Environmental Impact Statement - Sonoma Land Trust

California Department of Fish and Game
U.S. Fish and Wildlife Service
Section 3.11. Air Quality
8-hour standard is 9.0 ppm, not be exceeded, and the federal 8-hour standard is 9
ppm, not to be exceeded more than 1 day per year. State and federal standards are
summarized in Table 3.11-1.
Inhalable Particulates
Health concerns associated with suspended particulate matter focus on those
particles small enough to reach the lungs when inhaled. Particulates can damage
human health and retard plant growth. Particulates also reduce visibility, soil
buildings and other materials, and corrode materials. The primary particulate of
concern in the project area is PM10.
PM10 emissions are generated by a wide variety of sources, including
agricultural activities, industrial emissions, dust suspended by vehicle traffic, and
secondary aerosols formed by reactions in the atmosphere.
Particulate matter concentrations in the Bay Area and southern North Coast Air
Basin have shown no strong overall trends over the last ten years. While many
stationary sources of particulate matter such as factories and mills have either
closed or been controlled, area sources such as vehicle traffic and residential
wood-burning have been increasing, off-setting the reductions in the stationary
emissions (Nichols-Berman 2006).
The federal and state ambient air quality standard for particulate matter applies to
two classes of particulates: PM10 and PM2.5. The state PM10 standards are 50
micrograms per cubic meter (µg/m 3 ) as a 24 hour average and 20 µg/m 3 as an
annual arithmetic mean. The federal PM10 standard is 150 µg/m 3 as a 24-hour
average. The federal PM2.5 standards are 15 µg/m 3 for the annual average and 35
µg/m- for the 24-hour average. The state PM2.5 standard is 12 µg/m 3 as an
annual arithmetic mean. State and federal standards are summarized in Table
3.11-1.
Toxic Air Contaminants
Toxic air contaminants (TACs) are another group of pollutants of concern.
Unlike criteria pollutants, no safe levels of exposure to TACs can be established.
There are many different types of TACs, with varying degrees of toxicity.
Sources of TACs include industrial processes (e.g., petroleum refining and
chrome plating operations), commercial operations (e.g., gasoline stations and
dry cleaners), and motor vehicle exhaust. Public exposure to TACs can result
from emissions from normal operations, as well as accidental releases of
hazardous materials during upset conditions. The health effects of TACs include
cancer, birth defects, neurological damage, and death.
In 1998, the Air Resources Board identified particulate matter from diesel-fueled
engines as a TAC. The state of California has begun a program of identifying and
reducing risks associated with particulate matter emissions from diesel-fueled
Sears Point Wetland and Watershed Restoration
Project Final Environmental Impact
Report/Environmental Impact Statement
3.11-4
April 2012