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HomeMy WebLinkAboutWPO202100057 Calculations 2021-10-12Pantops Shopping Center Enterprise Car Wash STORMWATER MANAGEMENT CALCULATIONS PACKET Date of Calculations October 6, 2021 PREPARED BY: COLLINS ENG11,1I=ERING 200 GARRETT STREET, SUITE K CHARLOTTESVILLE, VA 22902 434.293.3719 PH 434.293.2813 FX www.collins-engineering.com SCS TR-55 Calculations (Note, all of the areas and land covers listed for the SCS Method stormwater quantity computations differ with the VRRM Method computations for stormwater quality. This is because drainage areas differ from limits of disturbance. Drainage Areas do encompass the entirety of the limits of disturbance) Soils Mapping (Source: NRCS Web Soil Survey Online Database) Soils Table (Source: NRCS Web Soil Survey Online Database) Albemarle County, Virginia (VA003) Albemarle County, Virginia (VA003) 0 Map Unit Percent of Symbol Map Unit Name Act 71C Rabun clay 14.3% loam, 7 to 15 percent slopes 88 Udorthents, 85.7% loamy, 2 to 25 percent slopes Totals for Area of 100.0% Interest Note: The NRCS web soil survey has catorgized this parcel's soil types as having primarily type D soils. As a result, the following calculations take this into consideration. Precipitation Data (Source: NOAA's National Weather Service, Hydrometerorological Design Studies Center, Atlas 14 Point Precipitation Frequency Estimates) e � TertaF // 6 4 I oQ� I I I , Y I I 1 I I 1 I Qa 1 - �WOm Ploe_maL — SOOR ' POINT PRECIPITATION FREQUENCY (PF) ESTIMATES WIT" WA CONFIDENCE INTERVALS AND SUPPLEMENTARY INFORMATION NOAAAIIas 14. Volume 2, Version I PDSbased precipitation frequency estimates with 90% confidence Intervals (in Inches)l AvaaOe recullenca interval (yeas) auane"0+ 00 10 0® 1W 2W ® 1069 2441r (2.T2J;/0) (UW4.12) (4.208-26) (4 5-6.20) (6.04] W) (6: 68.80) p5 --00.1) (9.01a-11.6) 1 (106- 3.0) 1 (118-157) SCS TR-55 Calculations and Pre -Development Hydrographs U.S. Department of Agriculture Natural Resources Conservation Service TR 55 Worksheet 2: Runoff Curve Number and Runoff Project: Enterprise Car Rental Designed By: LMW, PE Location: Pantops Shopping Center Checked By: SRC, PE Check One: Present X Developed 1. Runoff curve Number (CN) FL-ENG-21A 06/04 Date: 10/6/2021 Date: 10/6/2021 Drainage Area Soil name and hydrologic Cover description Area Product of CN CN (weighted) _Calculated'S' (Cover type, treatment, and hydrologic condition; percent ON total product/ Description group (Appendix A) impervious; unconnected/ connected impervious area ratio) (Acres) x Area total area Value ON DAA Impervious Areas 98 0.07 7.3 (Pre-ReDev.) B Woods & Grass Combo in Good Condition 58 0.09 5.2 66 5.13 Lawns in Good Condition (75%+Groundcover) 61 0.33 19.8 Impervious Areas 98 0.32 31.7 ON DAA B Woods & Grass Combo in Good Condition 55 0.00 0.0 85 1.73 (Post-ReDev.) Lawns in Good Condition (75%+Groundcover) 61 0.17 10.4 2. Runoff 1-Year Storm 2-Year Storm 10-Year Storm 100-Year Storm Drainage Area Description Frequency -years 1 2 10 100 n/a Rainfall, P (24 hour)- inches 3.03 3.67 5.54 9.11 n/a Runoff, Q-inches 0.56 0.90 2.11 4.95 ON DA A (Pre-ReDev.) Runoff, Q-inches 1.63 2.19 3.90 7.32 ON DA A (Post-ReDev.) Runoff, Q-inches 3.03 3.67 5.54 9.11 0.0 Runoff, Q-inches 3.03 3.67 5.54 9.11 0.0 Runoff, Q-inches 3.03 3.67 5.54 9.11 0.0 Runoff, Q-inches 3.03 3.67 5.54 9.11 0.0 U.S. Department of Agriculture Natural Resources Conservation Service TR 55 Worksheet 3: Time of Concentration (TJ or Travel Time (Tt) Project: Enterprise Car Rental Location: Pantops Shopping Center Check One: Present X Developed X Check One: Tc X Tt Designed By: UMW, PE Checked By: SRC, PE Through subarea n/a ON DAA ON DAA (Pre-ReDev.) (post - Segment ID: Sheet Flow: (Applicable to T. only) 1 Surface description (Table 3-1) Smooth Surface Smooth Surface 2 Manning's roughness coeff., n (Table 3-1 0.011 0.011 3 Flow length, L (total L < 100) (ft) 13 12 4 Two-year 24-hour rainfall, Pz (in.) 3.7 3.7 5 Land slope, s (ft/ft) 0.02 0.02 6 Compute Tt = [0.007(n•L)o.8] / Pz .5 s.a 0.00 0.00 Shallow Concentrated Flow 7 Surface description (paved or unpaved) Unpaved Paved 8 Flow Length, L (ft) 110 132 9 Watercourse slope, s (ft/ft) 0.080 0.027 10 Average velocity, V (Figure 3-1) (ft/s) 4.5 3.3 11 Tt=L/3600•V 0.01 0.01 Shallow Concentrated Flow: 7 Surface description (paved or unpaved) 8 Flow Length, L (ft) 9 Watercourse slope, s (ft/ft) 30 Average velocity, V (Figure 3-1) (ft/s) 11 Tt=L/3600•V Channel Flow: 12 Cross sectional Flow area, a (ft) 13 Wetted perimeter, P. (ft) 14 Hydraulic radius, r= a/Pw (ft) 15 Channel Slope, s (ft/ft) 16 Manning's Roughness Coeff, n 17 V= [ 1.49r2"so 5]/n 18 Flow length, L (ft) 19 Tt= L / 3600•V 20 Watershed or subarea T. or Tt (Add Tt in steps 6, 11 and 19) 0.00 0.00 0.10 1 0.10 FL-ENG-21A 06/04 Date: 10/6/2021 Date: 10/6/2021 U.S. Department of Agriculture Natural Resources Conservation Service TR 55 Worksheet 4: Graphical Peak Discharge Method Project: Enterprise Car Rental Designed By: LMW, PE Date: 10/6/2021 Location: Pantops Shopping Center Checked By: SRC, PE Date: 10/6/2021 Check One: Present X Developed X 1. Data Drainage Area Description Drainage Area Description ON DAA (Pre-ReDev.( ON DAA (Post-ReDev.) Drainage Area (Am( in miles' 0.0008 0.0008 Runoff curve number CN= 66 85 Time of concentration(Tc)= 0.10 0.10 Rainfall distribution type= II II Pond and swamp areas spread throughout the watershed= 0 0 2. Frequency -years 1 2 10 1 2 10 3. Rainfall, P (24 hour(- inches 3.03 3.67 5.54 3.03 3.67 5.54 4. Initial Abstraction, la -inches 1.03 1.03 1.03 0.35 0.35 0.35 5. Compute la/P D.M 0.28 0.19 0.11 0.09 0.06 6. Unit peak discharge, Qu-am/in Out of Range. See Hydrographs for Flows. Out of Range. See Hydmgraphs for Flows. ]. Runoff, Q from Worksheet 2-inches 0.56 0.90 2.11 1.63 2.19 3.90 8. Pond and Swamp adjustment factor, Fp 1 1 1 1 1 1 9. Peak Discharge, Qp- cts where Qp-Qu Am Q Fp 0." 0.70 1.63 1.26 1.70 3.03 WATERSHED SUMMARY FOR (ONSITE) CHANNEL & FLOOD PROTECTION ANALYSIS CN Area, ac. 1-year Flow, cfs 2-year Flow, cfs 10-year Flow, cfs ON DAA(Pre-ReDev.) ON DA A+B(Post-ReDev.) i 66 0.49 0." 0.70 1.63 85 0.49 0.14 0.69 1.61 1-yr. 24-hr. SCS TR-55 Method Unit Hydrograph for the la/P & Tc Listed Below Subarea Tc (hrs.) Tt (hr.) la / P Am*Q (mi2-in) ONDAA 0.10 0.10 0.34 0.0004 (Pre-ReDev.) Hydrograph Time (hrs.) 1-yr Discharges (cfs) 0.0 0.00 11.0 0.01 11.3 0.01 11.6 0.02 11.9 0.14 12.0 0.28 12.1 0.44 12.2 0.27 12.3 0.09 12.4 0.06 12.5 0.05 12.6 0.04 12.7 0.04 12.8 0.03 13.0 0.03 13.2 0.02 13.4 0.02 13.6 0.02 13.8 0.02 14.0 0.02 14.3 0.01 14.6 0.01 15.0 0.01 15.5 0.01 16.0 0.01 16.5 0.01 17.0 0.01 17.5 0.01 18.0 0.01 19.0 0.01 20.0 0.01 22.0 0.01 26.0 0.00 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 0.0 SCS TR-55 Pre-ReDevelopment Unit Hydrograph (ON DA A) 5.0 10.0 15.0 20.0 25.0 30.0 Worksheet 5b (Modified for Clarity): Basic watershed Data 2-yr. 24-hr. SCS TR-55 Method Unit Hydrograph for the la/P & Tc Listed Below Subarea Tc (hrs.) Tt (hr.) la / P Am*Q (mi2-in) ONDAA 0.10 0.10 0.28 0.0007 (Pre-ReDev.) Hydrograph Time (hrs.) 2-yr Discharges (cfs) 0.0 0.00 11.0 0.02 11.3 0.02 11.6 0.04 11.9 0.23 12.0 0.45 12.1 0.70 12.2 0.43 12.3 0.15 12.4 0.10 12.5 0.08 12.6 0.07 12.7 0.06 12.8 0.05 13.0 0.05 13.2 0.04 13.4 0.04 13.6 0.03 13.8 0.03 14.0 0.03 14.3 0.02 14.6 0.02 15.0 0.02 15.5 0.02 16.0 0.02 16.5 0.01 17.0 0.01 17.5 0.01 18.0 0.01 19.0 0.01 20.0 0.01 22.0 0.01 26.0 0.00 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0.00 SCS TR-55 Pre-ReDevelopment Unit Hydrograph (ON DA A) 0.0 5.0 10.0 15.0 20.0 25.0 30.0 Worksheet 5b (Modified for Clarity): Basic watershed Data 10-yr. 24-hr. SCS TR-55 Method Unit Hydrograph for the la/P & Tc Listed Below Subarea Tc (hrs.) Tt (hr.) la / P Am•Q (mil -in) ONDAA 0.10 0.10 0.19 0.0016 (Pre-ReDev.) Hydrograph Time (hrs.) 10-yr Discharges (cfs) 0.0 0.00 11.0 0.04 11.3 0.06 11.6 0.09 11.9 0.54 12.0 1.05 12.1 1.63 12.2 1.01 12.3 0.35 12.4 0.24 12.5 0.20 12.6 0.17 12.7 0.14 12.8 0.12 13.0 0.11 13.2 0.09 13.4 0.08 13.6 0.07 13.8 0.07 14.0 0.06 14.3 0.06 14.6 0.05 15.0 0.05 15.5 0.04 16.0 0.04 16.5 0.03 17.0 0.03 17.5 0.03 18.0 0.03 19.0 0.02 20.0 0.02 22.0 0.02 26.0 0.00 1.80 1.60 1.40 1.20 1.00 0.80 0.60 0.40 0.20 0.00 c SCS TR-55 Pre-ReDevelopment Unit Hydrograph (ON DA A) Post -Development Site Hydrographs and Proposed Underground Detention System Analysis (The following routing calculations and outflow hydrographs reflect the post - development attenuation in Subarea A from the proposed underground detention facility) Post -Development DA A (From Underground Detention Routings) Hydrograph Time (hrs.) 1-yr Discharges (cfs) 0.0 0.00 11.0 0.06 11.3 0.08 11.6 0.18 11.9 1.00 12.0 0.80 12.1 0.27 12.2 0.14 12.3 0.12 12.4 0.10 12.5 0.08 12.6 0.07 12.7 0.06 12.8 0.06 13.0 0.05 13.2 0.05 13.4 0.04 13.6 0.04 13.8 0.03 14.0 0.03 14.3 0.03 14.6 0.03 15.0 0.02 15.5 0.02 16.0 0.02 16.5 0.02 17.0 0.02 17.5 0.02 18.0 0.01 19.0 0.01 20.0 0.01 22.0 0.01 26.0 0.00 1.20 1.00 0.80 0.60 0.40 0.20 0.00 Inflow Hydrograph (ON DA A) 0.0 5.0 10.0 15.0 20.0 25.0 30.0 Post -Development DA A (From Underground Detention Routings) Hydrograph Time (hrs.) 2-yr Discharges (cfs) 0.0 0.00 11.0 0.07 11.3 0.10 11.6 0.24 11.9 1.34 12.0 1.07 12.1 0.36 12.2 0.19 12.3 0.16 12.4 0.14 12.5 0.11 12.6 0.09 12.7 0.09 12.8 0.08 13.0 0.07 13.2 0.06 13.4 0.06 13.6 0.05 13.8 0.05 14.0 0.04 14.3 0.04 14.6 0.04 15.0 0.03 15.5 0.03 16.0 0.03 16.5 0.02 17.0 0.02 17.5 0.02 18.0 0.02 19.0 0.02 20.0 0.01 22.0 0.01 26.0 0.00 1.60 1.40 1.20 1.00 0.80 0.60 0.40 0.20 0.00 Inflow Hydrograph (ON DA A) 0.0 5.0 10.0 15.0 20.0 25.0 30.0 Post -Development DA A (From Underground Detention Routings) Hydrograph Time (hrs.) 10-yr Discharges (cfs) 0.0 0.00 11.0 0.13 11.3 0.18 11.6 0.42 11.9 2.40 12.0 1.92 12.1 0.64 12.2 0.35 12.3 0.28 12.4 0.24 12.5 0.20 12.6 0.17 12.7 0.15 12.8 0.14 13.0 0.12 13.2 0.11 13.4 0.10 13.6 0.09 13.8 0.08 14.0 0.07 14.3 0.07 14.6 0.06 15.0 0.06 15.5 0.05 16.0 0.04 16.5 0.04 17.0 0.04 17.5 0.04 18.0 0.04 19.0 0.03 20.0 0.03 22.0 0.02 26.0 0.00 3.00 2.50 2.00 1.50 1.00 0.50 0.00 Inflow Hydrograph (ON DA A) 0.0 5.0 10.0 15.0 20.0 25.0 30.0 BasinFlow printout INPUT: Basin: Enterprise Car Wash UGD 0 Contour Areas Elevation(ft) Area(sf) Computed Vol.(cy) 2 Storage Pipes Storage pipe 0 name: Detention Pipe diameter (in) 48.000 length (ft) 80.000 invert (ft) 344.000 angle 0.287 volume (cy) 37.234 Storage pipe 1 name: name diameter (in) 48.000 length (ft) 80.000 invert (ft) 344.000 angle 0.287 volume (cy) 37.234 Start—Elevation(ft) 5 Outlet Structures Outlet structure 0 Orifice 344.00 Vol.(cy) 0.00 name: Barrel area (sf) 1.227 diameter or depth (in) 15.000 width for rect. (in) 0.000 coefficient 0.600 invert (ft) 343.900 multiple 1 discharge out of riser Outlet structure 1 Orifice name: Low -Flow Orifice area (sf) 0.009 diameter or depth (in) 1.250 width for rect. (in) 0.000 coefficient 0.600 invert (ft) 344.000 multiple 2 discharge into riser Outlet structure 2 Orifice name: Mid -Flow Orifice area (sf) 0.292 diameter or depth (in) 6.000 width for rect. (in) 7.000 coefficient 0.600 invert (ft) 346.200 multiple 1 discharge into riser Outlet structure 3 Orifice name: Overflow Weir area (sf) 0.906 diameter or depth (in) 12.890 width for rect. (in) 0.000 coefficient 0.600 invert (ft) 347.500 multiple 1 discharge into riser Outlet structure 4 Orifice name: Emergency Bypass area (sf) 0.785 diameter or depth (in) 12.000 width for rect. (in) 0.000 coefficient 0.600 invert (ft) 347.000 multiple 1 discharge out of riser 3 Inflow Hydrographs Hydrograph 0 SCS name: 1-yr 24-hr SCS TR-55 Design Storm Area (acres) 0.490 CN 85.000 Type 2 rainfall, P (in) 3.030 time of conc. (hrs) 0.1000 time increment (hrs) 0.0200 time limit (hrs) 30.000 fudge factor 1.00 routed true peak flow (cfs) 1.003 peak time (hrs) 11.917 volume (cy) 106.205 Hydrograph 1 SCS name: Area (acres) CN Type rainfall, P (in) time of conc. (hrs) time increment (hrs) time limit (hrs) fudge factor routed peak flow (cfs) peak time (hrs) volume (cy) Hydrograph 2 SCS name: Area (acres) CN Type rainfall, P (in) time of conc. (hrs) time increment (hrs) time limit (hrs) fudge factor routed peak flow (cfs) peak time (hrs) volume (cy) OUTPUT: 2-yr 24-hr SCS 0.490 85.000 2 3.670 0.1000 0.0200 30.000 1.00 true 1.346 11.917 142.526 10-yr 24-hr SCS 0.490 85.000 2 5.540 0.1000 0.0200 30.000 1.00 true 2.406 11.917 254.770 Routing Method: storage -indication Hydrograph 0 Routing Summary of inflow (cfs) discharge (cfs) water level (ft) storage (cy) Hydrograph 1 Routing Summary of inflow (cfs) discharge (cfs) water level (ft) storage (cy) TR-55 Design Storm TR-55 Design Storm Peaks: 1-yr 24-hr SCS TR-55 Design Storm 0.998 at 11.92 (hrs) 0.140 at 12.18 (hrs) 346.248 at 12.20 (hrs) 38.355 Peaks: 2-yr 24-hr SCS TR-55 Design Storm 1.340 at 11.92 (hrs) 0.691 at 12.06 (hrs) 346.609 at 12.06 (hrs) 46.830 Hydrograph 2 Routing Summary of Peaks: 10-yr 24-hr SCS TR-55 Design Storm inflow (cfs) 2.395 at 11.92 (hrs) discharge (cfs) 1.605 at 12.02 (hrs) water level (ft) 347.518 at 12.02 (hrs) storage (cy) 65.956 Wed Oct 06 12:58:48 EDT 2021 Channel and Flood Protection Compliance 9 VAC 25-870-66 Section B: Channel Protection Utilizing a 1-inch Orifice "Concentrated stormwater flow shall be released into a stormwater conveyance system and shall meet the criteria in subdivision 1, 2 or 3 of this subsection..." Section BA: Manmade stormwater conveyance systems "When stormwater from a development is discharged to a manmade stormwater conveyance system, following the land - disturbing activity, either..." a. or b. shall be met: Section B.1.b. "The peak discharge requirements for concentrated stormwater flow to natural stormwater conveyance systems in subdivision 3 of this subsection shall be met." Section B.3 "... the maximum peak flow rate from the one-year 24-hour storm following the land -disturbing activity shall be calculated either.." a. or b." Section B.3.a. In accordance with the following methodology: Q Allowed < I.F. • (Q Pre -Developed * (RV pre -Developed) ) / (RV Developed ) Q Allowed < 0.14 cfs Where: QPre-Develop 0.44 cfs CN Pre-Develo 66 S Pre -Develop. 5.13 RV Pre-Deveio 0.56 in. A Pre -Develop¢ 0.49 ac. CN P,Devee 85 S po:t-Deeiop. 1.76 RV Post-Deve„ 1.61 in. A Developed = 0.49 ae. I.F. = 0.90 Q Developed = 0.14 cfs Section B.4 Limits of Analysis (From TR-55) (From Curve Number Summary) (From SCS TR-55 eq. 2-4) (From SCS TR-55 eq. 2-3) (From Worksheet4 Watershed Summary) (From Curve Number Summary) (From SCS TR-55 eq. 2-4) (From SCS TR-55 eq. 2-3) (From Worksheet4 Watershed Summary) (Factor of Safety) The analysis terminates at Post -Development Subarea A since subsection B.3.a is met. 9 VAC 25-870-66 Onsite Site Outfall #1 Section C: Flood Protection "Concentrated stormwater flow shall be released into a stormwater conveyance system and shall meet one of the following criteria as demonstrated by use of acceptable hydrologic and hydraulic methodologies:" Section C.2.b.: The point of discharge "releases a postdevelopment peak flow rate for the 10-year 24-hour storm event that is less than the predevelopment peak flow rate from the 10-year 24-hour storm event. Downstream stormwater conveyance systems do not require any additional analysis to show compliance with flood protection criteria if this option is utilized." Pre -Development Onsite DA A 10-yr SCS 24-hr Peak Flow (cfs) = 1.63 Post -Development Onsite DA A 10-yr SCS 24-hr Peak Flow (cfs) = 1.61 Section C.3 Limits of Analysis The analysis terminates at the Subarea A since subsection C.2.b is met. DEQ Virginia Runoff Reduction Method Water Quality Calculations (COMPLIANCE IS MET THROUGH THE BEST MANAGEMENT PRACTICES OF PURCHASING NUTRIENT CREDITS. PLEASE NOTE, THE AREAS SHOWN IN THE VRRM SPREADSHEET ARE DIFFERENT TO THOSE AREAS SHOWN IN THE SCS METHOD CALCULATIONS FOR STORMWATER QUANTITY.) mr, a-, d.od Re-.eme., andamue�pmadomm, - 0 20� Enaft EHMP Stddladd-d Sgamnamon, Projea N-: treumm. .1 .�Io - .., �Ioo,dd, ed. ld"eodi Imear Ded�10,dnv,m PMJ� No Site Information _ Post-Demelopment Project (Treatment Volume and I-oads) Eme, Tmal Di,lu,bad �a. Cha�k un-onv"? No ae.-Imuna. Landeovar Aeol, .�Ik C�11, Deol, �-D-eb;dnena laudd Onnu JaCred Auoll 'V--- .n.n. du... C...deno, (a�) A- .-. 1-1 Cumn, I- a- �d a- I.a XTEMPM—MAMITWOMM S -7-P, . an -u-d .1-1 � an de 023 020 % M­d 11 �2 TIMISMI �Coao -P ona de de .13 ead N.dTuI and M­d- 3ee .11 ell " a :.3, M—A %I-W- me F.-'-- W-1 Oad a.. Tramerwout Volume and Natrona Load TreatMent Volume and NUIrent LOad — u-n—d— ..133 T- V" .32� -t I'll, P.1 D-p-nt -.1 .... . ... .1 el, F F-.. P-t D-­W X. p ­-.7. nI V.1 IV t, L Laul de_,.� .... � d,ed (wo) llh* d", P­ 111d -"ou* d,.I.d lwu== Poet -Development Requirement ftr She Area Site Results (Water Quality Compliance) Area Checks D.A. A D.A. B D.A. C D.A. D D.A. E AREA CHECK FOREST/OPEN SPACE (ac) 0.00 0.00 0.00 0.00 0.00 OK. IMPERVIOUS COVER (ac) 0.00 0.00 0.00 0.00 0.00 OK. IMPERVIOUS COVER TREATED [ac) 0.00 0.00 0.00 0.00 0.00 OK. MANAGED TURF AREA (ac) 0.00 0.00 0.00 0.00 0.00 OK. MANAGED TURF AREA TREATED (ac) 0.00 0.00 0.00 0.00 0.00 OK. AREA CHECK Site Treatment Volume (ft3) T,aoB Runoff Reduction Volume and TP By Drainage Area RUNOFF REDUCTION VOLUME ACHIEVED (fe)l 0 0 0 0 0 0 TP LOAD AVAILABLE FOR REMOVAL (Ib/yr) D.00 0.00 0.00 0.00 0.00 0.00 TP LOAD REDUCTION ACHIEVED (Ib/yr) D.00 0.00 0.00 0.00 0.00 0.00 TP LOAD REMAINING (Ib/yr) 0.00 0.00 0.00 0.00 11 0.00 0.00 NITROGEN LOAD REDUCTION ACHIEVED (Ib/yr) 0.00 0.00 0.00 0.00 0.00 0.00 Total Phosphorus FINAL POST -DEVELOPMENT TP LOAD(Ib/yr) 1 0.88 TP LOAD REDUCTION REQUIRED (Ib/yr) 0.46 TP LOAD REDUCTION ACHIEVED (Ib/yr) 0.00 TP LOAD REMAINING (Ib/yr): 0.88 REMAINING TP LOAD REDUCTION REQUIRED (Ib/yr): 0.46