Noise and Vibration Assessment

INTRODUCTIONThis report presents the results of the noise and vibration impact assessment completed for theDingee Backbone Pipeline Replacement Project. The existing Dingee Backbone Pipeline extendsfrom Dingee pumping plant, located in the City of Berkeley to Estates Reservoir located in the Cityof Oakland. The proposed bypass alignment would follow Golden Gate Avenue and BroadwayTerrace, returning to the alignment of the existing backbone pipeline located along Proctor Avenue,Julia Street, and Harbord Avenue. The proposed bypass alignment project would include installationof a new 24-inch to 30-inch diameter pipeline. Additional pipeline improvements, includingrezoning customers on Roble Road and Roble Court in the City of Berkeley from the DingeePressure Zone to the Summit Pressure Zone, would be necessary to maintain customer service. Aregulator would also need to be installed in the Roble Road vicinity to maintain localized customerservice. Another distribution pipeline would be required to replace the 6-inch diameter pipelinelocated along Contra Costa Avenue in Oakland. The pipeline diameters for this ancillary projectwould be 8 inches. Furthermore, new 6-inch to 8-inch diameter pipelines would be necessary toreticulate the proposed backbone pipeline with the existing distribution piping network systems.Connections would occur at the intersections of Golden Gate Avenue with Eustice Avenue, NovaraRoad, Romany Road, Hill Road, Arcadia Avenue, Arbon Path, Buena Vista Avenue, and Erba Path.The noise and vibration impact assessment first presents the fundamentals of noise and vibration forthose who are not familiar with acoustical terminology and concepts. The report then summarizesambient noise conditions in the project vicinity, and provides an evaluation of the potentialsignificance of noise and vibration-related impacts that would result from the project. A list of bestmanagement construction practices is presented to reduce construction noise levels as low asfeasible.SETTINGFundamentals of Environmental NoiseNoise is defined as unwanted sound. Airborne sound is a rapid fluctuation of air pressure above andbelow atmospheric pressure. Sound levels are usually measured and expressed in decibels (dB) with0 dB corresponding roughly to the threshold of hearing. Decibels and other technical terms aredefined in Table 1.Most of the sounds, which we hear in the environment, do not consist of a single frequency, butrather a broad band of frequencies, with each frequency differing in sound level. The intensities ofeach frequency add together to generate a sound. The method commonly used to quantifyenvironmental sounds consists of evaluating all of the frequencies of a sound in accordance with aweighting that reflects the facts that human hearing is less sensitive at low frequencies and extremehigh frequencies than in the frequency mid-range. This is called "A" weighting, and the decibel levelso measured is called the A-weighted sound level (dBA). In practice, the level of a sound source isconveniently measured using a sound level meter that includes an electrical filter corresponding tothe A-weighting curve. Typical A-weighted levels measured in the environment and in industry areshown in Table 2 for different types of noise.Although the A-weighted noise level mayadequately indicate the level of environmental1