WESTAR 2003 Fall Technical Conference Introduction to Class I Area Impact Analyses September 16, 2003 John Bunyak National Park Service

FLMs’ PSD permit review includes: Increment/Air Quality Analyses Best Available Control Technology (BACT) Analysis Air Quality Related Values (AQRV) Analysis

EPA CLASS I SIGNIFICANT LEVELS Federal Reg. July 23, 1996 SO2 3-hr = 1.0 ug/m 3, 24-hr = 0.2 ug/m 3, Annual = 0.1 ug/m 3 PM10 24-hr = 0.3 ug/m 3, Annual = 0.2 ug/m 3 NO2 Annual = 0.1 ug/m 3 EXCEEDING THESE VALUES TRIGGERS A CUMULATIVE INCREMENT ANALYSIS OR ANY IMPACT IS SIGNIFICANT AND TRIGGERS A CUMULATIVE INCREMENT ANALYSIS

EMISSION RATES & SOURCES New Source(s)- usually same emissions for new facility as Class II analysis Cumulative Class I increment analysis for pollutant & averaging time > EPA Class I SIL –All major/large sources up to 300 km from Class I area –Minor sources < 50km from Class I area- not same minor source inventory as Class II –Emissions=State’s permit limit for averaging time--usually short term limits

CALMET METEOROLOGICAL DATA How many years (1yr vs. 3yrs vs. 5yrs) –1 year is no longer allowed –3 years with MM data is acceptable –5 years of NWS data is acceptable CALMET/MM prognostic data (MM4-1990, MM5-1992, MM5-1996) x80 km MM4 data from NCDC x80 km MM5 data from NPS/FWS in MM4 format x36 km MM5 data with MM5 parameters; available from contractor New Extractor by NPS fixes problem with 1990 MM4 CALMET settings must stay fixed for the different years CALMET GRID CELLS 2km to 4km in size

CALPUFF Guidance in IWAQM 2 & FLAG Receptor Grid- NPS fixed receptors for its Class I areas CALPUFF settings must stay fixed for the different years For short term increments and visible haze, need to model short term State emission limits. Pounds per hour Pounds per MMBtu Annual increments and acid deposition can use annual TPY emission limits

EMISSIONS -VISIBILITY New Sources emit: SO2, SO4, NOx, EC, PMC, PMF, SOA Visibility impacts from: SO4, NO3, EC, PMC, PMF, SOA Cumulative Visibility Analyses –Recommended in FLAG –Same sources & distances as increment cumulative + their emissions of visibility impacting pollutants –i.e., if cumulative SO2 increment analysis; then need SO4, NOx, PM, etc. from all sources

VISIBILITY ISSUES H 2 SO 4 (sulfuric acid mist) forms (NH 4 ) 2 SO 4 which contributes visibility impairment so H 2 SO 4 needs to be explicitly modeled from: Coal fired power plants Oil fired turbines, engines, boilers Natural gas fired turbines, engines, boilers See NPS web site for speciation of PM emissions from gas fired turbines

ACID DEPOSITION SULFUR, NITROGEN TOTAL DEPOSITION = DRY + WET Report total deposition in the form of total S and N (include the N in (NH 4 ) for (NH 4 ) 2 SO 4 and (NH 4 )NO 3 Thresholds: EAST = S or N = 0.01 (Kg/ha/Yr) Thresholds: WEST = S or N = (Kg/ha/Yr) Analysis techniques not defined in FLAG Add new source’s impact to monitored values, no cumulative source analysis required Need to post process using Postutil to combine N species and S species

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