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HomeMy WebLinkAboutSE202100033 Application 2021-09-13•>)41;((► A C E N T E C H October 16, 2020 Patrick May R. A. Yancey Lumber Corporation 6317 Rockfish Gap Turnpike Crozet, VA 22932 Subject Stacker Activity Sound Levels, Acentech Project No. 630191 Dear Mr. May: 215C ,. Charlw: acentech.com On October 15, 2020 we visited your site to observe and measure the sound from the stacker. We see that you have completed the building surrounding the stacker, including sound absorbing insulation on the walls and ceiling and a clear vinyl barrier at the lumber entry side of the building. We understand that the lumber entry may eventually not need the vinyl barrier and will instead tie into the future building surrounding the sorting equipment that will feed the stacking equipment. As we have noted in previous reports, the Albemarle County Code includes regulations for noise in chapter 18. section 4.18. These regulations define the daytime sound level limit as 60 dBA and outline the procedure to measure the total and ambient sound levels, and subsequently calculate the source sound level. The primary goal of the visit was to determine if the stacker operations are within the daytime sound level limit. We understand that normal operations of the stacker accommodate a variety of lumber sizes, with the heavier 6"x6" lumber generating the greatest amount of sound and lighter 1" thick lumber generating the least. The test condition included the temporary shutdown of all mill operations, to eliminate the generation of all exempt sounds (transportation and warning devices), and allow for measurement of just the stacker operation and other non -mill related ambient sounds. The larger 6"x6" lumber was loaded onto the stacker assembly to generate the worst -case operation, the stacker was switched on, and then the required 5-minute measurement period began. Immediately following this total sound level measurement, the stacker was switched off and a 5- minute ambient sound level measurement was made. Sound levels were measured near the closest property line, on the mill side of the new fence you built to help block sound from your neighbors. Subtracting the measured ambient sound level from the total sound level results in a source (stacker) sound level of 57 dBA, which is below the county's 60 dBA limit. The following table shows the sound levels measured and calculated from the test. Note that ambient sounds included nearby road traffic, air traffic, wind, and leaves rustling in the trees. All sound measurements were made using an ANSI Type 1 compliant Sound Level Meter, both field calibrated prior to the measurement and within the required 1 year laboratory calibration period. Ambient Sound Level Source Sound Level 59.8 dBA 56.5 dBA 57.0 dBA CONCLUSION Based on these measurements, using the heaviest lumber (loudest operating condition), the Stacker generated sound at the closest property boundary was below the daytime sound level limit and in compliance with the noise regulations. Sincerely, Acentech Incorporated Bill Yoder Senior Staff Scientist acoustics av/it/security vibration