2012-0920 Regular City Commission Meeting

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Summary Minutes:Regular City Commission Meeting September 20.2012 City of Sunny Isles Beach,Florida drops off. They also took measurements in the center of the Park during operational conditions to establish what ambient sound level we are going to input into the model and once it is in the model, it will predict from that source point of 68.8 what that relevant sound level will be at all the different receptor points at the varying elevations. The highest number was 68.8 and that represented 9 to 12 skateboard users with interaction with the concrete, pavement, rail, coming down hard, etc. The sound level exceeded 10% of the time. Mitigation options includes three (3) different possibilities: Design Option 1: started with a 230-foot wall that ran along the Skate Park,about 20 feet high,what becomes problematic is that you have receptor points at elevated balconies far above the Skate Park, obviously we can't build a wall 190 feet high and so they looked at 20 feet as the base, and the cost is $470,000; Design Option 2: they put in two flanking walls,a 10-foot high wall that tied into the concession stand, and a 100-foot wall,that is in two sections,to try to assist unit 1519 to get that western exposure to get rid of that flanking noise, with a cost of$695,000; and Design Option 3: which is the best option, not because it is the most expensive at$890,000, but because with higher elevations all the way up to the 23rd floor,that sound wave no matter how high the wall is, has an opportunity to go over the top of the wall, and the only way to get rid of the refraction over the top of the wall would be to have some type of exposure to trap that sound and push it back away from the receptor point, and so we have a 12-foot high wall for Design Option 3 with two feet high of acoustical louvers on top,and so it is in effect a 14-foot high wall. The louvers would assist in sound reduction by allowing some type of ventilation in the Skate Park. Mayor Edelcup said then the biggest reduction only occurs at the Skate Board Park and the Pool Deck,and Mr. Kinney said yes because of the close proximity locations,and the natural ambient is playing an important role in the overall sound. Commissioner Aelion said regarding typical sound level, the noise urban area daytime which is basically the regular traffic,etc. is at 70,and he doesn't see any variance of effect between the three options as far as the mitigated effect. They are nominal here and there but compared to the cost variance, between R1A to R7 there is almost no difference between the options as far as the sound effect is concerned. He said the Commission allowed the study to go forward in order to find a solution to mitigate the sound that is there which is bothering mainly the 600 and 300 building residents (Winston Towers) but from the results, worst case scenario, it equates to noise urban area daytime. He fails to see a substantive argument here unless there is something that has not been presented to us,evidence of allowing ourselves to implement the data here to make a educated decision to go forward. Commissioner Scholl asked regarding the relations of a decimal reading, is it linear or is it exponential? If we plot it, is it a straight line or is it a curve,and Mr. Kinney said logarithm. Commissioner Scholl explained that this means that if it goes from 50 to 60, that 10 is not proportional to the first 50, which means that 10 is larger than the first 10 in the 50. In other words a curve would go like that, and so it is deceiving when you look at the numbers because ultimately going from 60 to 80 is a lot bigger than going from 40 to 60. We need to be careful interpreting the data, it is not a percentage, it means it went up 5 points just like that, it didn't go up 5 points on a straight line, there is a big difference between the two. Really what the report is telling us is that the proposed solution does not work well for what our concerns are and it does not address the problem with the noise at the Skate Park. 25