Document N3NO53GbapdMxymr5emVMmnQ

AR226-2344 ATTACHMENT 2 SEPTEMBER 2002 THROUGH AUGUST 2003 AIR DISPERSION MODELING ANALYSIS OF APFO EMISSIONS DuPont Washington Works Facility Parkersbwg, West Virginia Prepared for: West Virginia Department of Environmental Protection Division of Air Quality 7012 MacCorkle Ave, SE Charleston, WV 25304-2943 Prepared by: DuPont Engineering Technology (DuET) Environmental Section Wihnington, DE 19898 October 17,2003 ASH027184 1. Introduction September 2002 Through August 2003 Air Dispersion Modeling Analysis ofAPFO Emissions October 17,2TO3 DuPont conducted air dispersion modeling ofAPFO* emissions from its Washington Works facility located near Parkersburg, WV. Modeling was conducted to predict long-term ambient air concentrations of APFO resulting &om actual plant emissions that occurred during the period of September, 2002 through August, 2003. This report describes the APPO emissions inventory used in uie modeling analysis, me meteorological data, me dispersion model and modeling procedures, prediction locations (receptor grid), and me results of the modeling analysis. 2. Emissions Inventory The following emission 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. Sept 1,2002-Aug. 31,2003 estimated actual APFO emissions All of me stack parameters are presented in Table 1, which shows the source representation for modeling purposes. The estimated actual emission rates ofAPFO, per source, are also presented in Table 1. Figure 1 presents me general locations ofthe APFO sources. 3. Meteorological Data One year ofon-site meteorological data for me 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 m/s were treated consistent with the recommendations made in the EPA's "Meteorological Monitoring Guidance for Regulatory Modeling Applications"^. An anemometer height of 10 meters was used for the modeling analysis. 4. Model Selection The area surrounding Washington Works is primarily non-urban. The U. S. EPA procedures classify land use within 3 kilometers of the site by the Auer method. Previous review ofU. S. Geological Survey (USGS) maps, aerial photographs, and site visits clearly indicated that the area is well over 50% non-urban. The Washington Works facility is located within the Ohio River valley, and is surrounded by significant terrain features on both sides of mis river valley. As a result, terrain elevations were considered in the modeling analysis. * "APFO" means ammonium perfluorooctanoate, and for the purposes of this report includes the anion of the acid perfluorooctanoic acid (PFOA). ASH027185 EXP015750 September 2002 Through August 2003 Air Dispersion Modeling Analysis of APFO Emissions October 17, 20B3 Page3 The Industrial Source Complex Short Term Model (ISCST3) was used as the primary model to estimate long-term pollutant concentrations. ISCST3 is a steady-stallsGaussian model recommended by the U.S. EPA. It is included in the "Guideline on Air QualityModels"^, which is codified as Appendix W to 40 CFR Part 51. It is appropriate for modeling of pollutant emissions from multiple, industrial-type sources subjectto significantbuilding downwash. The downwash algorithms in me ISCST3 model provide a representation oftile aerodynamic downwash of a stack plume caused by complex building configurations typical of industrial facilities. Refined ISCST3 modeling was conducted using one year (1996) of sequential hourly meteorology from die on-site observation facility, as described above. 5. Receptor Selection A Cartesian gridof receptors was utilized in this modeling analysis. This grid consisted of the 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 grid All receptors are located along or outside the plant fenceline. A Cartesian receptor grid of this type is considerably more dense than recommended by the U.S. EPA in the Guidelines on Air Quality Models (U.S. EPA, 1998) for modeling a facility of this type. Terrain elevations for each of me 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. Modeling Procedures The most recent version of ISCST3 (version 02035) was used in the air quality dispersion modeling of all receptors. All model options were set to the U.S. EPA regulatory default version of ISCST3. The model was run in the rural mode since the land area m the immediate vicinity of Washington Works is more than 50% rural. Any effects of aerodynamic downwash caused by structures adjacent to each modeled stack were included in the ISCST3 modeling analysis along with a summary of the building downwash input files (BPIP). Air quality dispersion modeling was conducted on an hour-by-hour basis using the one year of meteorological data described above. The APFO modeling results were summarized for the-annual averaging time period- 7. Results The results of the modeling analysis indicate a maximum predicted annual average APFO concentration of 0.86 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 0.18 ug/m3. This prediction is located at UTM 442600 E, 4347600 N, on the Ohio side of the river. The results are presented graphically in Figure 3. ASH027186 EXP015751 SOOHCB ID September 20B2 Through August 2B03 Air Dispersion Modeling Analysis ofAPFO Emissions October 17,2003 Page4 Table 1 x (MBTERS) y (METERS) *** POIHT somos QAI& *** BASE EI.EV- (feet) Bai.3Sj.oa Rate (Ib/hr) STACK HBisai (feet) STACK TEHP. (DBS.?) STACK BiCtT VSI,. (ft/sec) STACK DIMETER (feet) CEH242 TIM 662 T1E&T1F699 CFS274 R022EEF86 R022EEF89 TIP 644 TH1652 CDB 216 R022EEF6 R022EEF87 THG658 CFK268 C1CA-D205 CDT231 CDW232 TIV697 TIP 694 TIE 647 TIP 648 441954 442025 442091 441787 442069 442063 442084 441920 441960 442086 442058 441923 441774 442310 441953 441952 442129 442104 442125 442109 4346741 4346847 4346836 4346744 4346627 4346635 4346835 4346767 4346788 4346624 4346634 4346756 4346753 4346800 4346766 4346776 4346836 4346822 4346818 4345805 659.4 636.5 639.8 656.2 629.9 629.9 639.8 649.6 659.4 623.4 629.9 649.6 643.0 656.2 659.4 659.4 656.0 656.0 656.0 656.0 6.13E-02 0 0.167 0.1211 0.00045 0.00045 0 0.0034 0 0.00045 0.00045 0.0063 4.00E-03 0 0.2226 0.2255 0.000114 0.000114 0 0 114.5 149.9 170.0 109.9 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 66.0 66.0 230.0 230.0 106.1 40.2 27.9 44.6 40.0 20.0 169.8 54.1 34.5 30.0 10.0 22.4 29.1 84.9 28.4 23.6 152 182 57.0 57.0 0.50 1.33 4.00 0.69 2.00 2.00 1.50 1.96 1.30 2.50 2.00- 1.63 027 0.50 0.67 0.67 1.67 1.87 1.87 1.67 ASH027187 September 2002 Through August 2003 Air Dispersion Modeling Analysis ofAKFO Emissions October 17,2003 PageS Figure 1 Source and Building Locations ASH027188 EXP015753 September 2B02 Tlurou^t August 2003 Air Dispersion Modeling Analysis ofAPFO Emissions October 17,2003 PageS Figured Receptor Grid Used m the Modeling Analysis ASH027189 EXP015754 September 2002 Throag?i August 2003 Air Dispersion Modeling Analysis ofAPFO Emissions October 17,2003 Figure 3 September 2002 - August 2003 APFO Modeled Emissions Annual Average Concentrations (ug/in3) Contour Interval 0.1 ug/m3 ASH027190 EXP015755 September 2002 Through August 2003 Air Dispersion Modeling Analysis ofA?FO Emissions October 17,20W References (1) U. S. EPA, Meteorological Monitoring Qoidance for Regulatory Modeling Applications. EPA4S4/R-99-005, Office of Air QuaBty Planning and Standards, February, 2000. (2) Auer, A. H., "Cocrelation of Land Use Cover with Meteorological Anomalies", Journal of Applied Meteorology, Vol. 17, pp. 636-643,1978. (3) U. S. EPA. Guideline on Air Quality Models (Revised). EPA-450/2-78-027R-C, 2001. ASH027191 EXP015756