Air Transport Calculators for PEF

Particulate Emission Factor Wind Driven
PEF Equation
Albuquerque, NM (3) Atlanta, GA (6) Bismarck, ND (5) Boise, ID (4) Casper, WY (4) Charleston, SC (6) Chicago, IL (7) Cleveland, OH (7) Denver, CO (4) Fresno, CA (2) Harrisburg, PA (7) Hartford, CT (8) Houston, TX (6) Huntington, WV (7) Las Vegas, NV (3) Lincoln, NE (5) Little Rock, AR (6) Los Angeles, CA (2) Miami, FL (9) Minneapolis, MN (5) Philadelphia, PA (8) Phoenix, AZ (3) Portland, ME (8) Raleigh, NC (6) Salem, OR (1) Salt Lake City, UT (4) San Francisco, CA (2) Seattle, WA (1) Winnemucca, NV (4) Default   City (Climatic Zone) - Selection based on most likely climatic conditions for the site As (acres) Um (mean annual wind speed) m/s	Ut (equivalent threshold value) V (fraction of vegetative cover) unitless
A (PEF Dispersion Constant) B (PEF Dispersion Constant) C (PEF Dispersion Constant)	F(x) (function dependent on Um/Ut) unitless PEF (particulate emission factor) m3/kg Q/Cwind (inverse of the ratio of the geometric mean air concentration to the emission flux at the center of a square source) g/m2-s per kg/m3
NOTES: The Q/Cwind equation and the dispersion constants A, B and C were taken from Exhibit D-2 of the Supplemental Soil Screening Guidance. A, B, C = PEF region-specific dispersion constants (unitless) F(x) values for each city are taken from the Soil Screening Guidance Technical Background Document Appendix D Table 2.

Time Spent on Site
DWcw (days worked - construction worker) day/wk EWcw (weeks worked - construction worker) wk/yr FD Unitless Dispersion Correction Factor EDcw (exposure duration - construction worker) yr	EFcw (exposure frequency - construction worker) day/yr ETcw (exposure time - construction worker) hr tc (overall duration of construction) hours Tt (overall duration of traffic) s
NOTES: tc = ED * EW * 7 days/week * 24 hours/day Tt = ED * EF * ET * 3600 s/hour FD = 0.1852 + (5.3537/tc) + (-9.6318/tc2)

Subchronic Particulate Emission Factor Mechanically Driven - Unpaved Road Traffic
PEFsc Equation
WR (width of road segment) ft Mdry (road surface material moisture content under dry, uncontrolled conditions) % number of cars number of trucks tons/car	tons/truck p (days per year with at least .01" of precipitation) days/year s (road surface silt content) % As (acres)
LR (length of road segment) ft A (Dispersion Constant) AR (surface area of contaminated road segment) m2 B (Dispersion Constant) C (Dispersion Constant) total number of vehicles	ΣVKT (sum of fleet vehicle km traveled) km W (mean vehicle weight) tons distance (road length) km/day PEFsc (subchronic particulate emission factor) m3/kg Q/Csr (inverse of the ratio of the geometric mean air concentration to the emission flux along a straight road segment bisecting a square site) g/m2-s per kg/m3
NOTES: Contact your regional risk assessor for assistance. When calculating ΣVKT, distance (road length) is calculated by assuming the contaminated area of surface soil (As) is a square and that the road divides the square evenly. For example, if As is 0.5 acres (Asurf = 2,024 m2), the road length would be the square root of 2,024, or .045 km. The Q/Csr equation and dispersion constants A, B and C were taken from Equation E-19 of the Supplemental Soil Screening Guidance. The PEF equation is Equation E-18 in the Supplemental Soil Screening Guidance.

Subchronic Particulate Emission Factor - Other Construction Activities
PEF`sc Equation
Ac (acres) Ac-doz (areal extent of dozing) acres Aexcav (area of excavation site) m2 Ac-grade (areal extent of grading) acres Ac-till (areal extent of tilling) acres Bl-doz (dozing blade length) m Bl-grade (grading blade length) m Mm-doz (Gravimetric soil moisture content) % Mm-excav (Gravimetric soil moisture content) % NA-dump (number of times soil is dumped) NA-till (number of times soil is tilled)	NA-doz (number of times site was dozed) NA-grade (number of times site was graded) Sdoz (dozing speed) kph Sgrade (grading speed) kph dexcav (average depth of excavation site) m ρsoil (In situ soil density) Mg/cm3 - chemical-specific sdoz (soil silt content) % still (soil silt content) % Um (mean annual wind speed) m/s Ut (equivalent threshold value) m/s V (fraction of vegetative cover)
A (Dispersion Constant) Asurf (areal extent of site) m2 B (Dispersion Constant) C (Dispersion Constant) J`T (g/m2s) Mdoz (dust emitted from dozing operations) g Mexcav (dust emitted from excavation soil dumping) g Mgrade (dust emitted from grading operations) g	Mtill (dust emitted from tilling operations) g Mwind (dust emitted by wind erosion) g ΣVKTdoz (sum of fleet vehicle km traveled) km ΣVKTgrade (sum of fleet vehicle km traveled) km F(x) (function dependant on Um/Ut derived using Cowherd et al. (1985)) PEF`sc (subchronic particulate emission factor) m3/kg Q/Csa (inverse of the ratio of the geometric mean air concentration to the emission flux at the center of a square source) g/m2-s per kg/m3
NOTES: Contact your regional risk assessor for assistance. The Q/Csa equation and the dispersion constants A, B and C were taken from Equation E-15 of the Supplemental Soil Screening Guidance. The PEF equation is from Equation E-26 in the Supplemental Soil Screening Guidance.

Mechanical Particulate Emission Factor for Off-site Receptors (Standard Vehicle Traffic)
PEFoff
number of cars number of trucks tons/car tons/truck Albuquerque, NM (3) Atlanta, GA (6) Bismarck, ND (5) Boise, ID (4) Casper, WY (4) Charleston, SC (6) Chicago, IL (7) Cleveland, OH (7) Denver, CO (4) Fresno, CA (2) Harrisburg, PA (7) Hartford, CT (8) Houston, TX (6) Huntington, WV (7) Las Vegas, NV (3) Lincoln, NE (5) Little Rock, AR (6) Los Angeles, CA (2) Miami, FL (9) Minneapolis, MN (5) Philadelphia, PA (8) Phoenix, AZ (3) Portland, ME (8) Raleigh, NC (6) Salem, OR (1) Salt Lake City, UT (4) San Francisco, CA (2) Seattle, WA (1) Winnemucca, NV (4) Default   City (Climatic Zone) - Selection based on most likely climatic conditions for the site	p (days per year with at least .01" of precipitation) days/year As (acres) Um (mean annual wind speed) m/s Ut (equivalent threshold value) V (fraction of vegetative cover) unitless
A (PEF Dispersion Constant) Asurf (areal extent of site) m2 B (PEF Dispersion Constant) C (PEF Dispersion Constant) JT (g/m2s) Mroad (dust emitted by road traffic) g Mwind (dust emitted by wind erosion) g	total number of vehicles ΣVKT (sum of fleet vehicle km traveled) km W (mean vehicle weight) tons distance (road length) km/day F(x) (function dependant on Um/Ut) unitless PEFoff (particulate emission factor) m3/kg Q/Coff (inverse of the ratio of the geometric mean air concentration to the emission flux at the center of a square source) g/m2-s per kg/m3
NOTES: The Q/Coff equation and the dispersion constants A, B and C were taken from Exhibit E-5 of the Supplemental Soil Screening Guidance. The PEF equation is from Equation E-29 in the Supplemental Soil Screening Guidance.

Mechanical Particulate Emission Factor for Off-site Receptors (Other Construction Activities)
PEF`off
Ac (acres) Ac-doz (areal extent of dozing) acres Aexcav (area of excavation site) m2 Ac-grade (areal extent of grading) acres Ac-till (areal extent of tilling) acres Bl-doz (dozing blade length) m Bl-grade (grading blade length) m Mm-doz (Gravimetric soil moisture content) % Mm-excav (Gravimetric soil moisture content) % NA-dump (number of times soil is dumped) NA-till (number of times soil is tilled)	NA-doz (number of times site was dozed) NA-grade (number of times site was graded) Sdoz (dozing speed) kph Sgrade (grading speed) kph dexcav (average depth of excavation site) m ρsoil (In situ soil density) g/cm3 - chemical-specific sdoz (soil silt content) % still (soil silt content) % Um (mean annual wind speed) m/s Ut (equivalent threshold value) m/s V (fraction of vegetative cover)
A (PEF Dispersion Constant) Asurf (areal extent of site) m2 B (PEF Dispersion Constant) C (PEF Dispersion Constant) J`T (g/m2s) Mdoz (dust emitted from dozing operations) g Mexcav (dust emitted from excavation soil dumping) g Mgrade (dust emitted from grading operations) g	Mtill (dust emitted from tilling operations) g Mwind (dust emitted by wind erosion) g ΣVKTdoz (sum of fleet vehicle km traveled) km ΣVKTgrade (sum of fleet vehicle km traveled) km F(x) (function dependant on Um/Ut derived using Cowherd et al. (1985)) PEF`off (particulate emission factor) m3/kg Q/Coff (inverse of the ratio of the geometric mean air concentration to the emission flux at the center of a square source) g/m2-s per kg/m3
NOTES: The Q/Coff equation is from Equation E-29 and the dispersion constants A, B and C were taken from Exhibit E-5 of the Supplemental Soil Screening Guidance. The PEF equation is from Equation E-25 in the Supplemental Soil Screening Guidance.