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

3.3 Noise
Noise emissions of competition off‐highway vehicles manufactured on or after
January 1, 1998, shall be limited to not more than 96 dBA, and if manufactured prior
to January 1, 1998, to not more than 101 dBA, when measured from a distance of 20
inches using test procedures established by the Society of Automotive Engineers
under Standard J‐1287, as applicable. Noise emissions of all other off‐highway
vehicles shall be limited to not more than 96 dBA if manufactured on or after
January 1, 1986, and not more than 101 dBA if manufactured prior to January 1,
1986, when measured from a distance of 20 inches using test procedures
established by the Society of Automotive Engineers under Standard J‐1287, as
applicable.
For the purposes of this analysis, OHVs operating at Clay Pit SVRA are assumed to generate noise
levels not exceeding 96 dBA at a distance of 20 inches.
To assess potential short‐term noise impacts caused by construction of the project, nearby
sensitive receptors and their relative exposure to the noise were identified. The noise levels from
project construction that could be heard at these sensitive receptors were predicted using the
federal Transit Noise and Vibration Impact Assessment (FTA 2006: Chapter 12).
Regarding project‐generated increases in traffic noise, AECOM created models of noise levels at
affected roadway segments (e.g., Larkin Road) using the FHWA Highway Traffic Noise Prediction
Model (RD‐77‐108) (FHWA 1978) and traffic data (e.g., ADT volumes, vehicle speeds, percent
distribution of vehicle types) from KD Anderson & Associates (2011). This model is based on the
CALVENO reference noise emission factors for automobiles, medium trucks, and heavy trucks and
it accounts for vehicle volume, speed, roadway configuration, distance to the receiver, and ground
attenuation factors. The model does not assume the noise would be shielded by anything natural
or human‐made (e.g., vegetation, berms, walls, buildings). Increases in traffic noise levels
attributable to the project were calculated by comparing the predicted noise levels at 100 feet
from the centerline of the road with and without project‐generated traffic under existing and
cumulative conditions.
Concerning non transportation noise sources (e.g., construction sources) associated with project
implementation, the long‐term impacts caused by project operations were assessed using
reconnaissance data, existing documentation, and standard attenuation rates and modeling
techniques.
To assess the potential exposure of sensitive receptors to and generation of excessive
groundborne vibration and noise levels, sensitive receptors and their relative exposure were
determined by reviewing vibration levels documented for specific sources and using standard
modeling procedures as recommended by guidance from federal and state agencies (Caltrans
2002; FTA 2006).
Clay Pit State Vehicular Recreation Area
February 2012 3.3-16 Draft EIR