10/10/2001 P&Z Packet - Laserfiche WebLink

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• • • Molin Concrete October 10, 2001 page 10 14. The Interim Use Permit will expire if there is a change in the land use in the LI District. comment: This is not an issue to date. The approved storage activities continue. Noise Excerpts from MPCA rules are listed below with comments following them. MN Rules 7030.0020 DEFINITIONS Subp. 7. L10. "L10" means the sound level, expressed in dB(A), which is exceeded ten percent of the time for a one hour survey, as measured by test procedures approved by the commissioner. Subp. 8. L50. "L50" means the sound level, expressed in dB(A), which is exceeded 50 percent of the time for a one hour survey, as measured by test procedures approved by the commissioner. MN Rules 7030.0040 NOISE STANDARDS. Subpart 1. Scope. These standards describe the limiting levels of sound established on the basis of present knowledge for the preservation of public health and welfare. These standards are consistent with speech, sleep, annoyance, and hearing conservation requirements for receivers within areas grouped according to land activities by the noise area classification (NAC) system established in part 7030.0050. However, these standards do not, by themselves, identify the limiting levels of impulsive noise needed for the preservation of public health and welfare. Noise standards in subpart 2 apply to all sources. Subp. 2. Noise standards. Noise Area Classification Daytime Nighttime Lso L10 L50 L10 1 60 65 50 55 2 65 70 65 70 3 75 80 75 80 Residential land use is in Noise Area Classification 1. The measurements are to be taken at the location of the receiving use: in this case, the residential property. That is, noise generated by one use should not exceed the limits when measured from the other use. As can be seen from these definitions, a test must be able to determine if the specified decibel level is exceeded for 10% of the time for one hour, or for 50% of the time for one hour. Daytime in defined as 7:00 am to 10:00 pm, night time as 10:00 pm to 7:00 am.