Document xzNLXOE5y2rLQD4DzVwOYQ2BE
AR226-2657
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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 yearofon-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 of 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.
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Modeling Results
An averaging time of 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 jig/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
PennitAmendments.dat PermitAmendments.lst PermitAmendments.bpi PermitAmendments.bpo pkbiln96.asc
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Table 1 Stack Parameters
815E (815D) Deep Bed Scrubbei815E(815D)D1 Cooler 815E(815D)D3Cooler 1353B(1353A)Dryer2 1353B (Pro-Existing) Dryer 1 1953A(614A)Dryer 1 2365B (2365A) Dryer 2365B (2365A) Filter/Receiver
Semi-works Applic
T6IZCE
699
T61XE
697
T61YE
694
164-5E
652
164-2E
658
163-E-26
231
C1FSE
274
C1FKE
268
Research
4
1.22
170
51.8
21,000 27.9
8.5
1
1.67 0.51
45
13.7
2,000
15.2 4.6
1.67 0.51
45
13.7
2,000
15.2 4.6
1.96 0.60
70
21.3
9,800
54.1
16.5
2
1.63 0.50
68
20.7
2,800
22.4
6.8
3
1
0.31
100 30.5
3100
65.8 20.1
1
0.69 0.21
110 33.5
880
39.2 12.0
1
0.27 0.08 72.5 22.1
100
29.1
8.9
1
2.5
0.76
47
14.3
8,836
30
9.1
Table 2 Stack Locations and Emission Rates
815E (815D) Deep Bed Scrubber 815E(815D)D1 Cooler
815E(815D)D3Cooler 1353B(1353A)Dryer2 1353B (Pre-Existing) Dryer 1 1953A (614A) Dryer 1 2365B (2365A) Dryer 2365B (2365A) Filter/Receiver Semiworks Applic
T6IZCE
699
T61XE
697
T61YE
694
164-5E
652
164-2E
658
163-E-26
231
C1FSE
274
C1FKE
268
RESEARCH
442091 4346836
195
442129 4346836
194
442104 4346822
195
441920 4346767
198
441923 4346756
198
441941 4346758
201
441787 4346744
200
441774 4346753
196
442086 4346624
190
3,258 3 3 94
70.6 2754 1,327 360
16
4.69E-02 4.32E-05 4.32E-05 1.35E-03 1.02E-03 3.96E-02 1.91E-02 5.18E-03 2.29E-04
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4346900-H
434680(M 4346700-^
434660CH
43465(KH 441600
441700
441800
441900
442000
Figure I - Building Plot Plan
Figure 1 Building Plot Plan
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442100
4346850---] 4346800----
4346750----
4346700441850
441900
441950
442000
442050
Figure 2 Building 162/163 Detail
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43490004348000-
4347000- -0
43460004345000-
439000
440000
441000
442000
443000
444000
Figure 3 Predicted Annual Average Concentrations (p,g/m3)
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