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Ma,r. 18. 1997 12:55PM BRAUN INTERTEC CORP No. 3987 P 6/13 Minnesota Pol1ution Control Agency Project No. CMXX-91"()142 March 18, 1997 Page 3 3.1 Minnesota Noise Standards Minnesota RIlles Chapter 7030 provide the Minnesota standards for noise. These standards describe the limiting levels of sound established on the basis of present knowledge for the preservation of health and welfare. These standards are designed to be consistent with .sJeep, speech, annoyance, and hearing conservation requirements for receivers within areas grouped according to land use activities, The Minnesota standards are as follows: Table 1 Minnesota Noise Standards (Decibels - A Scale) 7:00 a.m. to 10:00 p.m. LID Lso 10:00 p.m. to 7:00 a.m. LlG Lso NAC-l (Residential) NAC-2 (Commercial) NAC-3 (Industrial) 65 70 80 60 6S 75 55 70 80 50 65 75 LlD means the sound level which is exceeded for 10 percent of the time for a one-hour period. Lso means the sound level which is exceeded 50 percent of the time for a one-hour period. Sound levels are expressed in dB(A), which is a unit of sound level expressed in decibels and weighted for the purpose of determining the human response to sound. 3.2 Noise Receptor Loc.atioDS Three noise receptor locations were chosen for this project. Receivers 1 and 2 are located in the residential area along Cleveland Avenue east of the proposed. site. Receiver 3 is located in a commercial area on the southwest portion of the site representing an office/showrooIll building location. 3.3 Noise Model Results Tables 2 and 3 provide the results of noise modeling for the pre- and post-development scenarios: Table 2 1999 Pre-Development PM Peak"Hour Noise Levels ;~:~:..::O(Ai~.':',:.~~ '~~aB(!, ' ., ~".., . .' . '.. '. ... ~ '.< .'.. , ,..'., '. ~;~;,~,;; :.:. :: .... :: ':.'~~'. 0:' :; ...... .... : .......... t:: " '.. ....... :..;........ :. .)., ...-:.....:...... ':....... ::-0':-":'<: 1 64.0 58.1 2 63,5 57.5 3 67.1 64.1