1. 1. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants IMPLICATIONS OF ACCURATE SOURCE CHARACTERIZATION ON PERMITTING FOR THE 1-HR AND 24-HR NAAQS Ron Petersen, PhD, CCM CPP, Inc. 1415 Blue Spruce Drive Fort Collins, CO 80525 rpetersen@cppwind.com Cell: 970 690 1344
2. 2. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants Outline What is source characterization? The forgotten but important factor building dimensions Where BPIP inputs are a problems Example applications of AERMOD with better inputs (EBD) Impact of better inputs (i.e., accurate source characterization)
3. 3. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants Source Characterization 2013 EPA Draft SO2 NAAQS Designations Modeling Technical Assistance Document Common considerations Stack height and location, stack parameters, emission rates, in-stack ratios, urban versus rural, etc. Often Overlooked (2 to 8 Reduction in Predicted Design Value) If stack locations and building information are not accurate, downwash will not be accurately accounted for in AERMOD. Building dimension inputs are critical!!!
4. 4. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants Building Dimension Inputs & BPIP BPIP uses building footprints and tier heights Combines buildings All structures become one single rectangular solid for each wind direction and each source BPIP dimensions may not characterize the source and may give the wrong answer. BPIP Input
5. 5. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants AERMODs Building Downwash Algorithm Used EPA wind tunnel data base and past literature Developed analytical equations for cavity height, reattachment, streamline angle, wind speed and turbulence
6. 6. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants AERMODs Building Downwash Algorithm Only valid for certain building sizes W/H 1 to 4 L/H = 0 to 4 Assumes all buildings are solid and rectangular
7. 7. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants Building Dimension Inputs AERMOD Needs to Work The building shape and position that match the theory in AERMOD. BPIP will often not do this. Streamline figures from: Snyder, W.H. and R.E. Lawson, Jr.: Wind Tunnel Measurements of Flow Fields in the Vicinity of Buildings; 8th Joint Conference on Appl. of Air Poll. Met. With A&WMA; AMS, Boston, MA, 1994; pp. 244-250
8. 8. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants Example BPIP Problems PW facility (blue), BPIP building dimensions (red) for stack S-344 (red) and envelope of the building cavity calculated by PRIME (yellow) for a) a wind direction of 90 degrees; and b) a wind direction of 140 degrees. ) BPIP Building Dimensions: H = 17 m L/H = 53 W/H = 34 BPIP Building Dimensions: H = 17 m L/H = 23 W/H = 63 a) b) BPIP Building Dimensions: H = 17 m L/H = 23 W/H = 63 BPIP Input in RED Site Plan and BPIP Result
9. 9. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants Solution - Use EBD in Place of BPIP Dimensions Equivalent Building Dimensions (EBDs) are the dimensions that are input into AERMOD in place of BPIP dimensions to more accurately predict building wake effects Determined using wind tunnel modeling 9
10. 10. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants Current Regulatory Status of EBD October 24, 2011 Model Clearinghouse Review of EBD for AERMOD .. any EBD studies being considered should be discussed with the appropriate reviewing authority as early in the process as possible and that the Model Clearinghouse should also be engaged as early as possible. . these wind tunnel EBD studies are classified as source characterization studies. Roger Brode and George Bridgers, EPA Model Clearinghouse, receptive for those cases where AERMOD with BPIP inputs is not working 2013 EPA R/S/L Modelers Workshop.
11. 11. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants Basic Wind Tunnel Modeling Methodology Obtain source/site data Construct scale model 3D Printing Install model in wind tunnel and measure Cmax versus X
12. 12. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants Measure Ground-level Concentrations Tracer from stack Max ground-level concentrations measured versus x
13. 13. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants Measure Ground-level Concentrations Data taken until good fit and max obtained Automated Max GL Concentration Mapper
14. 14. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants EBD Used to Reduce Predicted AQ Impacts on Residential Tower downwind of Mirant Power Station, Alexandria, VA Residential Tower
15. 15. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants Find EBD that gives same Max GL Concentration Profile as with Site Structures = - Input EBD Into AERMOD for wind directions of concern - AERMOD predicted impacts decreased by more than a factor of two. Mirant Power Station Approved Study, Region 3 Wind Tunnel Testing Conducted with Site Structures and with EBD
16. 16. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants AECOM (David Shea) Conducted Field Study That Validated use of EBD see AWMA 2007 papers
17. 17. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants Example Application Very wide/narrow building Stack height: 47 m Building height: 31 m Property line in Red Emission rate: 1 g/s AERMOD RESULTS Five years of met data
18. 18. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants Maximum Hourly Impact at Fenceline
19. 19. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants BPIP Input Analysis W and L values > 5 times Hb for many wind directions (see red shading) AERMOD will overpredict for these wind directions Past EBD studies and theory show that Lmax and Wmax 4 Hb. New BPIP input generated using this criterion Input filed provided to modeling consultant to re-run AERMOD Flow Wind BUILDHGT BUILDWID BUILDLEN Vector Direction Hb W L XBADJ YBADJ Hb: W: L (Deg.) (Deg.) (m) (m) (m) (m) (m) 0 180 31.09 88.64 304.03 -144.87 -58.28 1.0 2.9 9.8 10 190 24.99 30.53 11.47 -7.79 -18.85 1.0 1.2 0.5 20 200 24.99 30.76 12.48 -4.99 -18.91 1.0 1.2 0.5 30 210 31.09 98.96 301.7 -115.52 -46.9 1.0 3.2 9.7 40 220 31.09 148.5 284.64 -99.38 -40.06 1.0 4.8 9.2 50 230 31.09 193.52 258.94 -80.23 -31.99 1.0 6.2 8.3 60 240 31.09 232.67 225.36 -58.63 -22.96 1.0 7.5 7.2 70 250 31.09 264.74 184.94 -35.26 -13.22 1.0 8.5 5.9 80 260 31.09 288.77 138.9 -10.81 -3.08 1.0 9.3 4.5 90 270 31.09 304.03 88.64 13.97 7.14 1.0 9.8 2.9 100 280 31.09 310.04 35.68 38.32 17.16 1.0 10.0 1.1 110 290 31.09 309.59 46.42 29.12 26.65 1.0 10.0 1.5 120 300 31.09 301.7 98.96 -2.58 35.33 1.0 9.7 3.2 130 310 31.09 284.64 148.5 -34.19 42.94 1.0 9.2 4.8 140 320 31.09 258.94 193.52 -64.77 49.24 1.0 8.3 6.2 150 330 31.09 225.36 232.67 -93.38 54.05 1.0 7.2 7.5 160 340 31.09 184.94 264.74 -119.15 57.21 1.0 5.9 8.5 170 350 31.09 138.9 288.77 -141.3 58.64 1.0 4.5 9.3 180 360 31.09 88.64 304.03 -159.16 58.28 1.0 2.9 9.8 190 10 24.99 30.53 11.47 -3.68 18.85 1.0 1.2 0.5 200 20 24.99 30.76 12.48 -7.49 18.91 1.0 1.2 0.5 210 30 31.09 98.96 301.7 -186.18 46.9 1.0 3.2 9.7 220 40 31.09 148.5 284.64 -185.26 40.06 1.0 4.8 9.2 230 50 31.09 193.52 258.94 -178.71 31.99 1.0 6.2 8.3 240 60 31.09 232.67 225.36 -166.73 22.95 1.0 7.5 7.2 250 70 31.09 264.74 184.94 -149.68 13.22 1.0 8.5 5.9 260 80 31.09 288.77 138.9 -128.09 3.08 1.0 9.3 4.5 270 90 31.09 304.03 88.64 -102.6 -7.14 1.0 9.8 2.9 280 100 31.09 310.04 35.68 -74 -17.16 1.0 10.0 1.1 290 110 31.09 309.59 46.42 -75.54 -26.65 1.0 10.0 1.5 300 120 31.09 301.7 98.96 -96.39 -35.33 1.0 9.7 3.2 310 130 31.09 284.64 148.5 -114.31 -42.94 1.0 9.2 4.8 320 140 31.09 258.94 193.52 -128.75 -49.24 1.0 8.3 6.2 330 150 31.09 225.36 232.67 -139.29 -54.05 1.0 7.2 7.5 340 160 31.09 184.94 264.74 -145.59 -57.21 1.0 5.9 8.5 350 170 31.09 138.9 288.77 -147.47 -58.64 1.0 4.5 9.3 BPIP Dimensions Aspect Ratio
20. 20. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants BPIP Input Analysis Zoom In Flow Wind BUILDHGT BUILDWID BUILDLEN Vector Direction Hb W L XBADJ YBADJ Hb: W: L (Deg.) (Deg.) (m) (m) (m) (m) (m) 0 180 31.09 88.64 304.03 -144.87 -58.28 1.0 2.9 9.8 10 190 24.99 30.53 11.47 -7.79 -18.85 1.0 1.2 0.5 20 200 24.99 30.76 12.48 -4.99 -18.91 1.0 1.2 0.5 30 210 31.09 98.96 301.7 -115.52 -46.9 1.0 3.2 9.7 40 220 31.09 148.5 284.64 -99.38 -40.06 1.0 4.8 9.2 50 230 31.09 193.52 258.94 -80.23 -31.99 1.0 6.2 8.3 60 240 31.09 232.67 225.36 -58.63 -22.96 1.0 7.5 7.2 70 250 31.09 264.74 184.94 -35.26 -13.22 1.0 8.5 5.9 80 260 31.09 288.77 138.9 -10.81 -3.08 1.0 9.3 4.5 90 270 31.09 304.03 88.64 13.97 7.14 1.0 9.8 2.9 100 280 31.09 310.04 35.68 38.32 17.16 1.0 10.0 1.1 110 290 31.09 309.59 46.42 29.12 26.65 1.0 10.0 1.5 120 300 31.09 301.7 98.96 -2.58 35.33 1.0 9.7 3.2 BPIP Dimensions Aspect Ratio
21. 21. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants Estimated EBD values Estimated values to right used to modify AERMOD input file AERMOD re-run with these building dimension inputs AERMOD results below show wind tunnel study likely to help significantly AERMOD Building Dimension Inputs 1-hour 24-hour annual BPIP 15.19 8.20 0.89 Screening EBD Values 9.68 5.05 0.19 AERMOD Maximum predicted concentration (g/m3 ) Flow Wind BUILDHGT BUILDWID BUILDLEN Vector Direction Hb W L XBADJ YBADJ Hb: W: L (Deg.) (Deg.) (m) (m) (m) (m) (m) 0 180 31.09 88.64 124.36 -144.87 -58.28 1.0 2.9 4.0 10 190 24.99 30.53 11.47 -7.79 -18.85 1.0 1.2 0.5 20 200 24.99 30.76 12.48 -4.99 -18.91 1.0 1.2 0.5 30 210 31.09 98.96 124.36 -115.52 -46.9 1.0 3.2 4.0 40 220 31.09 124.36 124.36 -99.38 -40.06 1.0 4.0 4.0 50 230 31.09 124.36 124.36 -80.23 -31.99 1.0 4.0 4.0 60 240 31.09 124.36 124.36 -58.63 -22.96 1.0 4.0 4.0 70 250 31.09 124.36 124.36 -35.26 -13.22 1.0 4.0 4.0 80 260 31.09 124.36 124.36 -10.81 -3.08 1.0 4.0 4.0 90 270 31.09 124.36 88.64 13.97 7.14 1.0 4.0 2.9 100 280 31.09 124.36 35.68 38.32 17.16 1.0 4.0 1.1 110 290 31.09 124.36 46.42 29.12 26.65 1.0 4.0 1.5 120 300 31.09 124.36 98.96 -2.58 35.33 1.0 4.0 3.2 130 310 31.09 124.36 124.36 -34.19 42.94 1.0 4.0 4.0 140 320 31.09 124.36 124.36 -64.77 49.24 1.0 4.0 4.0 150 330 31.09 124.36 124.36 -93.38 54.05 1.0 4.0 4.0 160 340 31.09 124.36 124.36 -119.15 57.21 1.0 4.0 4.0 170 350 31.09 124.36 124.36 -141.3 58.64 1.0 4.0 4.0 180 360 31.09 88.64 124.36 -159.16 58.28 1.0 2.9 4.0 190 10 24.99 30.53 11.47 -3.68 18.85 1.0 1.2 0.5 200 20 24.99 30.76 12.48 -7.49 18.91 1.0 1.2 0.5 210 30 31.09 98.96 124.36 -186.18 46.9 1.0 3.2 4.0 220 40 31.09 124.36 124.36 -185.26 40.06 1.0 4.0 4.0 230 50 31.09 124.36 124.36 -178.71 31.99 1.0 4.0 4.0 240 60 31.09 124.36 124.36 -166.73 22.95 1.0 4.0 4.0 250 70 31.09 124.36 124.36 -149.68 13.22 1.0 4.0 4.0 260 80 31.09 124.36 124.36 -128.09 3.08 1.0 4.0 4.0 270 90 31.09 124.36 88.64 -102.6 -7.14 1.0 4.0 2.9 280 100 31.09 124.36 35.68 -74 -17.16 1.0 4.0 1.1 290 110 31.09 124.36 46.42 -75.54 -26.65 1.0 4.0 1.5 300 120 31.09 124.36 98.96 -96.39 -35.33 1.0 4.0 3.2 310 130 31.09 124.36 124.36 -114.31 -42.94 1.0 4.0 4.0 320 140 31.09 124.36 124.36 -128.75 -49.24 1.0 4.0 4.0 330 150 31.09 124.36 124.36 -139.29 -54.05 1.0 4.0 4.0 340 160 31.09 124.36 124.36 -145.59 -57.21 1.0 4.0 4.0 350 170 31.09 124.36 124.36 -147.47 -58.64 1.0 4.0 4.0 Estimated EBD using Max Width and Length Criteria of 4 times the Height Aspect Ratio
22. 22. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants AERMOD Results With Wind Tunnel EBD Very wide/narrow building Stack height: 47 m Building height: 31 m Property line in Red Emission rate: 1 g/s AERMOD RESULTS Five years of met data AERMOD Building Dimension Inputs 1-hour 24-hour annual BPIP 15.19 8.20 0.89 Wind Tunnel EBD 3.99 1.88 0.18 Reduction Factor 3.80 4.37 4.93 AERMOD Maximum predicted
23. 23. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants Stack at Industrial Facility Stack height = 27 m Q = 1 g/s Building height = 17 m Building width and/or length > 200 m 5 years of meteorological data AERMOD RESULTS SHORT LARGE BUILDING Building Input 1-hr 3-hr 24-hr annual BPIP 129.1 101.7 38.2 4.0 Wind Tunnel EBD 27.3 17.8 7.9 0.5 Reduction Factor 4.7 5.7 4.8 7.9 Maximum concentration (ug/m3 )
24. 24. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants BPIP Max = 38.2 ug/m3 EBD Max = 8.1ug/m3 AERMOD Contours: 24-hr max
25. 25. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants Stack height: 45 m Structure height: 61 m Emission rate: 1 g/s Five years of met data Stack AERMOD Results Lattice Structure Building Input 1-hour 24-hour annual BPIP 23.21 5.51 0.37 Wind Tunnel EBD 7.72 2.36 0.11 Reduction Factor 3.01 2.33 3.51 Maximum Concentration Results
26. 26. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants FACTOR of 4 to 8 reduction when EBD used Short building with a large foot print FACTOR of 2 to 4 reduction when EBD used Hyperbolic cooling towers Typical AERMOD Overprediction Factors When Using BPIP Inputs
27. 27. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants Typical AERMOD Overprediction Factors When Using BPIP Inputs FACTOR of 2 to 5 reduction when EBD used Very Wide/Narrow Buildings FACTOR of 2 to 3.5 reduction when EBD used Lattice Structures
28. 28. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants Result of Accurate Building Dimension Source Characterization More accurate concentration estimates Estimates that are 2 to 8 times lower for appropriate cases Short/wide/long Streamlined Wide Lattice
29. 29. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants Questions? Ron Petersen, Ph.D., CCM CPP, Inc rpetersen@cppwind.com 970 690 1344
30. 30. EUEC 2015, San Diego, CAWind Engineering and Air Quality Consultants EBD Background Several studies conducted and approved using original guidance for ISC applications Amoco Whiting Refinery, Region 5, 1990 Public Service Electric & Gas, Region 2, 1993 Cape Industries, Region 4, 1993 Cambridge Electric Plant, Region 1, 1993 District Energy, Region 5, 1993 Hoechst Celanese Celco Plant, Region 3, 1994 Pleasants Power, Region 3, 2002 Studies conducted using AERMOD Hawaiian Electric (Approved), Region 9, 1998 Mirant Power Station (Approved), Region 3, 2006 Cheswick Power Plant (Approved), Region 3, 2006 Alcoa (Not Approved), Region 7, 2010 Chevron (Approved), Region 4, 2012