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Substituting these values into Equation 2, the PMIo emission factor for this traffic level is 1.277 <br />lb/VMT. Daily uncontrolled PMIo emissions from the unpaved section of the road are found by <br />the following: <br />PMIo emissions (lb/day) = daily trips * road length (miles) * PMIo emission factor (lb/VMT) <br />The number of daily trips (539) multiplied by the length of the unpaved section (3.924 miles) <br />and the PMIo emission factor (1277 lb/VMT) results in 2,701 lb/day (uncontrolled) of PM10 <br />emitted from the unpaved surface. <br />Peak Trafflc Level <br />Silt and moisture contents of the unpaved road surface are estimated as previously described. <br />Average vehicle speed at the Peak traffic level is calculated as: <br />312 transport truck trips @ 25 mph <br />15 delivery truck trips @ 35 mph <br />334 employee vehicle trips n, 35 mph <br />661 total trips @ 30.28 mph average <br />Using Equation 2, the PMIo emission factor is 1.266 lb/VMT. Daily PMIo emissions are further <br />calculated at 3,283 lb/day (uncontrolled) for this traffic level. <br />It is reported that the unpaved road section is periodically treated with magnesium chloride and <br />water for dust control. MMA is not aware of the specifics of these actions (the frequency of <br />treatment, the quantity of water applied, etc.), so a precise control factor cannot be determined. <br />However, a control factor of 50% is generally used to account for road dust mitigation resulting <br />from periodic watering. The 50% control factor is used here in the absence of site-specific <br />information. Thus, the controlled PMIo emissions from the unpaved section can be refined to <br />1,351 lb/day for the Year 2014 traffic level and 1,642 lb/day for the Peak traffic level. <br />We also understand that subsequent to this study's initiation, road surface improvements have <br />been made near a number of resident locations. Again, specifics of the road upgrades are unclear <br />and no adjustments have been made in this analysis to reflect these improvements. <br />9250 East Costilla Avenue 1 Suite 630 1 Greenwood Village, Colorado 80112 7 <br />303/790-1332 1 Fax 303/790-7820 <br />www.mevehil-monnett.com <br />