Laserfiche WebLink
7 <br />Sound Monitoring <br />The existing sound levels were measured at three locations where existing <br />residential properties were located near impacted roadways. The locations of the <br />three monitoring sites are shown on Figure 24-1. The results of the measurements <br />are shown in Table 24-3. The results indicate that in many cases, the existing sound <br />levels exceed the State noise standards. <br />Table 24-3: Sound Level Monitoring Results <br /> 7 <br />00 <br />9 <br />00 AM 66 <br />0 61 <br />5 <br />1 12-Jul : <br />- <br />: 63.5 . 60:9 . <br /> 4 <br />00 PM <br />00 <br />6 63 <br />8 61 <br />1 <br /> : <br />- <br />: 64:8 . 6°:5 . <br /> 7 <br />00 <br />9 <br />00 AM ' 66 <br />5 ' 7 <br />60 <br />2 12-J <br />l : <br />- <br />: 64 <br />9 . 59 <br />5 . <br /> u 4 <br />00 <br />6 <br />00 PM 7 <br />68 63 <br />8 <br /> : <br />- <br />: 70.2 . 64.0 . <br /> 7 <br />00 <br />9 <br />00 AM ' 67 <br />0 60 <br />1 <br />3 12-Jul : <br />- <br />: 64 <br />$ . 60.1 . <br /> 4 <br />00 <br />6 <br />00 PM 71 <br />3 0 <br />65 <br /> : <br />- <br />: 7~.7 . 64:7 . <br />Cells that are bold indicate that the measured sound levels exceed State standards. <br />Sound Modeling <br />The traffic noise impacts associated with each scenario were assessed by modeling <br />noise levels at the receptor sites likely to be most affected by the proposed project.. <br />Three receptor locations were identified to correspond with the three locations <br />where existing sound levels were monitored. Site 1 is located near Yale Street and <br />represents the existing single-family homes at this location. Site 2 is located near the <br />intersection of Twin Lakes Road and 171st Lane, and represents the apartments and <br />townhomes located nearby. Site 3 is located along Twin Lakes Road and represents <br />the townhomes and single-family homes to the northeast. <br />Noise modeling was completed using the noise prediction program MINNOISE, a <br />version of the FHWA STAMINA 2.0 model adapted by MN/DOT and approved by the <br />Minnesota Pollution Control Agency (MPCA). This model uses peak hour vehicle <br />volume, speed, vehicle class, and the typical characteristics of the roadway being <br />analyzed to estimate traffic noise levels. In all MINNOISE models, an alpha factor of <br />0.5 was used to represent the soft ground in the area. No shielding factors were <br />used. <br />The model was used to estimate traffic noise at the receptor sites for five scenarios: <br />Existing (2011), No Build (2031), Scenario 1 (2031), Scenario 2 (2031), and <br />City of Elk River <br />Draft Alternative Urban Areawide Review <br />August 2011 <br />Page 83 of 90 <br />~i <br />~i <br />