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� Mr. Kevin Kain �� Mr. Tarik Hanafy September 10, 201� Moss & Barnett Page 8 not work zs it begs this cridcal issue and allows the asphatt plant to become estabiished with a tacit understanding regarding the efficacy of the corrtrol technology. The entire undertaking ultimatery relies on conclusions that pollutlon eifects can be deaft with, but there needs to be a' direct showing that this in fact can be done and wili be done. The permitting process and environmental study should be complete before there is any forward movement with the projed. Fiberbed — CE002 The proJect contemplates using a flber bed fiRer to handle VOC and condensable PM. The analysis of the efficacy of the technology requires further work. The hot mix asphalt piant silo emissions wfll be routed to a fiber bed filter to reduce VOC and conder�sable PM. Bituminous Roadways also proposes to use a hood to capture hot moc asphalt load-out emissions and route them to the fiber bed. These fiter beds are designed to rnntrol 'biue smoke' firom asphaR operatlons and Thus reduce the opadty of the exhaust from asphalt plant processes. Fber bed filter mist rnllectors are used to trap, col�ect and remove Uquids and soluble pardculate suspended in a gas stream. They are also used to collect insotuble solids. The emissions calculaUons used in the modeling and the AERA assume a 60% capture efficiency for the hood. The permit applicatlon documents do not indicate how this ppture efflclency was derived. A small diffelence in capture efficiency can make a siqnificant difference in aIr emisslons. The calculations for the filter bed assume 95% control for all pollutants except for carbon monoxide, bromomethane, carbon disulfide, chloromethane, formaldehyde, methane, acetnne, ethylene, and hydrogen sulflde. Several fadors determine achial filter bed effectiveness and efficiency, induding characteristics of the filter media and the adsorbate, the conditions under which they react, ambient temperatures, process temperatures, eftiuent concentraUons, containment of breakthrough emissions, particle size, recovery of desorbed organics, etc. The polarity of the filter media and the adsorbate influence efficierxy as does the molecular weight, vapor pressure, and condensation temperature of the adsorbate. B'ituminous Roadways has provlded an example manufacturer's data for a fliter bed that Includes a list of diemlpls that the fifter bed can control at ope2ting temperetums, may control at filter bed temperatures, and will not control at filter bed temperatures. The molecular welghts, condensation temperdtures and vapor density of the chemicals Iisted that the filter bed can rnntrol vary slgniflcantly. Thls vaHability should be accounted for in the emissions calculaUons, the modeling and the AERA. In addidon, the calculations assume a 95% control for phenanthrene, carbon dlsulfide, methylene chloride, and trichioromethane. The manufacturer Iists these as chemicals that may condense at filter bed operaUng temperatures, but does not indicate at what rete. These should be either changed to 0% con[rol in the calculatlons or Bltuminous Roadways should use a lower efficiency rate based on [es[ data provided.