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V %./ URS • Outside of the laboratory, a three dBA (increase or decrease)(sicjis considered just noticeable; • An increase or decrease of at least five dBA is required before any noticeable change in community response would be expected; and • A ten dBA increase is subjectively heard as a doubling in loudness and would almost certainly cause adverse change in community response... " Furthermore, according to the numerous surveys and modeling exercises conducted to develop the county noise element, it is apparent to the county that traffic noise is the main reason for the exceeding the CNEL and that the 50dBA level is not obtainable in area near State Route 99 (99). The subject property is located approximately 2,800 feet from 99 and the impact from the traffic was quite evident and readily perceived during all hours of the sampling period. It should be noted that during the sampling event on December 12, 2000 various daily activities not associated with Premier Environmental Services, Inc. were recorded that significantly contributed to the overall day —night levels. Of notable impact were the sound pressure readings related to the local school bus performing daily pick-up and drop off activities, a garbage truck, a Fed-Ex delivery truck and a cable truck conducting normal activities, a neighbor moving material around their yard, dogs barking and the use by a neighbor of an impact wrench. These activities will be further discussed in the 70dBA maximum section. The data collected (1,456 minutes total) during the January 15-16,2001 event is considered a "heavy" activity day with the addition of a scheduled delivery of materials. Deliveries of this magnitude are anticipated to be infrequent and for a short duration. In order to obtain representative data the M-27 dosimeter was pole mounted at a height of approximately 6-feet orientated about 70° horizontally at the comer of the receptors rear yard and entrance to Premier storage and preparation area yard. The meter was placed to record any traffic that would ingress or egress the yard at a distance of approximately three feet from the source. Based on the 10-minute histograms, the data reflects similar percent noise statistical distributions. The data indicates that 60.10% or 875 minutes out of 1,456 minutes were at or below 50dBA, 22.53% or 328 minutes out of 1,456 minutes were between 50dBA and 55dBA, 6.56% or 95 minutes out of 1,456 minutes were between 55dBA and 60dBA, and 10.17% or 148 minutes out of 1,456 sampled minutes were above 60dBA. Noise Survey Report 3 Premier Environmental Services, Inc 01/31/01