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03i'2212000 16:51 612-341-2124 SIRNY ARCHITECTS PAGE 04 I'IHh' «; �F�v�b k;�i: 4y 1-n L lihF-I�LFM.J HbbUl, b1�.3�14J'!� IU .541L1<:4 H'.4:1Sij� Richard Christet�ca on Midland Hills Cotutty Club Parldo� Lc�t Sound Levels 22 March 2000 Pagc 2 'flic sound level at [he homes has b�:�n estimated assuming only thc decay of sound with d�stancc from th� patklag lot. No atmospheric absorption or attenuation by grassy sucfaccs is assumed. It should also be noted that tTCCS can only provide some meaningful attenuation of noise levels if the uee bolt is both d�nse and deep. For example, to reduce sound leveLs by 3 dHA normally requirw a tree belt that is 100 feet deep and made up of trees with a range of canopy heights. �refon.w'1u1c trees can providevi'ua1 shielding, no ucausucal benefit from crees is assumed in this analysis. In the previuus evaluation of band noise, a background level of 40 dBA was assumed for the area. However. since the greate,st concern vri[h noise from the parking lot would occur very late in the evening when �lie �bient could be lower, a 35 dBA background level is assumed in thi� study. EXHIBIT 2 through EXAIBIT 5 show the estimated �oice levc] at the representative homes identified by address. In EXHIBIT 2(Site 1). the projected sound level is high at �1961 and #2241 becausc they are relatively close but only somewhat shielded by the berm. All of the projected levels are below the �umed 35 dHA background kvel. With more than one loud v�ice at the same instant in time. the level couJd reach 35 dBA at these two sites. Whi]e the voice �nigh� be more audible at these two �ites, audibility will depend upon the background level at any instant in timc. However, the kvek are 20 dBA I�low the Minnesota nighttime standard for short tcrm no�se. luc�zasin�g the berm height by 4feet will reducc thc levcl by over 6 dBA at some sites to below 25 dBA which is 10 dBA belvw �he likely background. Placing a 4-toot fence on top of the barm wig s�lso reduce the noise level u� a similar manner as increasing the berm height, but u slightly ]ess effective sinee it is a reflective r,�cher than au absorptive burier. Wh�e a voice may still be audibk with the u�crcascd berm or feace, audib�lity is not addre�sed in the Minnesota noise standards no 1 any other noise standards or guidelin�s, since sounds may be audible at very low decibel levels. In EXHIBIT 3(Site 2). aU of the levels are somewhat lugh�r since the berm or berm plus Ic�ice combination is not as effecdve. The level at �i1961 ia predictcd to be above 35 dBA ��. this location. Since a berm i� not feusi�ble for shielding this home, a fence of different heights i� evaluated a»d discussed below. In �XH�IT 4(Site 3). sound levels a�ee simila�' to those from Site 2. Howevcr, it can be seen here that the berm and fence �rc less et�ective in shielding sound from this s�te. However, except for#t1961, all of the levels are below 35 dBA, In EXHIBIT S(Site 4), thc sound levels are no longer affected hy the henn or fence, although they :ire predictr.,i to k below 30 d8A exaepc for #1961.