Document B5aB1pOwR9Q45KJp0Jxw4EBQX

AR226-2652 42 AR226-2652 SEPTEMBER 2002 THROUGH AUGUST 2003 AIR DISPERSION MODELING ANALYSIS OF APFO EMISSIONS DuPont Washington Works Facility Parkersburg, 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 Wilmmgton,DE 19898 October 17,2003 1. Introduction September 2002 Through August 2003 Air Dispersion Modeling Analysis of APFO Emissions October 17,2003 Page 2 of 8 DuPont conducted air dispersion modeling of APFO* emissions from its Washington Works facility located near Parkersburg, WV. Modeling was conducted to predict long-term ambient air concentrations of APFO resulting from actual plant emissions that occurred during the period of September, 2002 through August, 2003. This report describes the APFO emissions inventory used in the modeling analysis, the meteorological data, the dispersion model and modeling procedures, prediction locations (receptor grid), and the 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 the stack parameters are presented in Table 1, which shows the source representation for modeling purposes. The estimated actual emission rates of APFO, per source, are also presented in Table 1. Figure 1 presents the general locations of the APFO sources. 3. Meteorological Data One year ofon-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 m/s were treated consistent with the recommendations made in the EPA's "Meteorological Monitoring Guidance for Regulatory Modeling Applications (1). 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 this 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). C:\c8\c8_0803_report ' 2 September 2002 Through August 2003 Air Dispersion Modeling Analysis of APFO Emissions October 17, 2003 Page 3 of 8 The Industrial Source Complex Short Term 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", which is codified as Appendix W to 40 CFR Part 51. It is appropriate for modeling of pollutant emissions from multiple, industrial-type sources subject to significant building downwash. The downwash algorithms in the ISCST3 model provide a representation of the 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 the on-site observation facility, as described above. 5. Receptor Selection A Cartesian grid of 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 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. 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 in 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 (BPEP). 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. C:\c8\c8_0803_report 3 SOURCE ID September 2002 Through August 2003 Air Dispersion Modeling Analysis ofAPFO Emissions October 17,2003 Page 4 of 8 Table 1 x (METERS) Y (METERS) *** POINT SOURCE DATA *** BASE ELEV. (feet) Emission Rate (Ib/hr) STACK HEIGHT (feet) STACK TEMP. (DEG.F) STACK EXIT VEL. (ft/sec) STACK DIAMETER (feet) (IBBBB TIMi62' CFS'274 R022EEF86 R022EEF89 TIF 644 cbB'iTe R022EEF6 R022EEF87 cn<i&8 C1CA-D205 TIV 697 TIF 694 TIE 647 TIF 648 ----1 ---- 442025 4346847 44^7g7 442069 442063 442084 4346744 4346627 4346635 4346835 441960 442086 442058 4346788 4346624 4346634 441774 442310 441974 441953 442129 442104 442125 442109 4346753 4346800 4346772 4346766 4346836 4346822 4346818 4346805 visa iMaasis 63"6l5 .^^ ,.^ 656.2 629.9 629.9 639.8 659.4 623.4 629.9 0"1211 0.00045 0.00045 0 '0 0.00045 0.00045 64'3lo 4.00E-03 656.2 0 656TM0 0.000114 656.0 0.000114 656.0 0 656.0 0 ---- 149.9 logs 48.9 48.9 59.1 60.0 46.9 48.9 63 72.5 6.7 92 99 45.0 45.0 69.0 69.0 SB 172.0 254.9 80.0 80.0 110.9 ^g;;,' 80.0 80.0 Ti'ao 70.0 "66.0 66.0 230.0 230.0 89:0 40.2 27,9 44.6 40.0 20.0 169.8 150 34.5 30.0 10.0 66 29.1 84.9 24.4 33.9 15.2 15.2 57.0 57.0 mi r.33 0.69 2.00 2.00 1.50 0.83 1.30 2.50 2.00 1.50 0.27 0.50 T.67 1.67 1.67 1.67 C:\c8\c8_0803_report September 2002 Through August 2003 Air Dispersion Modeling Analysis of APFO Emissions October 17,2003 Page 5 of 8 Figure 1 Source and Building Locations C:\c8\c8_0803_report 4349000 September 2002 Through August 2003 Air Dispersion Modeling Analysis of APFO Emissions October 17,2003 Page 6 of 8 Figure 2 Receptor Grid Used in the Modeling Analysis 43480004++* .4347000 43460004 4345000 C:\c8\c8_0803_repon September 2002 Through August 2003 Air Dispersion Modeling Analysis of APPO Emissions October 17,2003 Page 7 of 8 Figure 3 September 2002 - August 2003 APFO Modeled Emissions Annual Average Concentrations (ug/m ) Contour Interval 0.1 ug/m3 C:\c8\c8_0803_report September 2002 Through August 2003 Air Dispersion Modeling Analysis of APFO Emissions October 17,2003 Page 8 of 8 References (1) U. S. EPA, Meteorological Monitoring Guidance for Regulatory Modeling Applications, EPA454/R-99-005, Office of Air Quality Planning and Standards, February, 2000. (2) Auer, A. H., "Correlation 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. C:\c8\c8_0803_repon -