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RECYCLED '4 AR226-2657 AR226-2657 ISC Modeling Methodology and Results Introduction This report summarizes dispersion modeling that was completed in support of anticipated updates to R13 permits 1953A and 2365B at the DuPont Washington Works site. Emission Source Information Table 1 shows the stack parameters used in the model and Table 2 shows the locations and emission rates for each emission point. Note that two emission points from previous modeling (242 and 163-E-l 1) have been removed from the model and emission point 163-E-26 has been relocated. Modeling Methodology Dispersion and deposition modeling was performed using EPA's Industrial Source Complex 3 Model (ISC3), version 02035, provided by Trinity Consultants. All modeling was done in accordance with the procedures in EPA's Guideline on Air Quality Models (40 CFR Part 51, Appendix W). The EPA regulatory default options and rural dispersion coefficients were selected in the model. The APFO emission sources were evaluated for downwash effects from surrounding buildings. EPA's Building Profile and Input Program (BPIP) was used to provide wind direction specific building parameters. All buildings on the site were evaluated to determine if they could potentially impact the stack by causing building downwash effects. Plot plans showing the location of buildings included in the model are shown in Figures 1 and 2. (The buildings . included in the model are identical to the list submitted under Consent Order GWR-2001-019). A 100-meter grid extending out 4,000 meters from the source was used. In addition, discrete receptors with 100-meter spacing were placed on the plant property line. Terrain elevations were imported from electronic files obtained from the U.S. Geological Survey using the "highest" method to assign an elevation to each receptor. One year o f on-site meteorological data (1996) was analyzed. The data was processed by Trinity consultants, using Wilmington, Ohio for the upper air data. The precipitation data used is from the Parkersburg, West Virginia airport. Missing data and measured wind speeds o f less than 1 m/s were treated consistent with the recommendations made in EPA's On-site Meteorological Program Guidance for Regulatory Modeling. An anemometer height of 10 meters was used for the modeling. 1of 6 1/28/04 Modeling Results An averaging time o f one year was used to determine the annual average ground level concentrations over the entire receptor grid. A contour plot of these concentrations is shown in Figure 3. The maximum annual average ground-level concentration predicted by the model was 0.410 ig/m3. This concentration occurred at a receptor located on the plant fenceline north of the plant. Electronic Files This report and the following electronic files were transmitted by email to Chris Arrington at WVDAQ on January 28, 2004: ISC Input file ISC Output file BPIP Input file BPIP Output file Meteorological Data file PermitAmendments .dat PermitAmendments .1st PermitAmendments.bpi PermitAmendments.bpo pkbiln96.asc 2 of 6 1/28/04 Stack Nam e 815E (8151.)) Deep Hal Scrubber 815E (815D) D1 Cooler 815E (815D) D3 Cooler 1353B (1353A) Dryer 2 1353B (Pre-Existing) Dryer 1 1953A (614A) Dryer 1 2365B (2365A) Dryer 2365B (2365A) Filter/Receiver Semiworks Applic Table 1 Stack Parameters Em ission lieg 29 uP o-inizt nID. \ c n l 11) (DO T61XE 697 T61YE 694 164-5E 164-2E 652 658 163-E-26 231 Cl FSE 274 C1FKE 268 Research Diam eter (ft) (m) 4 1.22 1.67 0.51 1.67 0.51 1.96 0.60 1.63 0.50 1 0.31 0.69 0.21 0.27 0.08 2.5 0.76 H eigh t (ft) (ni) 170 51.8 45 13.7 45 13.7 70 21.3 68 20.7 100 30.5 110 33.5 72.5 22.1 47 14.3 Flow Kate (acfm ) 21,000 2,000 2,000 9,800 2,800 3100 880 100 8,836 V elo city (ft/s) (m/s) 27.9 8.5 15.2 4.6 15.2 4.6 54.1 16.5 22.4 6.8 65.8 20.1 39.2 12.0 29.1 8.9 30 9.1 1 e in p e r a tu r c 0 ;) ' (K) 124 324 66 292 66 292 200 366 300 422 131 328 130 328 110 316 80 300 Table 2 Stack Locations and Emission Rates Stack Nam e s 151 (N151); Deep BeO v i libber 815E (815D) D1 Cooler 815E (815D) D3 Cooler 1353B (1353A) Dryer 2 1353B (Pre-Existing) Dryer 1 1953A (614A) Dryer 1 2365B (2365A) Dryer 2365B (2365A) Filter/Receiver Semiworks Applic F mission Keg 29 P o i n t II) \ e n t 11) T61ZCE mm T61XE 697 T61YE 694 164-5E 652 164-2E 658 163-E-26 231 Cl FSE 274 C1FKE 268 RESEARCH Stack 1 ocarion i i m - i: I'TiM-X 442091 4346836 442129 4346836 442104 4346822 441920 4346767 441923 441941 441787 4346756 4346758 4346744 441774 4346753 442086 4346624 E le\ alioti (m ) 195 194 195 198 198 201 200 196 190 A P I () A llo w a b le Em ission Kate (lb/yr) (g/s) 3,258 4.69E-02 3 4.32E-05 3 4.32E-05 94 1.35E-03 70.6 1.02E-03 2754 3.96E-02 1,327 1.91E-02 360 5.18E-03 16 2.29E-04 3 of 6 1/28/04 124 Figure 1 Building Plot Plan 4 of 6 1/2 .'04 Figure 2 Building 162/163 Detail 5 of 6 1/28/04 Figure 3 Predicted Annual Average Concentrations (jtg/m3) 6 of 6 1/28/04