IDENTIFICATION OF AN ACCURATE SOIL SUSPENSION DISPERSION MODELING METHOD FOR USE IN ESTIMATING HEALTH-BASED SOIL CLEANUP LEVELS OF HEXAVALENT CHROMIUM IN CHROMITE ORE PROCESSING RESIDUES/
Pk. Scott et al., IDENTIFICATION OF AN ACCURATE SOIL SUSPENSION DISPERSION MODELING METHOD FOR USE IN ESTIMATING HEALTH-BASED SOIL CLEANUP LEVELS OF HEXAVALENT CHROMIUM IN CHROMITE ORE PROCESSING RESIDUES/, Journal of the Air & Waste Management Association [1995], 47(7), 1997, pp. 753-765
The primary health concern associated with chromite ore processing res
idues (COPR) at sites in Hudson County, NJ, is the inhalation of Cr(VI
) suspended from surface soils. Since health-based soil standards for
Cr(VI) will be derived using the inhalation pathway, soil suspension m
odeling will be necessary to estimate site-specific, health-based soil
cleanup levels (HBSCLs). The purpose of this study was to identify th
e most appropriate particulate emission and air dispersion models for
estimating soil suspension at these sites based on their theoretical u
nderpinnings, scientific acceptability, and past performance. The iden
tified modeling approach, the AP-42 particulate emission model and the
fugitive dust model (FDM), was used to calculate concentrations of ai
rborne Cr(VI) and TSP at two COPR sites. These estimated concentration
s were then compared to concentrations measured at each site, The TSP
concentrations calculated using the AP-42/FDM soil suspension modeling
approach were all within a factor of 3 of the measured concentrations
. The majority of the estimated air concentrations were greater than t
he measured, indicating that the AP-42/FDM approach tends to overestim
ate on-site concentrations. The site-specific Cr(VI) HBSCLs for these
two sites calculated using this conservative soil suspension modeling
approach ranged from 190 to 420 mg/kg.