Environmental Impact Statement - Sonoma Land Trust

California Department of Fish and Game
U.S. Fish and Wildlife Service
Section 3.12. Noise
1 30-60 Minutes 50 45
2 15-30 " 55 50
3 5-15 " 60 55
4 1-5 " 65 60
5 0-1 " 70 65
Policy NE-1a states that “Designate areas within Sonoma County as noise
impacted if they are exposed to existing or project noise levels exceeding 60 dB
LdN, 60 dB CNEL, or the performance standards in Table NE-2 above.”
With regard to transportation noise from sources such as traffic, railroads, and
airports the Sonoma County General Plan stipulates that exterior noise must be
reduced to levels of “60 dB L dn or less in outdoor activity areas.” Outdoor
activity areas typically include backyards, parks, and outdoor play areas. A
maximum level of up to 65 dB L dn may be allowed.
Environmental Consequences and Mitigation
Measures
Approach and Methods
Noise from construction activities has been evaluated using methods
recommended by the Federal Highway Administration (FHWA) (Federal
Highway Administration 2006). Noise from the post-construction operation of
new storm water pumps has been evaluated using methods recommended by
Hoover and Keith (Hoover and Keith 1996). Since Sonoma County does not have
a noise ordinance and does not explicitly limit construction activities (e.g., hours
of operation, maximum allowable noise levels), noise impacts were evaluated by
comparing predicted noise levels to significance thresholds that are based
primarily on local noise standards.
Impact Mechanisms
Construction
Construction activities associated with restoration could intermittently generate
elevated noise levels on and adjacent to the Project site.
Construction activities associated with the restoration would include demolition,
grading and earthmoving activities, hauling materials, building structures, and
Sears Point Wetland and Watershed Restoration
Project Final Environmental Impact
Report/Environmental Impact Statement
3.12-5
April 2012