treasure valley road dust study: final report - ResearchGate

as well as the effects of application of traction control substances, street sweeping, and
precipitation on PM 10 emissions from roads over the Treasure Valley. Third, TRAKER data were
the basis for assembling year 2000 and future year PM 10 and PM 2.5 emissions inventories for
road dust.
1.3.2 Laboratory Analysis
Road soil samples collected in the field were sent to DRI’s Environmental Analysis
Facility in Reno, NV for analysis. Samples were sieved and weighed to determine the silt
content of the road soil. The silt contents were then used to calculate the silt loading on each of
the road sampled. Select silt samples were also resuspended in a specialized chamber to collect
only the PM 10 and PM 2.5 fraction of the material on filter substrates. These filters were
chemically analyzed to produce source profiles for future use in CMB receptor modeling.
1.3.3 Data Processing
TRAKER collects data from 10 separate onboard instruments every second of operation.
These data are synchronized with each other and are quality assured using validation criteria to
produce an unbiased measure of the PM 10 suspended from the road surface at a particular instant.
In coordination with a concurrent study of unpaved road dust emission (Gillies, 2000), the
TRAKER measurement was calibrated with horizontal particle flux measurements. The product
of the calibration study enabled the estimation of a road dust emissions potential for all roads
surveyed by TRAKER in the Treasure Valley.
The planning association for southwest Idaho (COMPASS) maintains a traffic demand
and forecasting model for Ada and Canyon counties. Road dust emissions inventories for the
Treasure Valley were prepared by integrating the measured TRAKER emissions potentials with
the traffic activity data from the COMPASS traffic demand model. Separate inventories were
calculated for wintertime and annual emissions for base and future years.
1.4 Guide to the Report
In this Section, we have stated the background, objectives, and technical approach of the
Treasure Valley Road Dust study. In Section 2, the silt sampling and analysis is presented along
with the results of the measurements. Section 3 discusses the principles of the TRAKER
operation, quality assurance tests, and TRAKER’s calibration with upwind-downwind emissions
fluxes. The TRAKER measurements in the Treasure Valley including data processing, street
surveys, loops, and the effects of street sanding and sweeping are discussed in Section 4. Section
5 documents the preparation of the emissions inventories from the TRAKER data and the silt
loading measurements. A preliminary modeling study aimed at esti mating the diminishment of
PM 10 dust fluxes with downwind distance from the source is presented in Section 6. Section 7
summarizes the chemical source profile data measured from the resuspended road soil samples.
Summary, conclusions, and recommendationsare contained in Section 8. A list of references
used throughout this report is given in Section 9. Details of silt loading sites and results,
historical meteorological characteristics of the Treasure Valley, and a guide to the electronic
format link-level emissions inventories are provided in the appendices to this report.
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