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` <br />Mr. Kevin Kaln ����� � <br />Mr. Tarik Hanafy MOSS (X Barl�ett <br />September 10, 2010 <br />Page 5 <br />The EPA has compiled emission factors for a wide variety of processes including asphalt plants <br />such es the proposed Rosevllle Bftuminous Roadways Plant <br />Current AP-42 factors for asphalt plants are based on tests from approwmately 275 emission <br />test reports. Many of these tests irrvolve multiple test runs at the same faclliry (usually 3). <br />Tests at a single facility may vary by several percent and test resulis between iadlities may vary <br />by orders of magnitude. Averaging together multiple test results from seve2l facilities can <br />provide a reasonable estlmate of emisslons from vartous processes. <br />'Ihe EPA rates emission factors from A(Excellent) to E(POOr). For criteria pollutants the <br />emission factor ratings at asphalt plant sources ranged from A to C. Emission factor ratlngs for <br />non-criteria pollutants at asphalt plarrt sources ranged from C to E, <br />None of the asphaft plant processes tested for development of the AP-42 emissions factors used <br />carbon beds or fiber bed filters to control emisslons. None of the AP-42 tesCS tested for <br />hydrogen sulfide so there are not EPA approved emissions factors For hydrogen sulfide <br />emissfons from asphalt plants. To estlmate emissions from these processes and to estimate <br />hydrogen sulfide emisstons hom the proposed Bitumfnous Roadways Roseville Plant, Bftuminous <br />Roadways relies on tests rnnducted by the Natlonal Asphalt Pavement Assodatlon and the <br />North Carolina Department of Environment and Natural Resources Divisfon of Afr Quality. <br />The wfde variation in test rasults between different tests and between difFerent asphalt plants <br />and asphaR plant processes make ft very difficult to generalize tests from one lacility to another � <br />facfltry and hom one process to another praess. Several faaors may contrlbute to this <br />variance. Compositlon of the asphalt cement, fuel type, plant mfxing temperature, moisture <br />content of recycled asphalt pavement (RAP) and aggregates, use of materials containing coal <br />tar, use of slag aggregate, shingles, crumb rubber mUctures, products from construction and <br />demolltion waste, calibration oF sensors, tun(ng of the burner, pollutlon control equipment <br />mafntenance, and ambfent conditio�s. Dab may also vary due to use of different test methods. <br />Besides various operating conditions, the compositlon of asphak can vary considerably. We <br />revlewed several Material Safety Data Sheets (MSDSs) fw asphalt from around the counUy. <br />The listed hydrogen s�tfide content ranges from neglfgible to 0.5°/a and the suifur content in the <br />asphait ranges from 0 to 7%. A hfgh sulfur asphalt will have higher levels of hydrogen sulfide <br />and aould produce up to flve tlmes as much hydrogen sulfide emissions as a low sulfur asphalt. <br />This difference could materially affect the odor and health impacts of the proposed asphalt <br />p�ant project. <br />Without knowi�g the sulfur and hydrogen sulfide content of the asphalt in North Carolina and <br />the asphalt used by Bituminous Roadways, It is hard to see how the data from one site can be <br />used to reliably predict emissions from another site without knowing all of the significant <br />vartables. We also do not know the percentages of other materials such as RAP, shingies, and <br />construction waste (and their molsture content) used during the NorYh Carolina tests and how <br />this compares with the proposed Bituminous Roadways Rose�qile facfOty. <br />� <br />