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The same emission factor is applied to all materials - aggregate, asphalt, and concrete. Clearly, the moisture content would vary among these materials. Thus, more than one emission factor should be used to accommodate the differences. _ Third, this emission factor applies every time a material is handled. The Draft EIR assumes all materials are handled only once. This is unlikely. The various materials 6-35 would be handled multiple times. Fourth, the calculations assume 75 percent control cont with no discussion of how it will be achieved or any requirement that it actually be achieved. This is an extraordinarily high control efficiency for handling and storage achieved using watering, the only fugitive dust control measure mentioned in the — Draft EIR. (Draft EIR, p. 3-15.) Again, we were unable, given the time constraints, to untangle these various messes and determine what the handling and storage emissions should be. IV.D.4 Quarry Processing PM 10 Emissions _ The quarry processing emissions — from various feeders, conveyors, screens, washers, and crushers — were incorrectly calculated in the Draft EIR. The Excel spreadsheet in Exhibit 1 (Estimated PM10 Emissions from Quarry Processing Operations - Baseline) calculated that the quarry would operate 500 hours per year, assuming a design rate of 8,000 tons per hour and an annual production rate of 4.0 million tons. The 500 hours were then accidentally treated as days and used to calculate annual emissions in tons per year. Notwithstanding this error, the fundamental approach used to calculate quarry emissions is flawed. The calculations first assume a production rate, in this example 4.0 million tons/year. The Draft EIR offers no explanation for this choice, 8 36 simply stating it as fact. (Draft EIR, pp. 2-1, 3-8.) Justification is warranted because the capacity of the facility (8,000 ton/hour operating up to 24 hr/day 6 days per week), the operating lifetime of the mine (26 to 60 yrs), and the size of the in-place resource (Draft EER, Table 3-1, p. 3-19) suggest that a far larger production rate is reasonably foreseeable. Next, the design hourly production rate is used to calculate the number of days per year the quarry would have to operate (the erroneous calculation) to meet the target production level (4.0 million tons/yr). The _ assumptions used to calculate the annual throughput should have been disclosed in the Draft EIR. The choice of 4.0 million tons per year underestimates emissions from sources calculated using emission factors expressed as pounds per ton (e.g., emissions from handling &storage, loadout, storage tanks), but not quarry processing emissions (due to the offsetting hour-day error discussed above). It also underestimates traffic and noise impacts. 26