Draft Environmental Impact Report - California Off Highway Vehicle ...

3.3 Noise
Noise Survey
In Clay Pit SVRA, the primary noise sources include vehicle traffic, aircraft overflights from the
nearby Oroville Municipal Airport, and shooting range activities at the nearby shooting range.
Ambient noise levels in the area are influenced by traffic on major roads such as Larkin Road and
SR 162.
A community noise survey was conducted on April 24, 2010, to document the existing noise
environment at noise‐sensitive receptors within the project area and existing noise sources.
Noise‐sensitive receptors in the project area were defined as residential land uses. The closest
noise‐sensitive receptor is a residence located to the west of Clay Pit SVRA between Larkin Road
and the Oroville Municipal Airport runway (Figure 3.3‐2). The dominant noise source identified
during the ambient noise survey was traffic from Larkin Road. However, the OHV recreationists at
Clay Pit SVRA, aircraft overflights, and shooting range activities also influenced ambient noise
levels in the project area. Measurements of noise levels were taken in accordance with American
National Standards Institute (ANSI) standards at three locations using a Larson Davis Laboratories
(LDL) Model 820 precision integrating sound‐level meter. The sound‐level meters were calibrated
before and after use with an LDL Model CAL200 acoustical calibrator to ensure that the
measurements would be accurate. The equipment used meets all pertinent specifications of the
ANSI for Type 1 sound‐level meters (ANSI S1.4‐1983[R2006]).
The locations for the community noise survey are shown in Figure 3.3‐2. The Leq, Lmax, L10, L50, and
L90 values were taken at each location, where the ambient noise was measured in hour‐long
intervals (Table 3.3‐1). During the survey, daytime hourly Leq noise levels ranged from 51.5 dBA to
69.2 dBA Leq. The maximum noise levels ranged from 71.8 dBA to 97.6 dBA Lmax, which were
caused by OHV passbys within a foot of the sound level meter and aircraft overflights during
periods when OHV recreationists were inactive.
Existing Traffic Noise
Traffic noise is the dominant noise source in the project area and is influenced by major roads
such as Larkin Road and SR 162. Existing noise levels from vehicle traffic in the project area were
modeled using the Federal Highway Administration (FHWA) Highway Traffic Noise Prediction
Model (FHWA‐RD‐77‐108) and traffic data provided by the Clay Pit SVRA General Plan traffic
consultant (KD Anderson & Associates 2011). The FHWA model is based on CALVENO reference
noise factors for automobiles, medium trucks, and heavy trucks, with vehicle volume, speed,
roadway configuration, distance to the receptor, and ground attenuation factors considered. Truck
usage and vehicle speeds on study area roadways were estimated from Caltrans data and from
field observations (Caltrans 2010:251).
Clay Pit State Vehicular Recreation Area
February 2012 3.3-8 Draft EIR