Summary
SECTION 7.10
UNPAVED ROAD DUST — NON-FARM ROADS
(This page last updated
on October 22, 2014)
Emission
Inventory Source Category
Miscellaneous
Processes / Road Dust / Unpaved Road Travel Dust
| Emission Inventory Code (EIC) | CES Codes | Description |
| 645-638-5400-0000 | 47399 | City & County Roads |
| 645-640-5400-0000 | 47407 | U.S. Forest and Park Roads |
| 645-644-5400-0000 | 47423 | BLM & BIA Roads |
| 645-648-5400-0000 | 82156 | Unspecified Unpaved Roads |
Method
Summary: This
category includes 2008 estimates of fugitive dust particulate matter entrained
by vehicular travel on unpaved roads. Road dust emissions are estimated for
city and county roads, U.S. Forest and Park roads, BLM and BIA roads, and
unspecified unpaved roads.
Activity
Data Source: County
specific estimates of unpaved road mileage are based on 2008 data from
the California Statewide Local Streets and Roads Needs Assessment, the
California Department of Transportation (Caltrans), counties and
air districts. Each mile of unpaved road
was assumed to receive ten vehicle passes per day and emissions were assumed to
be suppressed for each day with rainfall of 0.01 inch or greater. Rainfall data
were obtained from the Western Regional Climate Center.
Emission
Factor Source: The
emission factor, 2.0 lbs PM10 per vehicle mile traveled (VMT), is computed by averaging unpaved road dust emission measurements performed
at different sites in the San Joaquin Valley by the University of California,
Davis and the Desert Research Institute. This emission
factor is used for both agricultural and non-agricultural unpaved roads.
Temporal
Data: Activity on unpaved roads is assumed to occur
primarily during daylight hours and to be uniform each day of the week. Monthly activity for each county/air basin/district
is adjusted to reflect rainfall, with decreased emissions allocated to the
rainy winter months.
Changes
in Method and Emissions Estimate: The emission factor was reduced by 15%, from 2.27 lbs PM10/VMT to 2.00 lbs PM10/VMT. The emission factor equation uses a revised particle size profile and incorporates a rainfall adjustment.
Activity data and temporal profiles were updated.
Growth
Parameter: Zero
growth is assumed for unpaved non-farm roads.
Statewide
Emissions Summary
(2008 — Annual Average Tons/Day, Uncontrolled)
|
EIC Code | TOG |
CO |
NOX |
SOX |
PM |
| 645-638-5400-0000 | 0.00 | 0.00 | 0.00 | 0.00 | 154.78 |
| 645-640-5400-0000 | 0.00 | 0.00 | 0.00 | 0.00 | 141.25 |
| 645-644-5400-0000 | 0.00 | 0.00 | 0.00 | 0.00 | 10.51 |
| 645-648-5400-0000 | 0.00 | 0.00 | 0.00 | 0.00 | 88.82 |
| Total | 0.00 | 0.00 | 0.00 | 0.00 | 395.36 |
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