Document a1aB4kN480QnNr1q40ppEoq2e

AR226-2361 September 2002 Through August 2003 Air Dispersion Modeling Analysis ofAPFO Emissions (Revised) May 24,2004 Page 1 of 9 SEPTEMBER 2002 THROUGH AUGUST 2003 AIR DISPERSION MODELING ANALYSIS OF APFO EMISSIONS .- _..-_ -_... -..--_^-_ __.---__--.-.. (Revised)- --- - - - -------------- - -... - - -- DuPont Washington Works Facility Parkersburg, West Virginia Prepared for: West Virginia Department of Environmental Protection Division of Air Quality 7012 MacCorkIe Ave, SE Charleston, WV 25304-2943 Prepared by: DuPont Engineering Technology (DuET) Environmental Section Wunrington,DE 19898 C:\c8\c8_0803_report_Kvistd May 24,2004 ( EID775177 EID775177 September 2002 Through August 2003 Air Dispersion Modeling Analysis ofAPFO Emissions (Revised) May 24,2004 Page 2 of 9 1. Introduction DuPont conducted ait dispersion modeling ofAPFO* emissions from its WasmngtonWbrks facility "tocatecTiiearParEersBurg,WV7Mbdelmg^ascohdiictedtopreairt^ concentrations ofAPFO resulting ftotn actual plant emissions that occulted duritig the period of September, 2002 throughAugust, 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. Compared to the modeling report submitted on October 17,2003, this revised report incorporates several revisions to stack parameters that were the result of stack testing, and the refinement ofUTM coordinates. 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 ofAPFO, 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 EID775178 * "APFO" means ammonium perfluorooctanoate, and for the purposes of this report includes the anion of the acid periluorooctanoic acid (PFOA). C:te8\c8_0803_n:poit_reviseil 2 EID775178 Model Selection September 2002 Through August 2003 Air Dispersion Modeling Analysis ofAPFO Emissions (Revised) May 24,2004 Page 3 of 9 The area stittoundmgWashingtonWorks is primarilynon-urban. The U. S. EPA proceduresclassify land use within 3 kilometers of the site by the Auer method^. Previous review ofU. S. GeologicalSurvey (USGS) maps, aerial photographs, and site visits clearlyindicated that the area is well over 50% non-ittbafc-^^WashiH^eaWorksAeili^^lecated^widm^Ae^Bio-Kvet-valle^^ significant terrain features on both sides of this river valley. As a result, terrain elevations were considered in the modeling analysis. 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 Models110^which is codified as Appendix W to 40 CFR Part 51. It is appropriatefor modeling of pollutant emissions from multiple, industrial-type sources subjectto significantbuilding downwash. The downwash algorithms in me 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 fiom 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 arc 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 (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. C:\c8\c8_0803_repon_reviscd EID775179 EID775179 7. Results September 2002 Through August 2003 Air Dispersion Modeling Analysis ofAfFO Emissions (Revised) May 24,2004 Page 4 of 9 The results of file Modelinganalysisindicate a maxifliuffl predictedannual average APPO concentration of 0.70 Ug/m3. This maxittttflU is located alongthe northern properly fenceline, along the Ohio River, at tjTM 442043 fi, 4346883 N. The tnaxiaititn predictedAPPO concentrarion m an area where people may ieside-is O.irtlgft^^-TtfeptedictiottiylocatedattJiM 44266&S, 4M760^N,TOrthereiio siderofthe-- river. The tesults ate presentedgraphicallym Figure 3. C:Vc8\c8_0803_teportjrevised 4 EID775T80 EID775180 Vent ID 699 697 694 658 652 231 232 242 274 268 276 September 2002 Through August 2003 Air Dispersion Modeling Analysis of APfO Emissions (Revised) May 24,2004 Page 5 of 9 Table 1 *** POtlitt SOOECS DATA *** UTM-E 442098 442128 442101 441928 441926 441953 441952 441945 441787 441774 441842 UTM-N 4346843 4346829 4346815 4346757 4346758 4346766 4346776 4346746 4346744 4346753 4346772 Stack Diameter ft 4 2.25 1.67 1.5 0.88 0.67 0.67 0.5 0.65 0.27 1.5 Stack Height ft 170 45 45 63 64 92 99 114.5 110- 72-5 75 Stack Flow Stack Velocity ACFM 12,000 2,000 344 6,478 4,031 510 710 1,048 718 100 5,000 ft/sec 15.9 8.4 2.6 61.1 111.7 24.4 33.9 89.0 36.6 28.7 47.2 Stack Tettip F 124 176 112 142 139 148 128 117 163 110 amb Acfuar C8 Emissions Ib/yr 1,463 0.7 1.0 55 30 1,950 1,975 537 860 35 0.16 'AcluarC8 Emissions Ib/hr 0.1670 0.0001 0.0001 0.0063 0.0034 0.2227 0.2254 0.0613 0.0982 0.0040 0.000018 R022EEF6 442086 4346624 2.5 R022EEF86 442069 4346627 2 R022EEF87 442058 4346634 2 R022EEF89 442063 4346635 2 47 8836 49 7540 49 1885 49 3770 80 12 80 0.3 80 3 80 0.6 0.00045 0.0004S 0.00045 0.00045 C:\c&\c8_0803_report_reviscd E1D775181 EID775181 September 2002 through August 2003 Air Dispersion Modeling Analysis ofAPFO Emissions (Revised) May 24,2004 1fage6<rf9 Figure 1 SQttreeattd.BttSldingLocatiotts C:\c8\c8_0803_repDrt_revlscd EID775182 EID775182 4349000 September 2002 Through August 2003 Air Dispersion Modeling Analysis ofAJPTO Emissions (Revised) May 24,2004 Pagt7of9 Figure 2 Receptor Grid Used in the Modeling Analysis 43480004 43470004 + 43460004 43450004 C:\c8\c8_0803_ieport_revised EID775183 EID775183 September 2002 Through August 2003 Air Dispersion Modeling Analysis of APFO Emissiotts (Revised) May 24,2004 Page 8 of 9 Figure 3 - ~SeptetriBeF2002T- AugBsf 2003 APF& ModetedEmission^ -- Annual Average Concentrations (ug/m3) Contour Interval 0.1 ug/m3 E1D775184 C:te8\c8_OB03_report_rCTiscd E1D775184 September 2002 Through August 2003 Air Dispersion Modeling Aaalysis oiA?lFO Emissions (Revised) May 24,2004 References ---- - - " - - (1) V; SrI^A, MeteotologicalMotlitotilieLdtmtettce for RegulatoryModeKn^Apptications.EPA- 454/R-99-005, Office of Air Quality Planning and Standards, Februaty, 2000. ~" (2) Auer, A. H., "Cotrelatfon of Land Use Coves 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_repott_reiscd 9 EID775185 EID775185