January 3, 2012



### ERTAC Rail Emissions Inventory
Part 1: Class I Line-Haul Locomotives

Michelle Bergin, GA Environmental Protection Divisi on Matthew Harrell, IL Environmental Protection Agency Mark Janssen, Lake Michigan Air Directors Consortiu m

Acknowledgments: Robert Fronczak, Association of American Railroads Raquel Wright, Federal Railroad Administration Julie McDill, Mid-Atlantic Regional Air Management Association Patrick Davis, Mid-Atlantic Regional Air Managemen t Association Laurel Driver, US EPA, Office of Air Quality Plann ing and Support Byeong Kim, GA Environmental Protection Division

Introduction

Air protection agencies from twenty-seven states, c oordinated through the Eastern Regional Technical Advisory Committee (ERTAC) and headed by the Lake M ichigan Air Directors Consortium (LADCO), identified a need to better quantify and c haracterize rail-related emissions inventories. Traditional locomotives utilize large diesel engine s, resulting in emissions of NO
x , diesel PM, hydrocarbons, greenhouse gases, and other air pollu tants. These emissions are sometimes concentrated in areas exceeding National Ambient Air Quality Sta ndards. No cohesive nationwide railroad emission estimates based on local operations are kn own to have been made previously. Inventory development methods for locomotive emissions estima tes vary from state to state and, in general, lack the spatial or temporal resolution needed to suppor t air quality modeling and planning 1-5

.

The ERTAC Rail Subcommittee (ERTAC Rail) was establ ished with active representatives from twelve member states, three regional planning offic es, and the US EPA. The subcommittee’s goals are to (1) standardize agencies’ inventory development methods through a collaborative effort, (2) improve the quality of data received and the result ing emission inventories, and (3) reduce the administrative burden on railroad companies providi ng data.

With support from the Rail industry and assistance from the ERTAC Rail Data Workgroup (Appendix A), ERTAC Rail has developed 3 inventories of locom otive emissions (Table 1) for Class I line-haul, Shortline and Regional Railroads (Class II and III operations), and Class I railyard switchers. Becau se of the difficulty in obtaining data and differences in states’ needs for inventory years, sources from both 2007 and 2008 were utilized (Appendix B.)

The Surface Transportation Board (STB) defines Clas s I Railroads as having had minimum carrier operating revenues of $401.4 million (USD) in 2008. There are 8 Class I Railroads operating in the United States (Table 2), about 33 Regional Railroad s (Class II), and approximately 540 Class III Railroads (Shortlines) 6 . While categorized as a Class I Railroad, Amtrak w as excluded from these inventories because of significant differences in e quipment and operational characteristics. Line-hau l locomotives are usually newer, larger locomotives t hat travel long distances (e.g. between cities) whi le switcher locomotives are generally older, smaller l ocomotives that mostly operate within railyards,2

splitting and joining rail cars with varying destin ations. Shortline railroads often utilize smaller, older locomotives than Class I line-haul. Passenger and Commuter Rail (including Amtrak), industrial locomotives, and associated non-locomotive equipmen t are not included in these inventories.

This paper documents the data sources and methodolo gies used for calculating the Class I line-haul emissions inventory. Class I line-haul activities a re the largest source of rail-related emissions, wi th estimates of Class I line-haul fuel consumption tot als to be from 74 to 84% of all rail sources
combined 4, 5 . For this reason, characterizing Class I line-hau l emissions were a focal point of ERTAC Rail’s inventory development efforts. This invento ry best represents 2007 emissions and can be scaled for a few years back or forward using annual line-h aul fuel use reported to the STB. Information on ERTAC Rail, Railroad participation, the Rail indust ry, and effects of rail on air quality are availabl e elsewhere 7

.

Table 1. Summary of ERTAC Rail Inventories: U.S. Lo comotive Emissions and Fuel Use for
either 2007 or 2008*. Fuel Use** (gal/yr) Emissions (tons/yr)
NO
x PM 2.5 HC SO 2 CO NH 3 CO 2 Class I***
line-haul 3,770,914,002 754,443 23,439 37,941 7,836 110,969 347 42,305k

Class I
switcher 301,046,290 74,431 2,042 4,867 624 9,230 28 3,367k

Class II
and III 157,800,000 47,035 1,065 1,737 327 4,631 14 1,765k

*See Appendix B for a description of the year and s ource of data utilized for each inventory. **Locomotive grade diesel ***Excluding Amtrak and including work train fuel u se

Table 2. Class I Railroads, Reported Locomotive Fu el Use, and Railroad Fuel Consumption Index (RFCI) 8

.

Class I Railroads* R-1 Reported Locomotive Fuel Use (gal/yr) RFCI (ton-miles/gal) Line-Haul (2007)** Switcher

(2008) BNSF 1,393,874,954 52,497,057 883.14 Canadian National 93,830,751 12,290,022 1190.79 Canadian Pacific ***50,320,233 4,937,067 1096.28 CSX 514,687,186 53,717,674 963.81 Kansas City Southern 69,787,071 1,816,759 785.89 Norfolk Southern 463,267,278 32,317,375 865.75 Union Pacific 1,185,146,529 143,470,336 974.64 Total 3,770,914,002 301,046,290 929.47 * Excluding Amtrak
** Includes work trains
*** CP’s line-haul fuel use values include 2008 dat a (rather than 2007) for their Delaware and Hudson subsidiary.3

Method

Earlier efforts to characterize line-haul railroad emissions relied on highly aggregated activity data and generally apportioned annual system-wide fuel use e qually across all route miles of track operated by a Class I railroad. However, the majority of freight tonnage carried by Class I railroads is concentrat ed on a disproportionately small number of route miles (Figure 1). In addition, emissions calculations were previously based on an estimate of annual nati onwide-average locomotive fleet mix to create one
set of emissions factors.

For this inventory, the Class I Railroads allowed E RTAC Rail access under a confidentiality agreement to a link-level (single lengths of track) line-haul GIS layer activity dataset managed by the Federal
Railroad Administration 9 . Each railroad also provided fleet mix informatio n that allowed ERTAC Rail to calculate weighted emission factors based on the fraction of their line-haul fleet meeting each Tie r level category. The use of this data, largely foll owing a line-haul inventory methodology recommended by Sierra Research 2, 3 , resulted in a link-level line-haul locomotive emi ssion inventory using railroad-specific emission factors. This seg ment-level inventory is nationwide, aggregated to state and county level files and can be converted t o gridded emissions files for use in photochemical and dispersion modeling. Link-level emissions may be provided to third parties for special study requests pending approval of any Class I railroads operating in the study domain. The calculations ar e described below as a two-part process, first calcul ating railroad-specific factors and then total emissions per rail link.

Figure 1. US Railroad Traffic Density in 2006. 10 MGT is million gross tons.4

1. Calculate Railroad-Specific Factors.

The EPA provides annual default Emission Factors fo r locomotives based on characteristic operating cycles (‘duty cycles’) and the estimated nationwide fleet mixes for both switcher and line-haul locomotives. However, fleet mixes vary from railro ad to railroad and, as can be seen in Figure 2, Cla ss I railroad activity is highly regionalized in natur e and subject to issues of local terrain such as operation on plains vs. mountainous areas, which ca n have a significant impact on fuel consumption
and emissions.

Figure 2. Class I Railroad Territories in the Unit ed States 11

.

As an alternative approach to using a single nation wide set of emission factors, ERTAC Rail requested each Class I company to provide a description of th eir line-haul fleet mix based on Tier rating, which each company provided under a confidentiality agree ment. An engine’s Tier level is based on the year the engine was built and determines allowable emiss ion limits (Table 3).

Table 3. EPA line-haul locomotive Emission Factors by Tier, 1997 standards (grams/gal). Note that the new standards released in 2008 did not app ly to fleets in the year 2008. 12

PM 10 HC NO
x CO Uncontrolled (pre-1973) 6.656 9.984 270.4 26.624 Tier 0 (1973-2001) 6.656 9.984 178.88 26.6245

Tier 1 (2002-2004) 6.656 9.776 139.36 26.624 Tier 2 (2005 + ) 3.744 5.408 102.96 26.624 Based on values in EPA Technical Highlights: Emiss ion Factors for Locomotives, EPA Office of Transportation and Air Quality, EPA-420-F-09-025, A pril 2009.

Weighted Emission Factors (EF) per pollutant for ea ch gallon of fuel used (gm/gal or lbs/gal) were
calculated for each Class I railroad fleet based on its fraction of line-haul locomotives at each regu lated Tier level (Eqn 1; Table 3).



# ∑

= = 4

1 )

* (

T TRR

iT iRR f EF EF Equation 1

EF

iRR = Weighted Emission Factor for pollutant i for Cl ass I railroad RR (gm/gal).

EF

iT = Emission Factor for pollutant i for locomotives in Tier T (gm/gal) (Table 3).
There were 4 Tiers of locomotives in the 2008 fleet s. f TRR = Fraction of railroad RR fleet in Tier T.

While engine emissions are variable within Tier cat egories, this approach likely provides better regional estimates than uniformly applying the nati onwide average emission factors. This approach likely provides conservative emission estimates as locomotive engines are certified to meet or exceed the emissions standard for each Tier, although emis sion levels may increase after certification and actual operations may vary widely from the line-hau l duty-cycle estimation.

Other emission factors are not engine specific. Fo r locomotives, PM 2.5 is assumed to be 97% of PM 10 12 , and emission factors applied for SO 2 and NH 3 are 1.88 g/gal 12 and 83.3 mg/gal 13 respectively. Greenhouse gases are estimated using emission facto rs shown in Table 4. Note that locomotive and marine engines are not subject to general non-road fuel or engine standards.

Table 4. EPA greenhouse gas emission factors for l ocomotive diesel fuel (grams/gal). 14

CO 2 N 2 O CH 4 Locomotive diesel 1.015E4 0.26 0.80

A Railroad Fuel Consumption Index (RFCI) was also c alculated for each Class I railroad using their system-wide line-haul fuel consumption (FC) and gro ss ton-mile (GTM) data reported in their annual R-1 reports submitted to the Surface Transportation Board 8 (Eqn 2). This value represents the average number of GTM produced per gallon of diesel fuel us ed over their system in a year, and varies between railroad carriers depending on factors such as fleet mix, system terrain, speeds, loading/weig ht of cargo, train type (e.g., intermodal, unit, and m anifest), and operating practices. (Table 2).

RR RR
RR FC GTM RFCI = Equation 26

RFCI RR = Railroad Fuel Consumption Index (gross ton-mile s/gal) per Class I railroad (RR).
GTM

RR = Gross Ton-Miles (GTM), annual system-wide gross ton miles of freight transported per RR. (R-1 Report Schedule 755, Li ne 104)
FC RR = Annual system-wide fuel consumption by line-haul and work trains per RR (gal)

(R-1 Report Schedule 750, Lines 1 and 6).

2. Calculate Emissions per Link.

Emissions of pollutant i per link L ( E iL ) are calculated by multiplying the gallons of dies el fuel consumed by each Class I railroad on the link by th at railroad’s weighted Emission Factor for the pollutant, and then summing emissions for all Class I railroads operating on that link (Eqn 3). This approach splits the activity on each link (represen ted by MGT) evenly between all railroads operating on the link. Note that the weighted Emission Facto rs are converted to tons/gal for these calculations

, and that variables with units in tons may represent tons of freight hauled (MGT, RFCI) or tons of pollutants (EF, E).



# ∑

= 

      

= N

RR iRR

RR L L

iL EF

RFCI l N MGT

E

1 6

*

* 10*

Equation 3

E iL = Emissions of pollutant i per link L (tons/year)

. N = Number of Class I railroads operating on link L.
MGT L = Millions of Gross Tons hauled per link per year from the FRA database (10 6 tons/yr) 9

. l L = Link length from the FRA database (miles).

EF

iRR = Weighted Emission Factor for pollutant i per rai lroad RR (Eqn 1; tons/gal).
RFCI

RR = Railroad Fuel Consumption Index per railroad RR (Eqn 2; gross ton-miles/gal).

Note that approximately 36% of Class I route miles in the United States are shared by more than one Class I carrier, a fraction that drops to 26% when neglecting track only shared between one Class I freight railroad and Amtrak. Accurately apportioni ng the specific fractions of tonnage (MGT) per carrier per link was considered, but after comparin g likely worst-case areas, the difficultly of mergi ng carrier-specific MGT with the aggregated FRA MGT da taset was considered too great considering the potential gain in accuracy. Where warranted, MGT d ata may be apportioned more accurately in the
future.

Limitations, Conclusions, and Future Work

Rail-related emissions can be important components of emissions inventories used to support effective air quality management practices at local, state, r egional, and national levels. Previous air quality studies often have not had the data needed to adequ ately represent this source sector. This line-haul inventory, as well as the companion Class I railyar d inventory and Class II/III inventory, greatly improve our ability to estimate of rail-related emi ssions. A systematic study of variability and uncertainty in line-haul locomotive emissions and a ctivity, by fleets, locations, and through time,7

would give additional valuable information for iden tifying how to best improve this inventory as well as provide an indication of how representative the inventory may be. An uncertainty study on the data used for this inventory, including the R-1 reported fuel use, the confidential link-level tonnage data

, and the duty-cycle estimate would also help in eval uating the quality of this inventory. Localized studies should examine how shared tracks are apport ioned between multiple carriers in their domain.

Early ERTAC Rail discussions concluded that link-le vel tonnage was the most important data to obtain, while other variables such as track grade a nd track speed could not be addressed at this time. ERTAC Rail calculated railroad-specific fleet-avera ged emission factors rather than applying the estimated national average; however, it is recogniz ed that emissions from individual engines are highl y variable even within Tier categories depending on v ariables such as the specific locomotive model, operation cycle, and conditions of operation. Futur e evaluation of emission variability within Tiers a nd between certain types of operation and locations wo uld be valuable.

Emissions inventory preparation guidance from the U .S. EPA describes locomotive activity as relatively constant throughout the year (e.g. no da ily, weekly, or seasonal variability); however, act ual activity levels do vary seasonally and annual avera ging may dilute or exaggerate concentrations during pollution episodes. ERTAC Rail and the Class I rai lroad community had some discussions addressing if incorporating more specific fleet mix or monthly or seasonal variation may be worthwhile, and these topics should be looked into further.

Finally, it is important to reiterate that the link -level MGT data maintained by the FRA is proprietar y and can only be released to agencies/groups outside the FRA with the express permission of each Class I railroad. It is possible that one or more Class I railroads could withhold permission for access, b ut data for specialized studies may be provided if req uested. This database can also be improved by better distinguishing between haulage and trackage rights, and by apportioning tonnage hauled on links to specific carriers.

We would like to thank the Class I Railroads and th eir representatives for their assistance and suppor t in the development of this inventory.

References

1. Eastern Research Group (ERG) for E.H. Pechan & Associates, Inc., “Documentation for Aircraft, Commercial Marine Vessel, Locomotive, and Other Nonroad Components of the National Emissions Inventory, Volume I – Methodolog y”; EPA Contract No.: 68-D-02-063. Prepared for the US EPA Emissions, Monitoring and A nalysis Division, Sept. 30, 2005. ftp://ftp.epa.gov/EmisInventory/2002finalnei/docume ntation/mobile/2002nei_mobile_nonroad_ methods.pdf . Related documents at ftp://ftp.epa.gov/EmisInventory/2002finalnei/docume ntation/mobile/2002nei_mobile_nonroad_ train.pdf

2. Sierra Research, Inc., “Revised Inventory Guidan ce For Locomotive Emissions”; Report No. SR2004-06-01. Prepared for Southeastern States Air Resource Managers (SESARM), June 2004. http://www.metro4-sesarm.org/pubs/railroad/F inalGuidance.pdf

3. Sierra Research, Inc., “Research Project: Devel opment of Railroad Emission Inventory Methodologies”; Report No. SR2004-06-02. Prepared f or Southeastern States Air Resource8

Managers (SESARM), June 2004. http://www.metro4- sesarm.org/pubs/railroad/FinalMethodologies.pdf

4. Environ, “Draft LADCO 2005 Locomotive Emissions”. P repared for Lake Michigan Air Director Consortium, Feb 2007. http://www.ladco.org/reports/technical_support_docu ment/references/ladco_2005_locomotive_ emissions.021406.pdf

5. Southern Research Institute, “NYSERDA Clean Diesel Technology: Non-Road Field Demonstration Program, Development of the 2002 Loco motive Survey for New York State”; Agreement Number 8958. Prepared for the New York St ate Energy Research And Development Authority (NYSERDA), Feb. 09, 2007. http://www.nyserda.org/publications/LocomotiveSurve yReportwithAppendices.pdf

6. American Short Line and Regional Association (ASLRR A) 2008 Fact Book. Available at www.alsrra.org

.
7. M. Bergin; M. Harrell; J. McDill; M. Janssen; L. Dr iver; R. Fronczak; R. Nath,; and D. Seep. "ERTAC Rail: A Collaborative Effort in Building a R ailroad-Related Emissions Inventory Between Eastern States Air Protection Agencies and Participation with the Railroad Industry," 18th Annual International Emission Inventory Confer ence. Baltimore, MD. April 14 - 17, 2009. Paper and presentation available at: http://www.epa.gov/ttn/chief/conference/ei18/sessio n6/bergin.pdf

8. Surface Transportation Board R-1 Reports, available at: http://www.stb.dot.gov/stb/industry/econ_reports.ht ml

. 9. Confidential database was provided with assistance from Raquel Wright of the Federal Railroad Administration. Similar public data provi ding ranges of tonnage hauled rather than link-level tonnage is available from the Bureau of Transportation Statistics in the NTAD 2009 shapefile data (data is representative for the year 2007): http://www.bts.gov/publications/national_transporta tion_atlas_database/2009

. 10. US DOT Bureau of Transportation Statistics’ 2008 Na tional Transportation Atlas Database.

11. Freight Railroads in the United States 2008. Assoc iation of American Railroads. Available at: http://www.aar.org/~/media/AAR/InCongress_Railroads States/2008unitedstates.ashx

.
12. EPA Technical Highlights: Emission Factors for Loc omotives, EPA Office of Transportation and Air Quality, EPA-420-F-09-025, April 2009. http://www.epa.gov/otaq/regs/nonroad/locomotv/420f0 9025.pdf

13. Estimating Ammonia Emissions From Anthropogenic Non agricultural Sources - Draft Final Report by E.H. Pechan & Assoc. April 2004. Prepare d for EPA/STAPPA-ALAPCO Emission Inventory Improvement Program. Supported by persona l communication (5/6/2010) with Craig Harvey, US EPA, OTAQ, and Robert Wooten, NC DENR. http://www.epa.gov/ttnchie1/eiip/techreport/volume0 3/eiip_areasourcesnh3.pdf

14. U.S. Environmental Protection Agency. Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990- 2005, EPA 430-R-07-002, Annex 3.2, (April 2007), we b site: http://www.epa.gov/climatechange/emissions/usinvent oryreport.html

.9

Appendix A: ERTAC Rail Data Workgroup

REPRESENTATIVE ORGANIZATION
Matt Harrell IL EPA Michelle Bergin (Co-Chair) and Byeong Kim GA EPD Mark Janssen (Co-Chair) LADCO
Julie McDill and Patrick Davis MARAMA Laurel Driver US EPA OAQPS
Robert Fronczak AAR
Steven Sullivan ASLRRA
Rick Nath CSX David Seep and Lyle Staley BNSF Ken Roberge CPR
Carl Akins and Peter Conlon KCS
Erika Akkerman CN
M. John Germer UP
Brent Mason and Richard Russell NS
Joanne Maxwell Amtrak

Appendix B: Source and Year of Data Utilized for E ach Inventory

Data Year Source

Class I Line-Haul

Annual Line-Haul Fuel Use
and Gross Ton-Miles 2007 STB R-1 Reports (CP data for D&H is for 2008.)

Line-haul fleet mix for
emission factors 2008 Each Class I railroad

Link-level tonnage 2007 FRA confidential database

Class I Railyards (Switcher Locomotives)

Annual Switcher Fuel Use 2008 R-1 Reports

Switcher fleet mix for
emission factors 2008 Each Class I railroad

Link-level tonnage or Density Code (for activity estimate) 2007 FRA confidential database

Class II and III Locomotives

Annual Total Fuel Use 2008 ASLRRA Annual Report (20 08)

Track length and railroad 2007 FRA confidential dat abase

Estimated fleet mix for
emission factors Discussions with ASLRRA and Class II and III representatives.