VISTAS BART Update

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VISTAS BART Update
Getting Our Hands around BART
VISTAS Technical and Planning Workgroups
Meeting September 7, 2006
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VISTAS BART Deliverables by Sep 06

• Final BART Modeling Protocol Dec 22, 2005
• Revision 1 Jan 2006, Rev 2 Mar 2006, Rev 3
  July 2006
• 2. CALPUFF demonstration for 3 sources Dec
  2005
• CALMET 12-km grid for VISTAS eastern US domain
  for 2001, 2002, and 2003 Jan 2006
• VISTAS states Advanced CALPUFF training Jan/Feb
  2006
• VISTAS version of CALPUFF model available by
  website http//www.vistas-sesarm.org/BART/calpuff.
  asp Apr 2006
• Instructions and example application of CALPUFF,
  CALPOST, POSTUTIL
• Supporting data files
• - ozone files
• - surface meteorology

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VISTAS BART Deliverables Sep 06

• CALMET 4-km subdomains for 2001, 2002, 2003
  Mar/Apr 2006
• Supporting data to allow development of finer
  grids
• Ammonia limiting method (ALM) in POSTUTIL using
  hourly background SO4, NO3, and NH4 from CMAQ to
  partition NH3 between SO4 and NO3
• Demonstration using 2002 CMAQ data in ALM
  reproduces 2002 IMPROVE monitoring data Jan
  2006
• b) Using 2002 CMAQ data (monthly average) in
  ALM reproduces 2001 and 2003 IMPROVE data
  Mar/Apr 2006
• EPA determined ALM is non-regulatory application
  of CALPUFF and not acceptable for BART
  application May 2006
• States request EPA Modeling Clearinghouse review
  July 2006

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VISTAS BART Deliverables Sep 06

• CALPUFF initial 12-km exemption runs for sources
  with Q/d for SO2 lt 10 Mar - Sep 06
• Received data for 63 sources for 10 states, less
  than 5 remaining
• For less than 5 sources within 50 km of Class I
  area, provided 4-km exemption runs
• Reporting underway
• Deliver source specific reports to the States
• Deliver summary report to VISTAS
• Evaluate relationship between emissions (Q)
  divided by distance (d) to maximum visibilty
  impact (dv)

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Q/D Plot Q SO2

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Q/D Plot Q NOx

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Q/D Plot Q PM10

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Q/D Plot Q SO2NOx

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Q/D Plot Q SO2NOxPM10

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Revisions to VISTAS BART Protocol

• Revision 1 Jan 06
• 98th percentile calculated for Class I area, not
  a specific receptor in Class I area
• Revision 2 Mar 06
• ALM method not available for use in initial
  exemption modeling follow FLAG guidance
• Change recommendation to use Pasquill-Gifford
  dispersion coefficient rather than
  turbulence-based dispersion coefficient per EPA
  Region 4
• Revision 3 Jul 06
• Reflect change in contract from Earth Tech to TRC
  
• Either annual average or 20 best days acceptable
  to represent natural conditions, to be decided by
  state, per EPA settlement

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Revisions to VISTAS BART Protocol

• Revision 3 Jul 06 (continued)
• Report state decision from sensitivity analyses
  that evaluated if PM, VOC, and NH3 are
  visibility-impairing pollutants and should be
  included in BART modeling
• PM included, VOC not included, NH3 included for
  few sources gt 250 tons NH3
• Ivar Tombach with Jim Boylan drafting report
  documenting sensitivity results to support states
  decision
• Resolve that POSTUTIL with Ammonia Limiting
  Method can be used to repartition NO3 for
  fine-grid (4 km or less) CALPUFF modeling
• Constant NH3 value to be used per FLAG guidance
• CMAQ background values for SO4, NO3, NH4 not to
  be used, per EPA
• ALM not to be used for 12-km initial BART
  exemption modeling

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Revisions to VISTAS BART Protocol

• Yet to Come Use of new IMPROVE equation
• IMPROVE workgroup defined method to apply new
  IMPROVE equation to natural background conditions
• EPA Q A (Aug 3, 2006) page 14 states that
  either new or original equation may be used and
  recommends consistency in application for BART
  and reasonable progress
• VISTAS intends to use both new and original
  IMPROVE equation to demonstrate reasonable
  progress at Class I areas
• States have discretion to allow sources to use
  new IMPROVE equation, in addition to original
  equation, for BART.
• Ivar Tombach developed post processor tool to use
  to recalculate dv impact using CALPOST outputs
  and new equation. FLM and EPA are reviewing tool.
  

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Documents Provided on CALPUFF Website

• VISTAS version of CALPUFF model
• Instructions to apply CALPUFF
• Sample Data Files
• Map of CALPUFF domains
• CALMET Ready Meteorological Files
• States distribute 12 km or 4 km CALMET grids
• Speciation Profiles
• SMOKE, NPS

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Documents Provided on VISTAS Website

• VISTAS BART Modeling Protocol version 3.2
• VISTAS BART Modeling Protocol Revision 3.2 Log
• Link to Class I receptor grid

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Key Policy Decisions

• EGU do not have to evaluate SO2 and NOx emissions
  because CAIR BART, per EPA settlement.
• EGU do have to consider PM emissions
• States can include PM in model plant analysis
• Model plant analysis set limits for SO2 plus NOx.
  
• Need to account for differences in light
  extinction between PM components and SO4 and NO3.
• Source can take emissions limit to exempt from
  BART, controls and permit have to be in place by
  SIP submittal
• Reduce emissions below 250 ton threshold
• Reduce emissions to meet model plant criteria
• Reduce emissions below threshold impact (0.5 DV)

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Key Policy Decisions

• VOC not modeled as visibility impairing
  pollutant, NH3 only modeled for sources gt 250
  tons NH3
• Clarify definition of integral to process?
• Clarify source of data to speciate PM (NPS vs AP
  42 vs Joe)?
• Clarify can use more recent emissions data if
  recent controls installed? What say about max 24
  hr?
• What else?