Fugitive Dust from Coal Trains:Factors Effecting Emissions& Estimating PM2.5Robert KotchenrutherEPA Region 10NW-AIRQUEST 2013BackgroundThe main reason I looked intothis topic was to address apublic comment EPA received inrelation to our federalregister notice, which proposed approving WA Dept. ofEcology’s 2008 baseline emissions inventory (EI) forTacoma.The comment came from the Sierra Club and suggestedthe Tacoma 2008 EI was deficient for not discussing oraccounting for fugitive dust fromcoal trains in the EI.I was asked to see what couldbe estimated about coaltrain fugitive dust impacts in Tacoma.BackgroundBased on US Coal export data*, coal exports from the‘Seattle’ export district (includes Tacoma up through theCanadian boarder) were as follows:So there was some level ofcoal transported in 2008 (andprobably through Tacoma).*http://www.eia.gov/coal/Year Coal Exported (tons)2008 305812009 3652602010 35002042011 48544512012 4746960Why is this an area of interest now generally?3⁄4There is growing interest from Asian markets in U.S. export coal.3⁄4Currently there are 7 proposed or existingcoal export terminals along the west coast(4 U.S. & 3 Canadian).3⁄4Coal transport could increase quickly.Existing and proposed coal export capacity.(in millions of tons)BC Canada201220172022Prince Rupert 0.0 1.5 5.0N. Vancouver 0.0 2.0 5.0Roberts Bank 5.0 8.0 15.0WashingtonCherry Point 0.0 27.5 52.5Grays Harbor 0.0 0.0 5.0Longview 0.0 27.5 48.0OregonSt. Helens0.05.021.0Boardman 0.0 3.5 8.5Coos Bay0.00.010.0Totals5.0 70.0 139.0(Source: Whiteside et al., 2012)Coal Transport and Source Location3⁄4The majority of export coal would come from the Powder River Basin (PRB) in MT/WY.3⁄4Based on current pricing, BNSF would be the primary U.S. rail carrier from PRB to PNW.Rail routes from PRB to proposed U.S. Pacific Northwest Coal TerminalsPowder River BasinCoal Train Frequency Based on Projected Capacity3⁄4The number of coal trains per day on rail routes would significantly increase if theseterminals are built.Proposed coal export capacity and number of projected loaded coal trains per day.BC Canada2022 (106tons)Loaded trains per day*Prince Rupert 5.0 0.9N. Vancouver 5.0 0.9Roberts Bank 15.0 2.8WashingtonCherry Point 52.5 9.8Grays Harbor 5.0 0.9Longview 48.0 8.9OregonSt. Helens21.03.9Boardman 8.5 1.6Coos Bay10.01.9Totals139.0 25.8(*assumes 14,750 tons per train, 125 cars per trains; there willbe an equal number of empty trains returning to the PRB)Some Communities will be Impacted More than Others3⁄4Some transit portions have multipleroute options, some only one.3⁄4EveryBNSF coal train from the PRB to PNW would go through ‘the funnel’(Sandpoint – Spokane)3⁄4Three BNSF routes from Spokane to pacific terminals (all would be utilized).BNSF – Pacific Northwest Rail Map‘The funnel’Sandpoint, ID – Spokane, WAThree Routes from Spokane to coastStevens PassStampede Pass *(empty returns only)Columbia River GorgeCommunity ConcernsThere are a range of community concerns related toincreased coal train traffic, some of these are:3⁄4Air quality impacts from fugitive coal dust& increased diesel emissions3⁄4Ecological impacts of coal dust3⁄4Derailments3⁄4Longer rail crossing wait times3⁄4Rail infrastructure improvementcost burden on local communities3⁄4‘Nuisance dusting ‘ of coal duston cars/homes3⁄4Rail congestion adverse impacts on current railcustomers (e.g., container ports, ag shipments)3⁄4Long term climate impactsFactors Effecting the Amount of Fugitive Coal Dust fromCoal Trains.Car and load geometryrail car dimensionscoal load profiletotal exposed surface area of coalCoal physical propertiescoal moisture contentcoal size distributionTrip specificstrain speeds throughout routeload jostling in routetotal journey lengthweather: wind, precipitation, tempDust controlscontrol measure effectiveness andpercent remaining at end of journeyDust control measuresRail lines have an economic incentive to reduce fugitive coaldust... coal dust in track ballast increases the frequency andcost of track maintenance and can lead to derailments.In 2010 BNSF and Union Pacific conducted a field evaluationof coal dust suppressant technologies.3⁄4Trackside and train-board aerosol monitors were used.3⁄41633 coal trains treated with various dust suppressanttechnologies.>85% dust suppression was achieved with:Specific load profile guidelinesandapplying a topper agent to loaded coalAs of October 2011 BNSF’s CoalLoading Rule requires coalshippers to use measures achieving > 85% dust suppression.Estimating Fugitive Coal Dust Emissions from Coal Trains.No clear information about how much coal islost through fugitive dust in transit.Various sources give a range of 0.5% to 3% of total coal transported is lost through fugitivedust when there are no dust control measures.Wind tunnel experiments (1983) have estimated losses on the order of 0.9 to 1.8% for a1100 km journey.Canadian EI ExampleCanadians EI’s have been using a distance based equation based on a report titled“A Study of Fugitive Coal Dust Emissionsin Canada” (Cope and Bhattacharyya, 2001).The base equation is (for total suspended particulate, TSP):Emissions Factor (kg/tonne) = 0.1*(0.62*D)0.6WhereD = total distance travelled by rail cars (km)This equation gives 0.5% coal loss over a 1100 kmtransit, so on the low end of the 0.5 – 3.0%uncontrolled coal fugitive dust losses.Their recommended equation for TSPestimates yearly emissions including terms forprecipitation (P), emissions controls (CE), and estimating emissions for only a segment (SD)of the total rail trip.Emissions Factor (kg/tonne) = 0.1*(0.62*D)0.6* (365-P)/365 * (SD/D) * (100-CE)/100WhereD = total distance travelled by rail cars (km)SD = rail segment estimation emissions for (km)P = number of days in the year with measureable precipitation (rain and snow)CE = Control efficiency of any applied dust control measures (%).Example: Applying Canadian Method to TacomaWRAP and AP-42 recommended a PM2.5 / TSP ratio of 0.15(Cope and Bhattacharyya used 0.2, from US EPA AP-42 c. 2000)PM2.5Emissions Factor = 0.15 * TSP Emissions Factor (kg/tonne)Example for Tacoma WA using Cope and Bhattacharyya (2001) formula.(Emissions Factor (kg/tonne) = 0.1*(0.62*D)0.6* (365-P)/365 * (SD/D) * (100-CE)/100)Assumptions: SD = 40 km, D = 2414 km (1500 mi), PM2.5/TSP EF = 0.15all Seattle export district coal exported through Tacomaall projected Cherry Point coal exported through TacomaTacoma nonattainment area estimated coal train fugitive PM2.5 (tons per year)For comparison, the Ecology Tacoma 2008 SIPEI lists yearly emissions of PM2.5 of:1199 TPY for Residential wood combustion&411 TPY for onroad sourcesYear Control Efficiency (%) # Precipitation days Coal Exported (tons)Tacoma NAA PM2.5 (TPY)2008 0 161 305810.32009 0 146 3652604.42010 0 190 350020433.52011 85 (3 months) 166 485445144.42012 85 177 47469607.32017* 85 168 2750000044.52022* 85 168 5250000084.9*projectedUncertainties with Canadian method:Many, but it doesgive us an estimation method.Questions / unknowns / simplifications•Some evidence for nonlinear dust loss over journey (more earlier on), but this equationassumes linear•Majority of dust lost may be through ‘dustingevents’. Some sections of track may bemore prone to dusting events based on topography, typical winds, typical train speed, etc.•Effectiveness of controls may wear off throughout journey, leading to more dust later inthe journey.•Does not account for emissions from ‘empty’ return trains (coal residue can emit fugitivedust)•Fugitive dust is directly related to train speed, train speeds make be slower throughcities(?)•How variable is the coal size distribution?•How variable is coal moisture content?•How important are seasonal effects (winter/summer – temperature / humidity / winds )•Effects of precipitation are simplified.However, for estimating annual emissions theimportance of some of the above variabilitymay be reduced.Other activity around coal train fugitive dust?For the Gateway Pacific Terminal at Cherry Point WAAn environmental impact statement (EIS) isbeing developed under guidelines from theNational Environmental Policy Act (NEPA) and the State Environmental Policy Act (SEPA).Air quality is one of many environmental impacts under review.Uncertain if this will lead to measurements and/or improved fugitive dust estimates.The agencies coordinating the EIS areU.S. Army Corps of Engineers,WA State Department of Ecology, andWhatcom CountyEIS Timeline:9/2012 – 1/2013 Public input on scope of EIS3/2013 EIS scoping summary report issued (summary of comments)~2014 Issue draft EIS~2014/2015 Issue final EISOther activity around coal train fugitive dust?Dan Jaffe (UW Prof.) will conduct a short trackside study based on ‘crowdsource’ funding.Duration: 4-6 weeksLocation: North of Seattle (?)Time: Summer/Fall 2013Currently proposing tomeasurePM1,PM2.5,PM10,TSP, andMet. variablesSelected References:BNSF, 2010, Summary of BNSF/UP Super Trial 2010,http://www.bnsf.com/customers/pdf/coal-super-trial.pdfCope and Bhattacharyya, 2001, A Study of Fugitive Coal Dust Emissions in Canada, AnUnpublished Report Prepared for the CanadianCouncil of Ministers of the Environment.Cowherd, 2006, Background Document for Revisions to Fine Fraction Ratios Used for AP42 Fugitive Dust Emission Factors,http://www.epa.gov/ttn/chief/ap42/ch13/bgdocs/b13s02.pdfUS EPA, 2013, AP-42 Emissions Factors,http://www.epa.gov/ttnchie1/ap42/Whiteside et al., 2012, Heavy Traffic Ahead:Rail Impacts of Powder River Basin Coal toAsia by Way of Pacific Northwest Terminals,http://heavytrafficahead.org/pdf/HeavyTraffic-Ahead-web.pdfThank you foryour attention!