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,Hr Sint' -- P\I?I,� ."cVe1 F'i; # I,"ay 2022 <br /> The proposed gravel extraction operations will not cause the air quality to be reduced below <br /> acceptable levels as established by the Colorado Air Pollution Control Division. There will be <br /> no hazardous material stored or used at the proposed mine. Scott will phase the mining <br /> activities to be less than 100,000 tons during the first year of operations. Scott will size the <br /> equipment requirements during this first year of operation and apply for coverage under an <br /> APEN, if applicable. <br /> 2.12.3 Noise/Vibration <br /> Scott understands that the LUDC, Division 7-1002 for Gravel Extraction, Section C. <br /> Noise/Vibration, specifies noise thresholds per Neighboring Use (see Table 7-1002). The <br /> property to the east has a Residential use and the noise threshold from 7 a.m. to 7 p.m. is 55 <br /> dB(A) and from 7 p.m. to 7 a.m. is 50 dB(A). Scott collected ambient noise levels' on <br /> September 30, 2020, between 12:38 p.m. and 12:45 p.m. at various locations to get the <br /> ambient noise readings from the neighboring interstate. The modeling analysis was developed <br /> to predict operational sound levels at adjacent properties and verify compliance of operations <br /> with the Colorado Revised Statutes (CRS) 25-12-103 noise standards (Figure 8). The <br /> ambient noise level measured at a location on the Rifle Pit#1 property approximately 100 feet <br /> from a point on the north side of 1-70 (Fence) was 55.7 dB(A). This level is equivalent (and <br /> slightly greater) than the Residential use noise threshold for the 7 a.m. to 7 p.m. timeframe. <br /> Scott also took noise measurements from one of their existing operations that would reflect <br /> the proposed operations and equipment for the Rifle Pit #1 (Figure 9). The projected noise <br /> level at the Residential property boundary would be about 70.8 dB(A)assuming the equipment <br /> is placed 200 feet inside the boundary. This projected noise level does not account for the <br /> impact of the perimeter berms to provide noise mitigation. <br /> The net effect of the Scott Rifle Pit#1 operations only is expected to be below the 50 dB(A) <br /> threshold for neighboring residential use. Scott could measure noise levels upon <br /> commencement of mining operations; however, with the ambient noise levels of 1-70, they <br /> would not be representative. Table 3 summarizes the ambient noise data at the Rifle Pit#1 <br /> property. <br /> ' Ambient Noise(per LUDC definition). The total of all noise in a situation,independent of the projected noise from any <br /> new particular source or increase in existing sources of noise. Ambient noise includes both sustained background readings <br /> and existing fluctuations in noise levels. <br /> 2-19 <br />