Document 15yN8nZv1j448Gj0z00Ky5eLj

AR226-2343 ATTACHMENT 1 YEAR 2002 AIR DISPERSION MODELING ANALYSIS OF APFO EMISSIONS DuPont W ashington W orks Facility Parkersburg, W est Virginia Prepared by: DuPont Engineering Technology (DuET) Environmental Section Wilmington, DE 19898 October 17,2003 ASH027176 EXP015741 . Year 2002 A ir Dispersion M odeling Analysis October 17,2003 Page 2 1. Introduction . DuPont conducted air dispersion modeling o f APFO* emissions from its Washington Works facility located near Parkersburg, WV. Modeling was conducted to predict long-term ambient air concentrations o f APFO resulting from actual plant emissions that occurred during calendar year 2002. This report describes the APFO emissions inventory used in die modeling analysis, the meteorological data, die dispersion model and modeling procedures, prediction locations (receptor grid), and die results o f die m odeling analysis. . 2. Emissions Inventory The following em ission inventory information has been assembled in order to conduct the air quality modeling: 1. Stack locations 2. Stack heights 3. Stack diameters 4. Stack gas exit temperatures 5. Stack gas flow rate or exit velocities 6. Detailed plant layout, including all building dimensions 7. Year 2002 estimated actual emissions. These emissions estimates are based upon product information and technical knowledge, including usage factors (quantity o f APFO used per pound o f dry product), production records, APFO recovery, and available stack test data. All o f the stack parameters are presented in Table 1, which shows die source representation for modeling purposes. The estimated actual emission rates o fAPFO, per source, are also presented in Table 1. Figure 1 presents the general locations o fthe APFO sources. 3. M eteorological Data One year of on-site meteorological data for the calendar year 1996 was used in this study. Concurrent twice-daily upper air data from the upper air observation station located in Wilmington, OH was used along with on-site surface temperatures to obtain hourly mixing depths. Missing data and measured wind speeds of less than 1.0 mJs were treated consistent with die recommendations made in the EPA's "Meteorological Monitoring Guidance for Regulatory Modeling Applications . An anemometer height o f 10 meters was used for the modeling analysis. 4. M odel Selection The area surrounding Washington Works is primarily non-urban. The U. S. EPA procedures classify land use within 3 kilometers o f the site by the Auer method p). Previous review o f U. S. Geological Survey (USGS) maps, aerial photographs, and site visits clearly indicated that the area is well over 50% *"APFO" means ammonium perfluorooctanoate, and for the purposes o f this report includes the anion o f the acid perfluorooctanoic acid (PFOA). ASH027177 EXP015742 Y ear 2002 A ir D ispersion M odeling Analysis October 17,2003 Page 3 non-urban. The Washington Works facility is located within the Ohio Rivervalley, and is surrounded by significantterrain features on both sides o f this river valley. As a result, terrain elevations were considered in the modeling analysis. _ * The Industrial Source Complex Short T om Model (ISCST3) was used as the primary model to estimate long-term pollutant concentrations. ISCST3 is a steady-state Gaussian model recommended by the U.S. EPA. It is included in the "Guideline on Air Quality Models'*3*, which is codified as Appendix W to 40 CFR Part 51. It is appropriate for modeling o fpollutant emissions from multiple, industrial-type sources subjectto significant building downwash. The downwash algorithms in the ISCST3 model provide a representation o f the aerodynamic downwash o f a stack plume caused by complex budding configurations typical o f industrial facilities. Refined ISCST3 modeling was conducted using one year (1996) o f sequential hourly meteorology from the from the on-site observation facility, as described above. 5. Receptor Selection A Cartesian grid o f receptors was utilized in this modeling analysis. This grid consisted o fthe following: Fenceline receptors with a 100 m spacing between receptors Receptors beyond the fenceline with 100 m spacing on a 5 km by 7 km gnd All receptors are located along or outside the plantfenceline. A Cartesian receptor grid o fthis type is considerably more dense than recommended by the U.S. EPA in the Guidelines on A ir Quality Models for modeling a facility o fthis type. Terrain elevations for each o f the receptors were imported from electronic files obtained from the U. S. Geological Survey (USGS) using the "highest" method to assign an elevation to each receptor. The receptor grid used in the modeling analysis Is shown graphically in Figure 2. 6. M odeling Procedures The most recent version o fISCST3 (version 02035) was used in the air quality dispersion modeling o f all receptors. All model options were set to the U.S. EPA regulatory default version o f 1SCST3. The model was run in the iurai mode since the land area in the immediate vicinity of Washington Works is more than 50% rural. Any effects o f aerodynamic downwash caused by structures adjacent to the modeled stack were included in the ISCST3 modeling analysis along with a summary o f the building,downwash input files (BPIP). Air quality dispersion modeling was conducted on an hour-by-hour basis using the one year o f meteorological data described above. The APFO modeling results were summarized for foe annual averaging time period. 7. Results The results of the modeling analysis indicate a maximum predicted annual average APFO concentration of l ,36 ug/m3. This maximum is located along the northern property fenceline, along the Ohio River, at UTM 442043 E, 4346883 N . The maximum predicted APFO concentration in an area where people may reside is 0.39 ug/m3. This prediction is located at UTM 442600 E, 4347600 N, on the Ohio side o fthe river. The results are presented graphically in Figure 3. ASH027178 EXP015743 Year 2002 A ir Dispersion M odeling Analysis October 17,2003 ' Page 4 T able 1 SODRCB ID *** POINT SOURCE DATA *** XY (METERS) (METERS) BASE ELEV. (feet) Emission Rate llb/hr) STACK STACK HEIGHT TEMP. (feet) (DEG.S') STACK STACK EXIT VEt. DIAMETER (ft/sec) (feet) CEH242 TIM662 T1E&TIF699 CFS274 R022EEF86 R022EEF89 T1F644 THI652 CDB216 R022EEF6 R022EEF87 TUG658 CFK268 C1CA-0205 CDT231 CDW232 TW097 TIF694 TIE647 T1F648 441954 442025 442091 441787 442069 442063 442084 441920 441960 442086 442058 441923 441774 442310 4419 441952 442129 442104 442125 442109 4346741 4346847 4346836 ' 4346744 4346627 4346635 4346835 4346767 4346788 4348624 4346634 4346756 43487 4346800 43487 4346776 4348836 4346822 4346818 4346805 659.4 638.5 639.8 6562 629.9 629.9 63B.8 649.6 559.4 823.4 629.9 649.6 643.0 656.2 659.4 659.4 658.0 656.0 656.0 665.0 0.1047 0 0.1019 0.3424 0.000034 0.0000 0.4397 0.0037 0 0.0014 0.00034 0.07 0.0071 0 0.3622 0.2628 0.0049 9.50E-03 0. 0.0024 . 114.5 149.9 170.0 109.9 48.9 48.9 59.1 69.9 60.0 46.9 48.9 67.9 72.5 6.7 81.0 93.2 45.0 45.0 69.0 69.0 200.0 172.0 124.0 254.9 80.0 80.0 110.9 200.0 158.1 80.0 80.0 299.9 110.0 70.0 130.0 130.0 68.0 .o 230.0 230.0 106.1 40.2 27.9 44.6 40.0 20.0 169.8 54.1 34.5 30.0 10.0 224. 29.1 84.9 28.4 23.6 15.2 15.2 57.0 57.0 0. 1. 4. 0.69 2. 2. 1.50 1. 1.30 2.50 200 1.63 0.27 0.50 0.67 0.67 1.67 1.67 1.67 1.67 ASH027179 EXP015744 Year 2002 Air Dispersion M odeling Analysis October 17, 2003 Page5 Figure 1 ASH027180 EXP015745 4349000 4348000- 434700043460004345000- + 439001 Year 2002 A ir Dispersion M odeling Analysis October 17,2003 Page 6 Figure 2 j R eceptor Grid U sed in the M odeling Analysis ++++++++++ +4++444 +-44+++++++++4+* ` +++++++++++ +4+4+4+44+++. . + + + + + <+ + + + + + + 4 + 4 + 4 + 4 4 + + + -- + + + + + <++ + + + + +++4++++4+4+ ++ + + + + + + + + + + + + + ++ + + + 44-4 + +++ 4 +++4+44+- 44+444+4 4 4 4 4 +++4 +4 +4 4 4 4 + ++++ +++++44 +- + 44"+ + + 4 + + + + + 4 4 + + -- 4 ++++4+++++4+4 4. + 4. 4 4 . 4 4 4 4 f H>4 . l ++4+++++44++" +++++4++++++* 4 4 + 4 + 4 + 4 4 4 4 4- + 4 + 4 + 4 + 4 4 4++ 4 4 4 + 4 4 4 4 4 4 ++ + + 4 + + + + 4 + 4 + + 1 ++++++4+44+4 +4+ 4 + 4 4 4 + 4 ++ - +++++++++4+4 ++4+++4+++++++4+++44++4+* 4+44++44++44- ++++++++++++ 4+4++4+4+4+4- 4 + 4 + 4 4 + + + + ++ 4+44+44+44+4* 4+44+444+4+4 +4+++4 ++ ++ +++++4++ 4+++4+ - ++4+++++44++' ++++++++++++. + 4 + 4 + 4 + 4 +++4 + 4 + 4 + 4 + 4 +4 4 4 . 4+ 4 4 +4 ++++++ +/4+++ 4+4++++4+++++++++++4++- >>'+ ' ............. 445000 m eters ASH027181 EXP015746 4349000 4348000434700043460004345000- 439001 Year 2002 Air Dispersion M odeling Analysis October 17,2003 Page 7 Figure 3 APFO 2002 Modeled Emissions Annual Average Concentrations (ug/m3) C onto ur Interval 0.1 ug/m3 meters ASH027182 EXP015747 I ' References Year 2002 Air Dispersion M odeling Analysis October 17,2003 Page 8 (1) U. S. EPA, Meteorological M onitoring Guidance for Regulatory Modeling Applications,.EPA454/R-99-005, O ffice o f A ir Quality Planning and Standards, February, 2000. (2) Auer, A. H., "C orrelation o f Land Use Cover with Meteorological Anomalies", Journal o f Applied Meteorology, Vol. 17, pp. 636-643,1978. (3) U. S. EPA- finideline on Air Quality M odels (Revised), EPA-450/2-78-027R-C, 2001. ASH027183 EXP015748