Technical Bulletin No. 0100: Estimated Ground Level Concentrations of Sulfur Dioxide and Particulate Matter for Selected Kraft Mill Sizes Using EPA Dispersion Models (AQTB)
The addition of facilities at an existing or new mill site which will emit more than 50 tons/year or more of a criteria pollutant such as particulate matter or sulfur dioxide requires the owner to carry out an ambient air quality modeling program as part of EPA's Prevention of Significant Air Quality Deterioration (PSD) regulations. The first step in this modeling exercise is the use of EPA prescribed models to determine if no more than acceptable portions of the allowable PDS increments are consumed. Based on existing guidance provided by EPA, if no more than 50% of the increment in a Class II area is consumed as determined in the initial modeling exercise, no further modeling is likely to be required. Additional modeling, using more refined models, is likely to be required if more than 50% of the increment is used, or the emissions impact a Class I area. The attached technical bulletin uses the four EPA screening models to determine the fraction of increment usage by a series of representative kraft pulp mill sizes and auxiliary power generation facilities. These include 500 and 1000 ton/day bleached and unbleached kraft pulp mills using various combinations of fossil and wood residues as fuel. Three conditions of terrain surrounding the mill are examined; namely terrain at (a) mill site level, (b) stack height, and (c) plume height. These estimates should be viewed as upper limit values for the array of situations examined. The study showed that terrain features surrounding the mill is the single most important factor in determining the amount of increment consumed.