pf_02881 - Laserfiche WebLink

Home

.Ma.r. 18, 1997 12:55PM BRAUN INTERTEC CORP No. 3987 P. 7/13 Minnesota Pollution Control Agency Project No. CMXX-97-o142 March 18, 1997 Page 4 Table 3 1999 Post-Development PM Peak-Hour Noise Levels J~._~~~:)-/ " .-!;..... ,',<. ;b' '~...".~ -, . ~~qv~'" .... ~~. ~. ',"-. . : .~'~ .' ~';~'::~' ~ '. . ~ :- -; . :::'~:~.~:,: .;........ -:.....~ . .~>....... -:.....0:..::::. ,.................... .' . . .......1. ~ , 1 64.2 51.7 2 65.0 58.8 3 65.8 60.2 3.4 Noise Impact Evaluation As can be seen in Table 3, there are no exceedances of the noise standards in the post- development scenario of the model. Also, as can be seen in Table 4, there is not a significant increase in noise l~els in the post-development scenario over the pre-deve1opment scenario. The largest predicted increase in noise levels is at Receiver 2 where the predicted ~o and Lso noise level increases are 1.5 and 1.3 dB(A), respectively. However, as previously mentioned) the predicted Lso noise levels at this receiver remain in compliance with the noise sWKIards in Minn. R. ch. 7030. Also, these increases are considered insignificant because the human ear cannot perceive changes below 3 decibels from a time-varying noise source. Tobie 4 1999 PM Peak-Hour Noise Level Change Due to Development i~'~~~~\\ :.-<>~/~.~t41""': ~:~:.~;t~i~:L ::';' ... ....' ',. ~ ... .~:.... . }):' ...:.;:c......:......~~....":u...:..j..~ """"',:..' ,.tfi~ ,-'$. ...' ,... 't~..~' ~ ';~:~~ '. .. ~" t :::.?~:::'~~~:~f.'~::") :~:{~.:~:.~~ ~~ :,::-:.... e::~::": ..::~~~~;::.:.~: 1 +0.2 -0.4 2 + 1.S +1.3 3 -1.3 -3.9 EJtceedances do not occur in the model. However, as a result of incorporating data obtained - from ambient noise monitoring which differs from the 1988 background data used in the model,~e predicted at Receiver(Dmd 2 in the p~t-developm.ent scenario. However, the predicted Lso noise level is ~y 0.4 dB(A) at Receiveg. As can be seen in Table 4, there are also reductions in the predicted noise levels at Receiver 3. The reduced Doise levels at Receiver~ 1 and 3 are due to the attenuation effectS of proposed buildings that would separate these receptors from roadways. Relative to the Minnesota Standards, post- development traffic noise levels are anticipated to be below the PM Lso residential standard [60 dB(A)] at Receivers I and 2, and below the Lto and Lso commercial standards [70 dB(A) and 65 dB(A] respectively, at Receiver 3.