Does the Department accept opacity based emission calculations?
A. No, the Department does not accept opacity based emission calculations. All known opacity based emissions calculations are based on a 1988 technical paper written by D.S. Ensor and M.J. Pilat (Univirsity of Washington) titled “Calculation of Smoke Plume Opacity from Particulate Air Pollutant Properties.” EPA has never adopted or condoned this method of calculating particulate emissions based on the opacity of a particulate plume. Although the Department has accepted this method of calculating emissions in the past, without EPA support of this method, support of this method by other states, and positive academic peer review, the Department has lost confidence in the validity of this method of determining particulate emissions from plume opacity measurements and has determined this method is not acceptable, appropriate, or defensible. The Department will use EPA established AP-42 emission factors for the mineral products industry located at www.epa.gov/ttn/chief/ap42/ch11 .
