l enginesDerived (OEHHA) Method Average FI I ICancer Risk Modeled Cancer Risk ModeledAnn ual Average Mod el Input Contribution to Mod el Input ContributionEmissions Per Unit Risk (per uglm3 Cancer Risk Unit Risk (per uglm3 to Cancer

per uglm3 in one million per uglm3 in one million4.4

I ~ i s krom Diesel Firing 5.4 1 3.7 1in one million I in one m illion


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Table 8.lC-3HBRPCalculation of Modeling Inputs and HHls for Wartsila Reciprocating Engine Acute and Chronic R isk AssessmentRev 02/08

CompoundAmmoniaPropyleneAcetaldehydeAcroleinBenzene1 3-ButadieneDiesel PMEthylbenzeneFormaldehydeHexaneNaphthalenePAHsTolueneXylene

0.2436 3.13E-04 7.62E-05 1.13E-020.0576 -- - -5.637E-03 .- - -6.292E-04 5.26E+00 3.31E-03 4.92E-012.395E-03 7.69E-04 1 ME 46 2.74E-043.909E-03 -- - --- -- - -7.573E-04 -- - -4.1 81E-02 1.06E-02 4.43E-04 6.59E-021.207E-02 -- - -2.792E-04 -- - -2.278E-07 -- - -2.573E-03 2.70E-05 6.95E-08 1.03E-056.900E-03 4.55E-05 3.14E-07 4.67E-05

Total = 3.83E-03 0.57

0.2654 3.1 3E-04 8.31 E-05 1.24E-020.0317 -- - -2.853E-04 -- - -8.798E-05 5.26E+00 4.63E-04 6.89E-028.305E-03 7.69E-04 6.39E-06 9.50E-04-- - - -4.905E-01 -- - -

-- -- - -1.809E-03 1.06E-02 1.92E-05 2.85E-03

-- -- - -1.340E-03 -- - -5.107E-06 -- - -3.075E-03 2.70E-05 8.30E-08 1.24E-052.204E-03 4.55E-05 1.00E-07 1.49E-05

Total = 5.72E-04 0.1 1

Chronic Health ImpactsAnnual HHI Model ModeledAverage HARP Input (per ContributiorEmissions, Chronic HI uglm3 per to Chronic

gls (per uglm3) gls) HHI

Acute Health Impacts, Natural Gas ModeMax Hourly Acute HHIEmissions HARP Model lnput ModeledPer Engine Acute HI (per uglm3 Contribution

gls (per uglm3) per gls) to Acute HHI5.00E-033.33E-041.11E-011.67E+011.67E-025.00E-022.00E-015.00E-043.33E-011.43E-041.11E-01--3.33E-031.43E-03

Total =

Acute Health Impacts, Diesel ModeMax Hourly Acute HHIEmissions HARP Model lnput ModeledPer Engine Acute HI (per uglm3 Contribution

gls (per uglm3) per gls) to Acute HHI


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Table 8.1C-6HBRPSummary of Modeling lnput Values for Supplemental Screening HRARev2/08

All modeling input values are in units of per uglm3

Model Inputs

UnitWartsila Reciprocating Engines (per engine)Black start Diesel engineDiesel fire pump engine

Acute HHIInput, Gasfiring (peruglm3 per gls)3.83E-0300

acute gas, chronic and canceracute liquid fuel only

Stack Parameters

AveragePointEstimate(Res)

1.512E+001.085E-021.333E-02

DerivedOEHHAMethodCancer Risk(Res)

2.1 97E+001.574E-021.934E-02

Acute HHIInput, Dieselfiring (peruglm3 per gls)5.72E-0400

Wartsila Reciprocating Engines (Case 1G)Wartsila Reciprocating Engines (Case 5D)Black start Diesel engineDiesel fire pump engine

Chronic HHIInput (peruglm3 pergls)

2.01 3E-027.587E-069.323E-06

ExhaustStack Diam Tem p Exhaust(m) Stack Ht (m) (deg K) Velocity (mls)1.620 30.480 663.5561.620 30.480 599.1110.152 3.028 769.61 10.127 12.192 838.556

27.15218.22387.07344.856


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Attachment CControl of DPM by Oxidation Catalysts


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Attachment 1Washington State University Extension Energy Program

Diesel Oxidation Ca talystA diesel oxidation catalyst (DOC) is a flow through device that consists of a canister containing ahoneycomb-like structure or substrate. The substrate has a large surface area that is coated with an act ivecatalyst laye r. This layer con tains a small, well dispersed amount of precious metals such as platinum orpalladium. As the exhaust gases traverse the catalyst, carbon monoxide, gaseo us hydroca rbons and liquidhydrocarbon particles (unburned fhel and oil) are oxidized, thereby reducing harmful em issions.About 30 pe rcent of the total particulate matter (PM ) mass of diesel exh aust is attributed to liquidhydrocarbo ns, or soluble organic fraction (SOF). (See Ref. 1.) Under certain ope rating conditions, DOCShave achieved SOF removal eficien cies of 80 to 90 percent. (Refs. 1, 2) As a result, the reduction inoverall PM emissions from DOC use is often cited at 20 to 50 percent. Actual emission reduc tions varyhowever, as a result of en gine type, size, age, duty cycle, condition, mainten ance procedures, baselint:emission s, test procedu re, product manufacturer and the fuel sulfhr level.EmissionsIn their 1 999 review of heavy-duty diesel retrofits, the U.S. Environmental Protection Agency summsuizedemission s data for 60 heavy-duty diesel two and four stroke engines utilizing DOC technology (Ref. 3).The following tabl e presents these results, which ranged from 19 to 5 0 percent reduction in total PM, withan average PM reduction of 33 percent.

Table 1Diesel Oxidation Catalyst Use in Heavy Duty Diesel

In developing the C alifornia Diesel Risk R eduction Program, the Ca lifornia Air Resources Board (CA.RB)also reviewed a number of products and technologies that were reported to reduce diesel particulateemission s.(Ref. 2) While much of this information was based on m anufacturer provided data, it provides areasonab le summary of DOC technology at that time. The PM reduc tions identified are sim ilar to thosereported by EPA's 1999 study of diesel retrofit technolog ies. CARB reported achievab le emissionreductions resulting from DOC use ranging from 16 to 30 percent depend ing on product and test cyclt:. Asummary of the CA RB analy sis is presented in T able 2.

StudylreportUrban Bus and Engelhard DataSAE 960134SAE 970186SAE 932982SAE 950155London Bus Repo rt -MBK 961 165Engelhard Report-980342;APTA Report

Table 2Diesel Oxidation Catalyst PM Emission Test Resutts

PM Reductions38% avg.-two stroke; 27% avg.-four stroke32.8% avg. (2-two stroke; 5-four stroke)24% avg. (5-twostroke; 5-four stroke)44-60% (four stroke)32-41% (two stroke)45% (6-four stoke)49% (avg for three catalysts)19-44% (two stroke)

Engine type PM ControlEfficientIS 0 8 178-D2 Ford-150 hIS 0 8178-D2 Ford-1 50 h 21%8-mode 1979 Deutz F6L- 16%

R-99-014, June 1999.Source: Heavy-Duty D iesel Emission Reduction Project RetrofitRebuild Component, US EPA, EPA420-


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Washington S tate University Extension Energy Program

1 280 HpFTP 1 1998 DDC Series 60 1 5 separate

steady- stateTransient cycle-bulldozerFTP

/ 27%.Source: Diesel PM C ontrol Technologie s-Appen dix IX, California Air Resources Board,October, 2000.A number of other studies also docum ent the effectiveness of DOCs in reducing PM emissions, with 13Memission reductions of 23 percent or more. (Refs. 4 3 ) However, emission results will vary and retrofitdevice performance should be verified. To date, the EPA has verified PM reduction s of 25 percent for threemanu facturers of D OCs. Verification data is ava ilable ath~://www.e~a.~ov/otaa/retrofit/retroverifilist.htmalifornia also provides a list of verified DOC S, thttp://www.arb.ca.~ov/diesel/verifieddevices/verdev.htm.

912WCummins TD-25G450 Hp1992 Cummins L-10

Cost

24%30%

The initial cost of DOCS will vary with engin e size, application, and sales volume . CARB reported costsranging from $2,100 for a 275 horsepower engine, to as much a s $20,000 for a 1,400 hp engine.(REF.2) A1999 study of diesel particulate control devices for the underground mining ind ustry indicated a cost of $8to $12 per horsepower for DOCs, while the Manufacturers of Em issions Controls Association (MECA )recently reported DOC costs of $425 to $1,150 per device. (Ref. 5 ,6 ) The Everett School District inWashington State is currently paying $2,500 per DOC for school bus retrofits. (Ref. 7) DOC co sts forheavy duty construc tion equipment retrofits in Mass achusetts are ranging from $1,500 to $3,000. (Ref 8)An oxida tion catalyst retrofit system co nsists of either an in-line engine m uffler replacem ent or an add-oncontrol device. The size of the DOC w ill need to be matched to engine displacement and the exhau stsystem. Installation can take as little as 1% hours to 3 or 4 hours depending on the application, withcorresponding costs of $170 to $500. (Ref. 2,4) MECA repo rts that oxidation ca talys ts require very littlemainten ance, do not increase engine fuel use, shorten engine life or adversely affect vehicle drivab iliiy. TheCARB reports annual maintenance w st s of $64 to $712 per year for DOC S can be expected, based on theneed to thermally clean the device from on e to as many as four times per year. (Ref. 2) The MassachusettsDiesel Retrofit Program has retrofitted more than 120 diesel construction equipm ent engines with DOCSand has experienced no additional maintenance costs over the first three years of operation. (Ref. 8)Other issuesOxidation catalysts have a long history of performance. Retrofit of DOC S has been under way for morethan 20 years in the off-road vehicle sec tor, most notably in the unde rground mining industry, with ov er250,000 engine retrofits. An addition al 20,000 DOCS have been installed on buses and highway trucks inthe United States and Europe since 1995, with several thousand more installed in Asia and other parts ofthe wo rld. DOCS can be specified for most new engine purchases and will become a standard feature fbrnew engines by 2004 or earlier.For the most part, DOC retrofit app licatio ns are less restrictive than diesel particu late filter techno logies.This is due in part because a D OC op erates as a flow through d evic e with the catalytic reaction occurriingon the surface of the device . As a result, DOCS are less impacted by exhaus t loading than particu late filters,and can work well with older, higher emitting engines. (Ref. 9)In gen eral, DOCS also operat e well within the normal ex haust temperatures of a die sel engine. (Ref. 9)1However, elevated exhau st temp eratures, such as those sustained near peak torqu e, may adversely affe:ctDOC performance in the presence o f high sulfur concentrations. (Ref. 10) At higher temperatures, catalysts


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Washington State University Extension Energy Programcan oxidize sulfur dioxide to form sulfat e particulates (sulfuric acid). Therefore, higher sulfur fuels canincrease total particulate matter em issions and may offset soluble organic fraction emissions reductions.Although DOCs can be d esigned or tailored to operate under high sulfur concentrations, the use of lowersulfur fuels should improve the devices particulate reduction efficiency. (Refs. 2,5,9). As a result, someman ufacturers recommend a maximum su lfur content of 500 parts per million or less to enhance DOCdurability and performance. (Ref. 2) To minimize the effect of sulfate formation on DOC performan ce andmaximize D OC reduc tion efficiency, CARB staff have suggested the use o f ultra-low sulfur diesel fuc:ls of15 ppm. (Ref. 1)Manufacturers claim that the useful life of the device will vary with the application and can rang e from4,000 to 10,000 operating hours.(Ref. 2) Som e manu facturers suggestthe useful life of the dev ice is consistent with the rebuild cycle of the assoc iatedengine, and should be changed acco rdingly. The Big Dig project in Mass achusetts retrofit more than 1120construction vehicles. They are currently examining a select number of these dev ices after three years ofoperation, and expect to get an additional hvo to three years before replacement. (Ref. 8)DOCs may su ffer thermal degrada tion when exposed to temperatures above 650" C (1 200F) forprolonged periods of time. Diesel engines have intrinsically cool exhaust gases and thermal ca talystdeterioration is not likely to take place under normal op erating conditions. (Ref. 9) Several chemicalelements, such as phosphorous, lead and heavy metals, may also damage som e catalysts. Som e of theseelem ents may be contained in eng ine lube oil. To avoid this possibility, low lube oil consum ption and theuse of low-phosph orous oils may be required for some catalysts. Although DOCs im pose additionalexhau st gas flow restrictions of 4 to 11 inches of water column this appears to be within the normal rangeof engine manufactu rer specifications. (Ref. 2) As a result, DOCs do not.ap pear to affect original enginewarranties. (Ref. 2,8)References

1. California Air Resource Board Staff Report, Inirial Statement of Reasons for Prop osed R ep ia ti onfor the Yerijication Procedure for In-Use Strategies for Controlling Emissio nsfio m DieselEngines-Appendix B. Diesel Engine Emission Control Tech nologies, March 29,2002 .2. Ca lifornia Air Resou rce Board, Diese l PM C ontrol Technologies. Appendix IX, October 2000.3. U.S Environm ental Protection Agency, Heavy-Dury Diesel Emission Reduction ProjectRetrojiURebuild Compo nent, EPA420-R-99-014, June 1999.4. Construction Equipment Retrojit Project- Summary Report, Northeast S tates for Coordinated AirUse Management.5. Diesel Emission C ontrol Strategies Available to the Undergr ound Mining Industry, ESIinternational, February 24, 1999.6. Diese l Exhaust Retrojit Programs-Available C ontrol T echnologies and Retrojit ProgramConsiderations, Manufacturers of Emission C ontrols Association, Waterfront Diesel EmissionsConference, Long Beach, C alifornia, October, 25,2001.7. Personal communication, Brian Higginbotham, Durham School Services, September, 2002.8. Personal comm unication, Coralie Cooper, Northeast States for Coordinated Air Use Management,September, 2002.9. Personal communication, Marty Lassen, Johnson Mathey, September 2002.10 . U.S. Department of Energy, Diesel Emission Con trol-~& r ~ ff ec ts rojects Summary, June2001.


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Attachment 2

Description of a Diesel Oxidation Catalyst

. OC 's are typically flow through designs. he design is composed of the followingelementsCatalyst wash coat- Base Metal Oxide andPrecious MetalSubstrate- ceramic or metallicCanning - separately as a converteror in the muffler

How the DOC FunctionsThe catalyst interacts with the exhaust as i t passesthrough the converterThe Catalyst causes the particulate to burn at Sobsfmtenormal exhaust temperatures. Wash coatI /The DOC burns the gaseous HCand CO emissions, and the lubeoil, unburned fuel and carbon sootof the TPM


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Typical DOC Performance

Total Particulate Matter Reduction of 25% to50%Hydrocarbon reduction of more than 50%Carbon Monoxide reduction of more than 40%

DOC Technology Diesel Emissions -OCEmission Reductions

TPM HC COI OC-~S N m c u m * ~-10 t*sz EC ooaWDZ o m 1


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DOC Field Performance

ConclusionsIf ARB wants some particulate reductionfor all vehicles a 30% minimum is to highA properly sized DOC can obtain 25% TPMreduction on diesel enginesThe lower the sulfur in the fuel the greaterthe ability to o f the DOC to reduce TPMemissionsThis technology is proven and availablefor all on and of f road diesel engineapplications


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Attachment 3Local Govt/School BusL iesel Workshops (LCLEANA. etrofit Program onferences

HomeAbout C lean Air Fleets Emission Control TechnologyClean Yellow Fleets for BlueSkies ProgramSmartWay PartnershipDiesel Engine TechnologyEmission Control TechnoloavAlternative FuelsIdl ing Reduction Strategies- - -Emissions Standards -Colorado's D iesel I IMProgramOff-Road Diesel VehiclesCompleted Recognit ionProgram2003: Clean DieselConferenceNews &om

There have been tremendous developments in the design and application of emission controltechnologies in the last decade to substantially reduce levels of particulate matter (PM), carbonmonoxide (CO), nitrogen oxide (NOx), and hydrocarbon (HC) pollutants. The two mostcommon technologies- diesel particulate filters (DPF) and oxidation catalysts (DOC)-effectively control the levels of pollutants in the exhaust on their own or when used together.For example, a diesel oxidation catalyst can lessen the formation of particulalte matter prior tothe exhaust passing through a particulate filter, thereby increasing the perfonnance andlongevity of the filter. Additional technologies are designed to control specific pollutants, suchas NOx.While some of these technologies are affected less by the sulfur content of diesel fuel, allperform better at reducing emissions when used with ultra-low sulfur diesel fuel (ULSD), whichhas a sulfur content of less than 15 ppm. For example, diesel oxidation catalysts and someDPFs can reduce CO, HC, and PM emissions with fuels that contain sulfur levels greater than15 ppm while catalyst-based DPFs are more sensitive and are more effective with ULSD. (Seethe insert on "Alternative Fuels" for more information.)Costs for individual technologies vary. This insert cites costs from an independent cost surveyconducted in November 2000 by the Manufacturers of Emission Controls Association (MECA).Generally, the larger the engine being retrofitted, the more expensive the device. However,higher sales volumes will begin to lower the costs of these technologies. Given the recentmarket penetration, costs should begin to decrease. Prices cited in association with specifictechnologies and their pollution reduction potential are provided by the U.S. EnvironmentalProtection Agency (EPA). The reader is encouraged to contact individual marlufacturers orexact costs.Diesel Particulate Filters [DPF)

/ Base Metal Oxidizing PM Filter $6.5-/ -- I 80% /50%150%) loK 1NOxHighly Oxidizing Precious Metal PM $6.5-1 Filter / $jo >90%/90%190%1 loK I

PM

I ( NOX PM I HC I co price 1I Base Metal Oxidation Catalyst I -- 1 10-30% 1 50% 1 50% $1-2K IDiesel particulate filters (DPFs) are one class of emission control technologies; that lower PMemissions. By trapping the particulates as the exhaust gas passes through the! filter, DPFs areable to achieve PM reductions of 80- 90 percent. Numerous studies have documented theeffectiveness of DPFs in both on- and off-road applications. The systems are relatively easy tomaintain, but do require users to monitor their condition and occasionally remove the filter,blowing out the ash and replacing it.

- - - - --Precious Metal Oxidation Catalyst --

Fuel sulfur content plays a key role in the performance of DPFs since it has a (direct mpact onthe level of particulate matter in the exhaust. Numerous studies have found that DPFs,regardless of their manufacturer, achieve higher PM emission reductions with the use of ultra-low sulfur diesel fuel.

- -->20-40%


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Two DPF products - Engelhard's DPX Catalyzed DPF and the Johnson Matthey ContinuouslyRegenerating Technology (CRT) Particulate Filter- educe PM, CO, and HC by 60 percent asverified - but are capable of reducing emissions by 80 - 90 percent. Both tec.hnologies areverified by EPA's National Voluntary Diesel Retrofit Program -which tests ar~dalidatestechnologies for fleet managers and operators- or their performance. These! products areverified with ULSD. Today's technology could be utilized in many off-road applications butrequires active regeneration echnology being developed for on-road use to rnake it applicableto all off-road applications. DPF retrofit programs for trucks and buses are underway inCalifornia and New York City, where the city plans to retrofit its 3,500 buses with DPFs by theend of 2003.Diesel Oxidation Catalysts (DOC)Diesel oxidation catalysts (DOCs) are a section of the exhaust system coated with metals thattrigger chemical reactions which breakdown pollutants (CO, HC, PM) into harmless gases,when engine exhaust passes through it. Since 1995, more than 500,000 trucks and buses havebeen retrofitted with DOC systems.On- and off-road applications of DOCs are virtually maintenance ree, requiring only periodicinspections. DOCs also work to improve the effectiveness and performance of DPFs, byattracting excess soot from the exhaust before it passes through the filter. The cost of dieseloxidation catalyst devices range from several hundred to several thousand dc~llars er devicedepending on engine size, sales volume, and whether the installation is a muffler replacementor an in-line installation. MECA's 2000 survey reported that average diesel oxidation catalystcosts ranged from $465 to $1,750 per vehicle. The majority of devices are designed to replacethe muffler and installations typically take less than two hours.Like DPFs, DOCs are also affected by sulfur. The sulfur content of diesel fuel is critical toapplying catalyst technology, as the reaction caused by the catalysts rely on the sulfur contentand the temperature of the exhaust gases.NOx Reduction TechnoloqiesThe first verified system to reduce NOx and PM is a NOx reduction catalyst. This systemcombines a NOx catalyst with a particulate filter or oxidation catalyst to provide additional PMreductions. The Longview system from Cleaire (and offered by Fleetguard Emission Solutions)is verified to reduce NOx by 25 percent and PM by 85 percent.In addition to the exhaust gas recirculation(EGR)echnology to lessen NOx during thecombustion process (see the insert on "Advances in Diesel Engine Technolog:yWor moreinformation), post-combustion emission controls for NOx include selective catalytic reduction(SCR) and NOx adsorber technologies.SCR devices have been used for years to control NOx from stationary sources and are nowbeing applied to mobile sources to cut the pollutant by over 70 percent. Unlike DOCs, the SCRsystem requires the addition of a reductant (typically urea or ammonia) to convert NOxpollutants to nitrogen and oxygen. Based on the oxidizing metals used in the SCR, additionalpollutant reductions can be achieved. (See the insert on "Off-Road Heavy-Duty DieselVehicles" for more information.)NOx adsorber catalyst technology is also undergoing extensive research and development inanticipation of the 2007 on-road, heavy-duty diesel engine regulations. Researchers havedemonstrated the ability of NOx adsorbers to control up to 90 percent or more of NOxemissions over a broad temperature range.NOx adsorbers act to store NOx emissions during lean engine operation and release the stored


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NOx by periodically creating a rich exhaust environment by either engine operation or theinjection of a reductant in the exhaust stream. While EPA estimates that the technology can cutNOx (as well as HC and CO) by more than 90 percent, it is still largely in the research anddevelopment phase for on-road applications.Crankcase Emission ControlIn the majority of turbo-charged diesel engines, the crankcase breather is vented to theatmosphere often using a downward directed draft tube, therefore allowing a :substantialamount of PM to be released into the atmosphere. One solution to this emissions problem isthe use of a multi-stage filter designed to collect and return the emitted lube oil to the engine'ssump or a CCV system (available from Fleetguard). These systems allow filtered gases toreturn to the intake system, balancing the differential pressures involved and allowing thesystems to eliminate crankcase emissions. EPA has verified one manufacturer's crankcasefiltration system. In addition to the Donaldson closed crankcase filtration system's ability tolower crankcase emissions, it also reduces PM emissions by 25 - 32 percent and CO by 14 -18 percent, according to EPA.Additional Technolonv PotentialThe California Air Resources Board recently verified the use of a diesel engine retrofittechnology that simultaneously achieves reductions of at least 85 percent in PM and 25 percentin NOx emissions. The system produced by Cleaire Advanced Emission Controls is actually acombination of a lean NOx catalyst and a diesel particulate filter. The system lias been verifiedfor use on specific on-road diesel engines operating on ultra-low sulfur diesel fuel. In addition toDOC technology used to treat exhaust gases, EPA estimates that catalysts included in dieselfuel for commercial use will cut NOx up to 10 percent, PM up to 33 percent, arid HC and CO upto 50 percent during the combustion process.The Lubrizol Corporation has developed a water-in-diesel fuel emulsion product that producesa low-emission, emulsified diesel fuel. PuriNOx reduces NOx emissions up to 30 percent andPM up to 65 percent when compared to conventional No. 2 diesel fuel. Average emissionreductions, considering data from numerous tests, indicate a NOx reduction of approximately20 percent and a PM reduction of approximately 54 percent. The application areas for fuelpowered by PuriNOx are centrally-fueled fleets, such as pick-up and delivery vehicles, urbanand school buses, waste management fleets, and agricultural, mining, and coristnrctionequipment.SourcesDieselNet- h t t ~ ~ / / w~eselnet.com/Manufacturers of Emission Controls Association - http:llwww.meca.or~U.S. Environmental Protection Agency, Voluntary Diesel Retrofit Program -www.e~a.govlotaalretrofit


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Attachment 4s%20and0/~20Settings/NLM/Local%ZOSettings/Temporary0/~2OInternet0/~2OF~ies/OLKE3/Potent~alo/~2ORetrofito/~2OTechnol~~gies~o/~2OSummary0t%20Technology%2OVerificationn/o2O0/~2OUS%2OEPA.mht Last updated on Wednmasday, August 29th, 2007.Diesel Retrofit Technology Veri f icat ion

YOU are here: PA Home Trans~ortaton and Air Ouality National Clean Diesel Cam~aian Diesel Retrofit Technoioav Verification VerifiedTechnolooieh Technical Summary

Technical SummarvRelated InformationThe following table lists information collected by EPA staff showing the potential capabilities of a variety of . ll EPA Verifiedboth curren tly available and future emissions reduction technologies. This list may not be used to provide Technologiesformal emission reduction claims for SIP purposes, compliance programs, or consent decree projects. This list ' frlonroad Engine

is intended to provide guidance in selecting appropriate technology for air quality program needs and to Technologiesprovide a general estimate of the emissions reduction capabilities of the various technologies. Actualemissions reductions, cost, fuel economy penalty will be a function of the individual applications and situations. EPA has created averification program that will officially evaluate the emission performance of technology as individual manufacturers submit their products tothe verification program. EPA will list the official performance data and associated informat ion on ourDiesel-Technoloav List.

Summary of Potential Retrofit TechnologiesTechnology Emission Reduction

NOx PM HC CO-- 10-30 50 50

Price($11-2K

1-3K

6.5-10K

6.5-10K

6.5-10K

8-10K

--

O.Ol/gal

SulfurTolerance( P P ~ )


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benefit formaldehydeSelectiveCatalyticReduction


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Attachment 5 Contact UsHonie I Products Case Studies 1 Services I Technology A b o ~ q edia Center1

S I I - I . 1

Off-Road VehiclesConstructionMaterial HandlingMiningSmall Utility Engines

Stationay EnginesGas CompressionPorver Generati on

On-Road Vel~icle sBuses and Truc ksXndtistrial Processes

Diesel Oxidation CatalystOxidat ion C:atalystParticulate FilterSelect ive Catalytic Reduc.'Three-Way Catalyst

Contact UsFAQs

Diesel Oxidation Catalyst. earch:)

dProductsCatalytic C ~~nv erte rsCustomCatalytic Co'nverters-StandardCatalytic Converters -Stationary E.ngines(< 700 hp)Catalytic Converters -Stationary Engines (> 3000 hp)Catalytic Converters -Stationary Engines (700 - 3000hp)Catalytic Converters 8Catalytic Mufflers -Smal lEnginesCatalytic Muff lers - Heavy DutyCatalytic Mufflers - Light DutyCatalytic Muf flers - ModularCatalvtic Mufflers - Stationarv~ n ~ i n e s< 700 hp)Catalytic Mufflers - StationaryEngines (700 - 3000 hp)Diesel Particulate Filter - Flow-Through

The diesel oxidation catalyst (DOC) is effective for the control of carbon monoxide (CO), hydrocarbons(HC), odor causing compounds, and the soluble organic fraction (SOF) of particulate matter (PM,,).

Orde r Lit era tu re Typical Conversion Efficiencies

Less than 50 ppm sulphur in diesel fuel is required for PM,, conversionReactions

1Carbon Monoxide ( c 0 + % 0 2+ COP 1(1)1Gas Phase HydrocarbonsLiquid Phase Hydrocarbons (SOF)

Privacy Policy I Terms of UseCopyright 2005 - 2006 DCL International nc. All Rights Resewed.

CmHn+ (m + nl4) 0, + m CO, + nI2CmHn+ (m + nl4)0, m CO, + n12 HO

Aldehydes, Ketones, etc.- -

CHnO + (m + nI4 - 0.5)0, + m CO,


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Attachment 6

Emission Off-Road Diesel EquipmentControl Emiss ion Contro l Technologies for Of f -Road Diesel EquipmentTechnology Catalyt ic ConvertersOverview >>Autos, SUVs 8 Trucks >> Die sel Oxidation Catalysts: In most applications, a diesel oxidation catalyst consists of a stainlesssteel canister that contains a hone ycomb structure called a substrate or catalyst support. ThereTrucks 8 Buses >> are no m oving parts, just large amoun ts of interior surface area. The interior surfaces .are coatedwith catalytic metals such as platinum or palladium. It is called an oxidation ca talyst because theOff-Road Diesel Equipment device conve rts exhaust gas pollutants into harmless ga ses by mea ns of chemical oxisdation. In>> the case of diesel exhaust, the catalyst oxidizes CO, HCs, and the liquid hydrocarbons adsorbedon carbon p articles. In the field of mobile source emission control, liquid hydrocarbons adsorbedOff-Road SI Equipment >> on the carbon particles in engine exhaust are referre d to as the soluble organic fraction (SO F) --the soluble pa rt of the particulate matter in the exhau st. Diese l oxidation catalysts are efficient atAlternative Fuel I Advanced converting the soluble organic fraction of diesel particulate matter into carbon dioxide and water.Technology Vehicles >>

Oxidation catalyst retrofits have proven effective at reducing particulate and smoke err~iss ions nolder vehicles. Under the U.S. EPA 's urban bus rebuildlretrofit program, five manufacturerscertified diesel oxidation catalysts as providing at least a 25 percent reduction in P M elmissions forin-use urban buses. Ce rtification data also indicates that oxidation catalysts achieve substantialreductions in CO an d HC em issions. Currently, under the ARB a nd EP A retrofit techncllogyverification processes, several technology m anufacturers have verified diesel oxidation catalystsas providing at least a 25 percent reduction in PM emissions.earch our Si teIFigure. DOC

SCR System s: A Selective Catalytic Reduction (SCR) system uses a metallic or ceramic wash-coated catalyzed substrate, or a homo geneously extruded catalyst and a che mical reductant toconvert nitrogen oxides to molecular nitrogen and oxygen in oxygen-rich exhaust streams likethose encountered with diesel engines. In mob ile source applications, an aqueous urea solution isusually the preferred reductant. Upon thermal decomposition in the exhaust, urea decomp oses toammonia which serves as the reductant. In some cases amm onia has been used as the reductantin mobile source retrofit applications. As exha ust and reductant pa ss over the SCR c atalyst,chemical reactions occur that reduce NOx em issions to nitrogen and water. SCR catalysts can becombined with a particulate filter for combined redu ctions of both PM and NOx.Open loop SCR systems can reduce NOx emissions by 75 to 90 percent. Closed loop systems onstationary engines can ach ieve NOx reductions of greater than 95 percent. SCR systems are alsoeffective in reducing HC emissions up to 80 percent and PM emissions 20 to 30 percent. Like allcatalyst-based emission control technologies, SCR p erformance is enhanced by the us e of lowsulfur fuel.


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Erhnust Pipe

Oval .WRCRDPF A

Figure. SCR systemLean NOx Catalysts:Controlling NOx emissions from a diesel engine is inherently difficult becausediesel engines are designed to run lean. In the oxygen-rich environme nt of diesel exhaust, it isdifficult to chemically reduce NO x to molecular nitrogen. The conversion of NOx to molecularnitrogen in the exhaust stream requires a reductant (HC, CO or H2) and under typical engineoperating co nditions, sufficient quantities of reductant are not present to facilitate the cronversion ofNOx to nitrogen.Some le an NOx catalyst (LNC) systems inject a small amount of diesel fuel or other reductant intothe exhaust upstream of the catalyst. The fuel or other hydrocarbon reductant serves as areducing agent for the catalytic conversion of NOx to N 2. Other systems operate pass ively withoutany added reductant at reduced NOx conversion rates. A lean NOx catalyst often in cl ~~ de sporous material mad e of zeolite (a micro-porous mate rial with a highly ordered channel structure),along with either a precious m etal or base me tal catalyst. The zeolites provide microscopic sitesthat are fuellhydrocarbon rich where reduction reactions can take place. Without the added fueland catalyst, reduction reactions that convert N Ox to N2 would not take place because! of excessoxygen prese nt in the exhaust. Currently, peak NO x conversion efficiencies typically are around10 to 30 percent (at reasonable levels of diesel fuel reductant consumption).

Figure. LNCLean NOx Traps:Another type of catalyst being developed for diesel engines are known as leanNOx traps (LNT) becau se they function by trapping the N Ox in the form of a m etal nitrate duringlean operation of the engine. The most common compound used to capture NO x is BariumHydroxide or Ba rium Carbonate. Under lean air to fuel operation, NO x reacts to form NO2 over aplatinum catalyst followed by reaction with the Barium compound to form B aN 03 . Following acertain amount of lean operation, the trapping function will become saturated and must beregenerated. This is comm only done by operating the engine in a fuel rich mo de for a brief periodof time to facilitate the conversion of the barium com pound b ack to a hydrated o r carbonated formand giving up NO x in the form of N2 or NH3. LN T catalyst can be combined with a zeolite basedSCR catalyst to trap ammonia and further reduce NO x via a selective catalytic r edu ctio~ ieactionto nitrogen.

Part iculate Fi l tersDiese l particulate filters rem ove particulate matter found in diesel exhaust by filtering exh aust from the


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engine. Diesel particulate filters or (DPF) can come in a variety of types depending on the level of filtrationrequired. The simplest form of part iculate removal can be achieved using a DOC as discussed as part ofthe diesel catalyst section. Diesel particulate filters can be either partial, flow through devices or wall flowdesigns which achieve the highest filtration efficiency.6 Parfial or Flow Through Filters: The first level of filtration can be achieved using a parl:ial or flow

through particulate filter. In this type of device, the filter element can be made up of a variety ofmaterials and designs such as, sintered metal, metal mesh or wire, or a reticulated metal orceramic foam structure. In this type of device the exhaust gasses and PM follow a tortuous paththrough a relatively open network. The partial filtration occurs as particles impinge on the roughsurface of the mesh or wire network of the filter element. Partial filters can be catalyzed oruncatalyzed and are less prone to plugging than the more commonly used wall flow filtersdiscussed below.

Figure. FTF

6 High E ff iciency Wall Flow Filters: In order to meet the stringent particulate emissions that arerequired for diesel light duty vehicles starting with the 2007 model year, the highest eff~ciencyparticulate filter is required. These are commonly made from ceramic materials such a:; cordierite,aluminum titanate, mullite or silicon carbide. The basis for the design of wall flow filters is ahoneycomb structure with alternate channels plugged at opposite ends. As the gasses passes intothe open end of a channel, the plug at the opposite end forces the gasses through the porous wallof the honeycomb channel and out through the neighboring channel. The ultrafine porclusstructure of the channel walls results in greater than 85% percent collection efficiencies of thesefilters. Wall flow filters capture particulate matter by interception and impaction of the solidparticles across the porous wall. The exhaust gas is allowed to pass through in order to maintainlow pressure drop.Since a filter can fill up over time by developing a layer of retained particles on the inside surfaceof the porous wall, engineers that design engines and filter systems must provide a means ofburning off or removing accumulated particulate matter and thus regenerating the filter. Aconvenient means of disposing of accumulated particulate matter is to burn or oxidize t on thefilter when exhaust temperatures are adequate. By burning off trapped material, the filter iscleaned or "regenerated" to its original state. The frequency of regeneration s determined by theamount of soot build-up resulting in an increase in back pressure. To facilitate decomposition ofthe soot, a catalyst is used either in the form of a coating on the filter or a catalyst added to thefuel. Filters that regenerate in this so-called "passive" fashion cannot be used in all situ,ations. Theexperience with catalyzed filters indicates that there is a virtually complete reduction n odor and inthe soluble organic fraction of the part iculate. Despite the high efficiency of the catalyst, a layer ofash may build up on the f ilter requiring replacement or servicing. The ash is made up 0.1 inorganicoxides from the fuel or lubricants used in the engine and will not decompose during the regularsoot regeneration process.In some applications or operating cycles, the exhaust never achieves a high enough temperatureto completely oxidize the soot even in the presence of a catalyst. In these instances, ar "active"regeneration system must be employed. Active regeneration utilizes a fuel burner or a resistivelyheated electric element to heat the filter and oxidize the soot. Active regeneration can beemployed either in-place on the vehicle or externally. During external regeneration, the filter is


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removed from the vehicle and heated in a controlled chamber

PMCOHCsPAHsSO:NO

Trapped

PluggedCells

CO:H:OSO:S O

Figure. DPFSensor Technologies

Temperature Sensor: Temperature sensors are used for two purposes: The first is as a warningsystem, typically on obsolete oxidation-only catalytic converters. The function of the sensor is towarn of temperature excursions above the safe operating temperature of the catalytic converter.However, modern catalytic converters are not as susceptible to temperature damage. IManymodern three-way Platinum-based converters are able to handle temperatures of 900 (degrees Csustained, while many modern three-way Palladium-based converters are able to hanclletemperatures of 925 degrees C sustained. Temperature sensors are also used to mon~torhetemperature rise over the catalytic converter core.Oxygen Sensor: Oxygen sensors are part of the closed loop fuel feedback control system,associated with modern three-way catalyst emission control systems on gasoline engines. Theclosed loop fuel feedback control system is responsible for controlling the airlfuel ratio of thecatalytic converter feed gas. During the closed loop operation, the electronic control module(ECM) keeps the airlfuel ratio adjusted to around the ideal 14.7 to 1 ratio. Signal from the oxygensensor is used to determine the exact concentration of oxygen in the exhaust stream. From thissignal, the ECM determines whether the mixture is richer or leaner than the ideal 14.7 ro 1 airlfuelratio. If the airlfuel ratio deviates from its preprogrammed swings, catalyst efficiency decreasesdramatically, especially for NOx reduction. The oxygen sensor informs the ECM of neededadjustments to injector duration based on exhaust conditions. After adjustments are made, theoxygen sensor monitors the correction accuracy and informs the ECM of additional adjustments.The oxygen sensor is also an integral part of the onboard diagnostic (OBD) system wh~chmon~torsthe proper functioning of the emission control system of the vehicle. If the sensor detects oxygencontent of the exhaust that is outside the specified range of the engine calibration, it will trigger theengine light to come on in the instrument cluster.NOx Sensor: NOx sensors represent state of the art technology that can be applied to gasolinelean burn engines as part of a broader engine control or diagnostic system used to insure properoperation of the NOx emission control system. These sensors can be incorporated independent ofthe NOx emission control technology used on the vehicle and their function is primarily to monitorthe NOx conversion efficiency of the catalyst. The sensors can work as part of a feedback loop tothe control unit on the emissions system to make real time adjustments and optimize NlOxconversion. The principle of operation of one type of NOx sensor is based on proven sc~lidelectrolyte technology developed for oxygen sensors. The dual chamber zirconia sensing elementand electro-chemical pumps work in conjunction with precious metal catalyst electrodes to controlthe oxygen concentration within the sensor and convert the NOx to NO and nitrogen. The sensorsends output signals in volts that are directly proportional to ppm NOx concentration. The sensorscan be incorporated upstream and downstream of the catalyst, for example, to provide .a feedbackcontrol loop to the ECU of the emissions system. The ECU can than make adjustments to optimizeNOx conversion performance. The ECU can than make adjustments to optimize NOx conversionperformance. In the case of SCR technology, feedback can also be provided to the urea dosingsystem whereas in the case of lean NOx trap technology a feedback loop could signal tlheregeneration of the trap.

Thermal Management Strategies


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The m ajority of emissions from today's gasoline and diesel engines o ccur during cold start before thecatalyst can achieve optimum operating temperatures. Exhaust system manufacturers have been workingtogether with catalyst companies to develop w ays to heat up the catalyst as quickly as possitlle. Thegreatest impa ct came from the introduction of close coupled catalysts (CCC ) to supplement tlie existingunderfloor systems in the mid-1990. This positioned a smaller catalytic converter close to the exhaustmanifold to allow rapid oxidation of CO and hydrocarbons. The exotherm ic heat generated in the CCC bythese reactions facilitates the rapid heat up of the dow n stream, larger, underfloor, TWC . In laterdevelopments, the CCC w as sometimes formulated to b e a fully functional TWC with the underfloor unitserving as a clean-up catalyst to convert the final 10-20% of the pollutants.The beneficial impact on reducing cold start emissions via thermal management has led to numerousimproveme nts to the exhaust system compone nts up stream of the converter in order to retain as muchheat as possible in the exhaust gas es. Manufacturers hav e developed ways to insulate the exhaustmanifold and exhaust pipe. Attaching the CC C to a double walled, stainless steel exhaust pipe containingan air gap within the tube walls is probably the m ost common thermal management strategy l~ s e doday.To me et the tightest SU LEV and PZEV regulations required attention to the temperature distribution at theface of the CCC. This led to new inlet cone designs and m odification to the shape of the space in front ofthe close coupled substrate.EnginelFuel ManagementAchieving near-zero exhaust emission targets requires a systems approach. Engine manufacturers arefocusing on ways to control engin e operation to reduce engine o ut emissions as low as possible andreduce the burden on the catalysts.Approaches aimed at reducing cold start emissions involve retarding the ignition timing so a s to allowsome hydrocarbons to pass through in the exhaust and light off the catalyst sooner. Variable valve timing(VVT)s being used to introduce some fraction of exhaust gas into the combustion process and reduceHC and NO x emissions. On clean diesel engines, Exha ust Gas Recirculation (EGR) is used to diluteintake air with som e fraction of exhaust gas to low er the combustion temperatures resulting in lowerengine out NOx emissions.

Figure. Low-pressure EGR + DPFDirect injection of fuel into the cylinders rather than po rt injection has allowed better control of the air fuelratio during comb ustion and resu lted in better fuel utilization. Improved turbulence and m ixing in the intakeport of some low emission engines h ave resulted in a 24% fuel savings. Clean diesel engines havebenefited significantly from com mon rail fuel injection which allows for electronically controllecl injection atvery high pressures. Through the use of pilot and retarded injection strategies or in combination withinjection rate shaping clean diesels have achieved significant reduction in NOx over conventional dieselinjection such as p ipe-line or unit injection. Common rail and electronic injection control is very effective incarefully controlling post injection of fuel making it suitable for use with emission control devices such asparticulate filters, NOx adsorbers and lean NO x catalysts requiring brief periods of fuel rich exhaust tofacilitate regeneration of the catalyst or filter.


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Evaporative Emission ControlsEvaporative emissions are generally classified into two broad categories: HC emissions associated withthe release of vapors due to elevated ambient temperatures (diurnal losses) and HC emissionsassociated with the release of vapors during normal vehicle operation ("running losses"). Moclern light-duty gasoline vehicles have implemented a variety of approaches and technologies to reduce evaporativeemissions from these sources. In the early 1970s, carbon canisters were installed on vehicles to controlgasoline vapor losses from fuel tanks. The canister systems include purge systems to release HCsabsorbed on the carbon-based absorbent back into the combustion chamber once the engine is running.In addition to carbon canisters, other measures are being implemented on lightduty gasoline vehicles astighter evaporative emission controls have been introduced as part of the EPA Tier 2 and AR13 LEV IIprograms. New multi-layer polymer materials have been developed that have extremely low vaporpermeation rates for use in gas tanks and, fuel line connectors and seals to reduce evaporativeemissions. HC adsorber elements have been developed for use in air induction systems to reduce diurnallosses associated with fuel delivery components such as fuel injectors. These adsorber elements can bebased on monolithic carbon honeycombs or metal substrates coated with zeolitic materials th.at have ahigh affinity for HC vapors.Enhanced Combustion TechnologiesUnderstanding and controlling the combustion process is the first step in reducing engine out emissionsand reducing the burden on the emission control systems within the exhaust. Engine design i animportant part of controlling and facilitating the combustion process.In diesel engines, controlling combustion is the key approach to reducing engine out particulate emissionsby optimizing the mixing between the fuel and air. Some common ways to increase mixing is Ihroughcombustion chamber modifications o facilitate turbulent flow as well as fuel injector design to modify thespray pattern. Variable geometty turbocharging (VGT), which delivers variable quantities of pressurizedair based on driving conditions, has been effective in reducing PM emissions by maintaining leancombustion in the engine. Reducing compression ratios have been shown effective in reducingcombustion temperatures and in turn NOx emissions.Some common approaches to enhance air turbulence and improve fuel distribution within the cylindersinclude improvements to the design of fuel injectors, combustion chambers and injection ports. Someengine manufacturers have been able to achieve improvements to the combustion during colcl stalt bymaking modifications o the design of intake air control valves resulting in a 40-50% reduction in HCemissions and injection ports among others.Crankcase Emission Control TechnologiesToday, in most turbocharged aftercooled diesel engines, the crankcase breather is vented to theatmosphere often using a downward directed draft tube. While a rudimentaty filter is often installed on thecrankcase breather, substantial amount of particulate matter is released to the atmosphere. E~nissionsthrough the breather may exceed 0.7 glbhp-hr during idle conditions on recent model year engines. ForMY 1994 to 2006 heavy-duty diesel engines, crankcase PM emissions reductions provided by crankcaseemission control technologies range from 0.01 glbhp-hr to 0.04 glbhp-hr or up to 25 percent of the tailpipeemission standards.One solution to this emissions problem is the use of a multi-stage filter designed to collect, coalesce, andreturn the emitted lube oil to the engine's sump. Filtered gases are returned to the intake system,balancing the differential pressures involved. Typical systems consist of a filter housing, a pre., csureregulator, a pressure relief valve and an oil check valve. These systems greatly reduce crankcaseemissions. Crankcase emission controls are available as a retrofit technology for existing diesel enginesor as an original equipment component of a new diesel engine.


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Air FilterFigure. Crankcase emission control system

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BEFOREHE ENERGY ESOLIRCESONSERVATIONND DEVELOPMENTOMMISSIONOF TH ESTATE F CALIFORNIAAPPLICATIONORCERTIFICATIONOR THEHUMBOLDTAYREPOWERINGROJECTBY PACIFICGASAND ELECTRIC OMPANY

Docket No. 06-AFC-7PROOF OF SERVICE(Revised 10125107)

INSTRUCTIONS: Al l parties shall I ) send an original signed document plus 12copies 2) mail one original signed copy AND e-mail the document to the webaddress below, AND 3) all parties shall also send a printed electronic copy ofthe documents that shall include a proof of service declaration to each of theindividuals on the proof of service:CAI-IFORNIA EN ERGY COMM ISSIONAttn: Docket No. 06-AFC-071516 Ninth Street, MS-4Sacramento, CA 95814 -5512docket~enerqv.state.ca.usAPPLICANTJon MaringPGE245 M arket StreetSan Francisco, CA [email protected]'S CONSULTANTS*Gregory LambergProject Manager,Radback EnergyP.O. Box 1690Danville, CA [email protected] back.com

Susan StrachanEnvironme ntal ManagerStrachan Consu ltingP.O. Box 1049Davis, CA 95617

COUNSEL FOR APPLICANTScott Galati, Project AttorneyGALATI & BLEK, LLP555 Capitol M all, Suite 600Sacramento. CA 95814INTERESTED AGENCIESDoug las M. Davy, Ph.D.C H ~ M ILL project Manager Tom Luster2485 N atomas Park Drive, Suite 600 California Coastal Com mission

Sacramento, CA 958 33 45 Frem ont, Suite [email protected] San Francisco, CA 941 05-2219t luster~coastal .ca.sov

Indicates Change Revised 10125107


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Paul DidsayabutraCa. Independent System Operator151 Blue Ravine RoadFolsom, CA 95630PDidsavabutra@~caiso.comElectricity Oversight Board770 L Street, Suite 1250Sacramento, CA [email protected]

ENERGY COMMISSIONJEFFREY D. BYRONAssociate [email protected]. us

Gary FayHearing [email protected]. usJohn KesslerProject [email protected] DeCarloStaff [email protected],

Mike MonasmithPublic Adviser's Officepao@energ~.state.ca.us

JOHN L. GEESMANPresiding [email protected]

Declaration o f Service

I, Marquerite Cosens, declare that on February 6, 2008, 1 deposited the required copies of theattached PACIFIC GAS & ELECTRIC COMPANY'S SUPPLEMENTAL SCREENING HEALTHRISK ASSESSMENT in the United States mail at Sacramento, CA with first-class postage thereonfully prepaid and addressed to those identified on the Proof of Service list above. I declare underpenalty of perjury that the foregoing is true and correct.

ORransmission via electronic mail was consistent with the requirements of California Code ofRegulations, title 20, sections 1209, 1209.5, and 1210. All electronic copies were sent to all thoseidentified on the Proof of Service list above.I declare under penalty of perjury that the foregoing is true and correct.

Marguerite Cosen

Documents

2008-02-06 Supplemental Screening Health Risk Assessment TN-45277