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Bongards - Stormwater Mgmt Report for Proof of Parking plans_ to City + RPBCWD_06-30-17 I hereby certify that this report was prepared by me or under my direct supervision and that I am a registered engineer under the laws of the state of Minnesota. Signature: _______________________ License No:___47514________ Steven Gebauer, PE Bongards Redevelopment – Proof of Parking Stormwater Management Plan & Report Prepared by: Solution Blue, Inc. Date: 06/30/17 Prepared for: City of Chanhassen & Riley Purgatory Bluff Creek Watershed District 06/30/201 7 BONGARDS EXPANSION : STORMWATER MANAGEM ENT PLAN 1 CONTENTS Background ........................................................................................................................................................... 2 Stormwater Management Plan .............................................................................................................................. 2 Existing Condition Calculations .............................................................................................................................. 2 Proof of Parking Condition Calculations ................................................................................................................. 3 Water Quality Treatment ....................................................................................................................................... 3 Conclusion ............................................................................................................................................................. 4 APPENDIX A: Drainage Area Maps ........................................................................................................................A APPENDIX B: HydroCAD Model ............................................................................................................................. B APPENDIX C: Geotechnical Report ........................................................................................................................ C APPENDIX D: P8 Model Results ............................................................................................................................ D 06 /30/2017 BONGARDS EXPANSION: STORMWATER MANAGEMEN T PLAN 2 BACKGROUND The proposed Bongards building and parking lot expansion is located within the City of Chanhassen and the Riley Purgatory Bluff Creek Watershed District (RPBCWD). The site must meet the following stormwater requirements of the RPBCWD: Application: For the redevelopment, the proposed activity disturbs less than 50% of the existing impervious surface and does not increase the imperviousness of the entire parcel by more than 50%. Therefore, the stormwater criteria for RPBCWD only applies to the disturbed areas and additional impervious surface on the project parcel. Rate control: Limit peak runoff rates to that from existing conditions for the 2-, 10-, and 100-yr frequency storm events using a nested 24-hr rainfall distribution, and a 100-yr frequency, 10-day snowmelt event, for all points where stormwater discharge leaves the site. Volume control/Water Quality: Provide the abstraction onsite of 1.1 inches of runoff from impervious surface of the parcel. Pre-treatment must be provided for infiltration and filtration basins, and the bottom of infiltration facilities must be at least three feet above the seasonal high water table. STORMWATER MANAGEMEN T PLAN The following document is intended to explain the existing and proposed stormwater management for a building and parking lot expansion off of Commerce Drive in Chanhassen, MN. The total site area is 1.81 ac (78,666 SF). For the proposed proof of parking conditions, the total impervious increases from 0.64 ac (27,950 SF) to 0.96 ac (41,878 SF). Out of the total site, only 0.61 ac (26,464 SF) are disturbed, with only 0.04 ac (1,527 SF) of disturbed existing impervious. Existing site conditions include an existing parking lot and building. The majority of the site’s runoff drains south towards and existing catch basin and the city’s stormwater sewer system. A portion of the site, mostly pervious, drains north. Proposed proof of parking site improvements include adding a building expansion and parking lot expansion with the addition of pervious pavers. Proposed BMPs include underground rock/pipe storage infiltration/filtration basin. This BMP has been designed to be in compliance with the City of Chanhassen and RPBCWD stormwater requirements listed in the Background section. We analyzed the existing and preliminary proposed site hydrology using HydroCAD. To estimate existing and proposed runoff rates, runoff volume, and water quality, we performed hydrology modeling for the existing and proposed site. We divided the site into drainage boundaries, input land use, soils information, pond storage, and precipitation depths corresponding to the required design storms. EXISTING CONDITION C AL CULATIONS The existing disturbed site area contains 1.16 ac (50,716 SF) of grassed pervious area and 0.64 ac (27,950 SF) of existing parking lot and building impervious, out of a total area 1.81 ac (78,666 SF), or 35.5% impervious. Drainage Area maps are included in Appendix A. EXISTING RUNOFF RATE The existing site does not contain any impervious surface or existing stormwater BMPs on-site. HydroCAD models were used to determine peak runoff rates for the existing site and the existing site with off-site drainage. Drainage 06 /30/2017 BONGARDS EXPANSION: STORMWATER MANAGEMEN T PLAN 3 leaves the site at 3 locations: overland drainage north, overland drainage south, and collection by an existing storm sewer system that eventually leaves the site to the northwest and drains to a regional stormwater pond. Table 1 Runoff calculations for the MSE-3, 24-hr events for the 2-yr, 10-yr, and 100-yr events for Total Site 1 See Appendix A HydroCAD report: Existing PROOF OF PARKING CONDITION CALCULATIO NS Proposed site improvements include adding a building expansion and parking lot expansion with addition of pervious pavers. The proposed disturbed site contains 0.96 ac (41,878 SF) of impervious out of a total area of 1.81 ac (78,666 SF), or 53.2% impervious. Drainage Area maps are included in Appendix A. PRO OF OF PARKING RUNOFF RATE Without stormwater management BMPs, the proposed site would have runoff rates exceeding the existing site peak runoff for the 2-yr, 10-yr, and 100-yr rainfall events. To provide sufficient peak flow retention for the 2-year, 10-year, and 100-year storm events, an underground rock storage filtration/infiltration basin is proposed beneathe parking lot area. Table 2 Existing and Proposed peak runoff rates for the 2-yr, 10-yr, and 100-yr rainfall events 1 See Appendix B HydroCAD report: Existing. 2 See Appendix B HydroCAD report: Proposed. WATER QUALITY TREATM ENT The Riley Purgatory Bluff Creek Watershed District (RPBCWD) requires 1.1 inches of runoff over new impervious to be infiltrated on-site. The proof of parking conditions requires an infiltration volume of 1,417 CF (15,455 SF added and disturbed existing impervious x 1.1 inches x 1 ft/12 inches). According to the Geotechnical Report, the majority of the soils on-site are sandy lean clay (CL), which corresponds to HSG D and an infiltration rate of 0.06 Rainfall Event Existing- North(cfs)1 Existing – South(cfs)1 Existing- Northwest(cfs)1 Existing-Total (cfs)1 2-yr 24 hour 1.7 0.6 3.4 5.6 10-yr 24 hour 3.5 1.3 5.4 9.9 100-yr 24 hour 7.0 2.5 9.0 18.2 10-day snowmelt 0.1 0.1 0.2 0.4 Rainfall Event Proposed - North(cfs)2 Proposed – South (cfs)2 Proposed – Northwest (cfs) Proposed – Total (cfs)2 Existing – Total (cfs)1 2-yr 24 hour 1.3 0.4 2.8 4.4 4.4 10-yr 24 hour 2.6 0.9 4.8 8.1 8.2 100-yr 24 hour 5.3 1.8 8.1 14.8 14.9 10-day snowmelt 0.1 0.1 0.2 0.3 0.3 06 /30/2017 BONGARDS EXPANSION: STORMWATER MANAGEMEN T PLAN 4 in/hr (Appendix C). The maximum height for the infiltration volume with rock void space is 8”, and the proposed height for infiltration volume is 7”. Infiltration is proposed for the rock storage infiltration/filtration basin beneath the proposed parking lot and extends past the parking lot area, with a total surface area of 6,125 SF. The underdrains are elevated 7” above (0.58 ft) above the bottom of the feature. The provided infiltration volume provided the underground rock infiltration/filtration basin is 1,421 CF. Runoff from the proposed roof building will be directed to the underground infiltration/filtration basin, with sump manholes providing pretreatment. Provided Infiltration Volume: Infiltration Volume = 6,125 SF x 0.58 ft x 40% void space = 1,421 CF RPBCWD requires 90% TSS and 60% TP Removal. P8 was used to determine the nutrient loading provided by the additional impervious area (P8-Loading model), and the removals provided by the proposed underground rock storage infiltration/filtration basin with the proposed runoff going to the BMP (P8 – Removals model). 1 See Appendix D P8 report: Loading. 2 See Appendix D P8 report: Removal. CONCLUSION The proposed stormwater management plan for Bongards building and parking lot expansion will implement stormwater best management practices, providing sufficient retention and treatment for the 1.81-acre area to meet the City of Chanhassen’s and Riley Purgatory Bluff Creek Watershed District’s stormwater requirements. The proposed stormwater management plan consists of a proposed infiltration basin that also provides rate control. The site was modeled using HydroCAD for the existing and proposed 2-year, 10-year and 100-year events to confirm that the project meets the requirements of the City of Chanhassen and the Riley Purgatory Bluff Creek Watershed District. Our findings indicate the site will successfully achieve the Watershed goals for peak runoff, volume reduction, water quality and flood control. Water Quality Parameter Loading (lbs/yr)1 Removals (lbs/yr)2 % Removal Total Phosphorus (TP) 0.84 0.92 100% Total Suspended Solids (TSS) 261.74 307.73 100% 06 /30/2017 BONGARDS EXPANSION: STORMWATER MANAGEMEN T PLAN A APPENDIX A: DRAINAGE AREA MAPS Concre te S idewa lk Concr et e Si d e w al kStairsTrench drain LoadingDockTrash1 Story BuidingAddress: 8330 Commer ce D r iveFoundation Area: 9,558 Sq . F t .Drainage & Utility easement per plat52010 25 Minnesota Valley Natural Gas Company easementper Doc. No. 98299Southeasterly line of Northern States Power Company ea semen tper Doc. No. 72638Concrete Sidewalk10 10 10 55Drainage & Utility easementper plat Drai n a g e & Utilit y e a s e m e nt per pl at 2520 8" PVC8" D IP 18" RCP21" RCPRockRim=936 .6 (p lan ) Inv=926 .7 (p lan )MONCBRim=939 .6 Inv=0 .0FFE=942.8MON XFound open i ron p ipe Found open i ron p ipe FFE=942.8MON XCBRim=938.8CBRim=938.7STMHRim=939.3Inv=929.2FFE=942.8Found iron pipeRLS 18407STMHRim=934.6Inv=924.3Found iron pipeRLS 1840770.1 9.4 7.48.17.616.5 80.0 94.0104.1S33°02'37"E 341.26 (p) 341.37 (m)S56°57'24"W 238.00 (p) 238.01 (m) N33° 0 2' 3 6" W 3 3 0. 0 0 ( p) 3 3 0. 1 3 ( m)N56°57'24 "E 203 .00 (p ) 202 .70 (m ) 37. 3 7 Δ= 3 5 ° 4 1 ' 0 1 " R = 6 0 . 0 0 C = 3 7 . 1 1 (m ) 115 60 934.6DA-2(SOUTH-OVERLAND)Total: 33,551 SFImpervious: 27,400 SFPervious: 6,151 SFTotal Site Area : 78,666 sfImpervious: 27,950 sfPervious: 50,716 sfRATE CONTROL2-yr: 5.64 cfs10-yr: 9.94 cfs100-yr: 18.22 cfs10-day snowmelt: 0.35 cfsDA-1 (NORTH-OVERLAND)Total: 31,985 SFImpervious: 0 SFPervious: 31,985 SFDA-3(NORTHWEST-PIPE)Total: 13,130 SFImpervious: 550 SFPervious: 12,580 SFCADD USER: Nathan Warner FILE: C:\USERS\NATHAN W\DROPBOX\PROJECTS\160902 - BONGARDS CHANHASSEN - BDH+YOUNG\WORKING FILES\CAD\DWG\EX1.EXISTING-DA.160902-BONGARDS.DWG PLOT SCALE: 1:2 PLOT DATE: 6/29/2017 3:15 PM DRAWN BYCHECKED BYJOB NO.DATESHEETNJWSEG06.30.2017160902PROOF OF PARKING EXISTING DRAINAGE BUILDING AND PARKING EXPANSION BONGARDS CREAMERY CHANHASSEN, MINNESOTAEX-1SBINKnow what'sbelow.before you dig.CallR( IN FEET )DRAWING SCALEREVISIONS BYI HEREBY CERTIFY THAT THIS PLAN OR SPECIFICATION WAS PREPARED BY ME OR UNDER MY DIRECT SUPERVISION AND THAT I AM A DULY REGISTERED CIVIL ENGINEER UNDER THE LAWS OF THE STATE OF MINNESOTA Concre te S idewa lk Concr et e Si d e w al kStairsTrench drain LoadingDockTrash1 Story BuidingAddress: 8330 Commerce D r iveFoundation Area: 9,558 Sq . F t .Drainage & Utility easement per plat52010 25 Minnesota Valley Natural Gas Company easementper Doc. No. 98299Southeasterly line of Northern States Power Company ea semen tper Doc. No. 72638Concrete Sidewalk10 10 10 55Drainage & Utility easementper plat Drain a g e & Utilit y e a s e m e nt per pl at 2520 8" PVC8" D IP 18" RCP21" RCPRockRim=936 .6 (p lan ) Inv=926 .7 (p lan )MONCBRim=939 .6 Inv=0 .0FFE=942.8MON XFound open i ron p ipe Found open i ron p ipe FFE=942.8MON XCBRim=938.8CBRim=938.7STMHRim=939.3Inv=929.2FFE=942.8Found iron pipeRLS 18407STMHRim=934.6Inv=924.3Found iron pipeRLS 1840770.1 9.4 7.48.17.616.5 80.0 94.0104.1S33°02'37"E 341.26 (p) 341.37 (m)S56°57'24"W 238.00 (p) 238.01 (m) N33° 0 2' 3 6" W 3 3 0. 0 0 ( p) 3 3 0. 1 3 ( m)N56°57'24 "E 203 .00 (p ) 202 .70 (m ) 37. 3 7 Δ= 3 5 ° 4 1 ' 0 1 " R = 6 0 . 0 0 C = 3 7 . 1 1 (m ) 115 60 934.6Total: 8,725 SFImpervious: 550 SFPervious: 8,175 SFTotal Site Area : 78,666 SFImpervious: 41,878 SFPervious: 36,817 SF(Pervious Pavers = 1,224 SF)Total Disturbed Area: 26,424 SFTotal Disturbed Existing Impervious: 1,527 SFRATE CONTROL2-yr: 4.41 cfs10-yr: 8.17 cfs100-yr: 14.92 cfs10-day snowmelt: 0.34 cfsDA-1 (NORTH)Total: 23,885 SFImpervious: 192 SFPervious: 23,693 SFDA-3a (TO BMP)Total: 19,656 SFImpervious: 19,277 SFPervious: 379 SFP-1: UNDERGROUNDINFILTRATION/FILTRATION (6,125 SF)DA-3bTotal: 26,400 SFImpervious: 21,859 SFPervious: 4,541 SF(Pervious Pavers = 1,224 SF)DA-2 (SOUTH)PERVIOUS PAVERSCADD USER: Nathan Warner FILE: C:\USERS\NATHAN W\DROPBOX\PROJECTS\160902 - BONGARDS CHANHASSEN - BDH+YOUNG\WORKING FILES\CAD\DWG\EX2-PROOFOFPARKING_DA.160902-BONGARDS_06292017DWG.DWG PLOT SCALE: 1:2 PLOT DATE: 6/29/2017 4:10 PM DRAWN BYCHECKED BYJOB NO.DATESHEETNJWSEG06.30.2017160902PROOF OF PARKING PROPOSED DRAINAGE BUILDING AND PARKING EXPANSION BONGARDS CREAMERY CHANHASSEN, MINNESOTAEX-2SBINKnow what'sbelow.before you dig.CallR( IN FEET )DRAWING SCALEREVISIONS BYI HEREBY CERTIFY THAT THIS PLAN OR SPECIFICATION WAS PREPARED BY ME OR UNDER MY DIRECT SUPERVISION AND THAT I AM A DULY REGISTERED CIVIL ENGINEER UNDER THE LAWS OF THE STATE OF MINNESOTA 06/30/20 1 7 BONGARDS EXPANSION: STORMWATER MANAGEMEN T PLAN B APPENDIX B: HYDROCAD MODEL DA-1 DA1-ToNorth (Overland) DA-2 DA2-ToSouth (Overland) DA-3 DA3-ToNorthwest (Pipe) 1R To North (Overland) 2R To South (Overland) 3R Total Existing 5R To Northwest (pipe) Routing Diagram for Bongards_Existing_06292017 Prepared by Microsoft, Printed 6/29/2017 HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Subcat Reach Pond Link RPBCWD - 2-YR 24-hr 2y 24hr Rainfall=2.87"Bongards_Existing_06292017 Printed 6/29/2017Prepared by Microsoft Page 2HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Time span=5.00-240.00 hrs, dt=0.05 hrs, 4701 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=31,985 sf 0.00% Impervious Runoff Depth=1.15"Subcatchment DA-1: DA1-ToNorth (Overland) Flow Length=200' Slope=0.1000 '/' Tc=2.8 min CN=80 Runoff=1.69 cfs 0.071 af Runoff Area=13,130 sf 4.19% Impervious Runoff Depth=1.21"Subcatchment DA-2: DA2-ToSouth (Overland) Flow Length=225' Slope=0.0260 '/' Tc=5.8 min CN=81 Runoff=0.63 cfs 0.031 af Runoff Area=33,551 sf 81.67% Impervious Runoff Depth>2.32"Subcatchment DA-3: DA3-ToNorthwest (Pipe) Flow Length=200' Slope=0.0300 '/' Tc=2.8 min CN=95 Runoff=3.43 cfs 0.149 af Inflow=1.69 cfs 0.071 afReach 1R: To North (Overland) Outflow=1.69 cfs 0.071 af Inflow=0.63 cfs 0.031 afReach 2R: To South (Overland) Outflow=0.63 cfs 0.031 af Inflow=5.64 cfs 0.250 afReach 3R: Total Existing Outflow=5.64 cfs 0.250 af Inflow=3.43 cfs 0.149 afReach 5R: To Northwest (pipe) Outflow=3.43 cfs 0.149 af Total Runoff Area = 1.806 ac Runoff Volume = 0.250 af Average Runoff Depth = 1.66" 64.47% Pervious = 1.164 ac 35.53% Impervious = 0.642 ac RPBCWD - 2-YR 24-hr 2y 24hr Rainfall=2.87"Bongards_Existing_06292017 Printed 6/29/2017Prepared by Microsoft Page 3HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment DA-1: DA1-ToNorth (Overland) [49] Hint: Tc<2dt may require smaller dt [73] Warning: Peak may fall outside time span Runoff =1.69 cfs @ 12.05 hrs, Volume=0.071 af, Depth=1.15" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - 2-YR 24-hr 2y 24hr Rainfall=2.87" Area (sf)CN Description 31,985 80 >75% Grass cover, Good, HSG D 31,985 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 2.8 200 0.1000 1.20 Lag/CN Method, Summary for Subcatchment DA-2: DA2-ToSouth (Overland) [49] Hint: Tc<2dt may require smaller dt [73] Warning: Peak may fall outside time span Runoff =0.63 cfs @ 12.09 hrs, Volume=0.031 af, Depth=1.21" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - 2-YR 24-hr 2y 24hr Rainfall=2.87" Area (sf)CN Description *550 98 impervious 12,580 80 >75% Grass cover, Good, HSG D 13,130 81 Weighted Average 12,580 95.81% Pervious Area 550 4.19% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.8 225 0.0260 0.65 Lag/CN Method, Summary for Subcatchment DA-3: DA3-ToNorthwest (Pipe) [49] Hint: Tc<2dt may require smaller dt [73] Warning: Peak may fall outside time span Runoff =3.43 cfs @ 12.04 hrs, Volume=0.149 af, Depth>2.32" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - 2-YR 24-hr 2y 24hr Rainfall=2.87" RPBCWD - 2-YR 24-hr 2y 24hr Rainfall=2.87"Bongards_Existing_06292017 Printed 6/29/2017Prepared by Microsoft Page 4HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Area (sf)CN Description *27,400 98 impervious 6,151 80 >75% Grass cover, Good, HSG D 33,551 95 Weighted Average 6,151 18.33% Pervious Area 27,400 81.67% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 2.8 200 0.0300 1.18 Lag/CN Method, Summary for Reach 1R: To North (Overland) [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.734 ac,0.00% Impervious, Inflow Depth = 1.15" for 2y 24hr event Inflow =1.69 cfs @ 12.05 hrs, Volume=0.071 af Outflow =1.69 cfs @ 12.05 hrs, Volume=0.071 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Summary for Reach 2R: To South (Overland) [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.301 ac,4.19% Impervious, Inflow Depth = 1.21" for 2y 24hr event Inflow =0.63 cfs @ 12.09 hrs, Volume=0.031 af Outflow =0.63 cfs @ 12.09 hrs, Volume=0.031 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Summary for Reach 3R: Total Existing [40] Hint: Not Described (Outflow=Inflow) Inflow Area =1.806 ac,35.53% Impervious, Inflow Depth > 1.66" for 2y 24hr event Inflow =5.64 cfs @ 12.05 hrs, Volume=0.250 af Outflow =5.64 cfs @ 12.05 hrs, Volume=0.250 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Summary for Reach 5R: To Northwest (pipe) [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.770 ac,81.67% Impervious, Inflow Depth > 2.32" for 2y 24hr event Inflow =3.43 cfs @ 12.04 hrs, Volume=0.149 af Outflow =3.43 cfs @ 12.04 hrs, Volume=0.149 af, Atten= 0%, Lag= 0.0 min RPBCWD - 2-YR 24-hr 2y 24hr Rainfall=2.87"Bongards_Existing_06292017 Printed 6/29/2017Prepared by Microsoft Page 5HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - SNOWMELT 10 day snowmelt Rainfall=7.20", AMC=4Bongards_Existing_06292017 Printed 6/29/2017Prepared by Microsoft Page 6HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Time span=5.00-240.00 hrs, dt=0.05 hrs, 4701 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=31,985 sf 0.00% Impervious Runoff Depth>6.96"Subcatchment DA-1: DA1-ToNorth (Overland) Flow Length=200' Slope=0.1000 '/' Tc=2.8 min AMC Adjusted CN=98 Runoff=0.14 cfs 0.426 af Runoff Area=13,130 sf 4.19% Impervious Runoff Depth>6.96"Subcatchment DA-2: DA2-ToSouth (Overland) Flow Length=225' Slope=0.0260 '/' Tc=5.8 min AMC Adjusted CN=98 Runoff=0.06 cfs 0.175 af Runoff Area=33,551 sf 81.67% Impervious Runoff Depth>6.96"Subcatchment DA-3: DA3-ToNorthwest (Pipe) Flow Length=200' Slope=0.0300 '/' Tc=2.8 min AMC Adjusted CN=98 Runoff=0.15 cfs 0.447 af Inflow=0.14 cfs 0.426 afReach 1R: To North (Overland) Outflow=0.14 cfs 0.426 af Inflow=0.06 cfs 0.175 afReach 2R: To South (Overland) Outflow=0.06 cfs 0.175 af Inflow=0.35 cfs 1.048 afReach 3R: Total Existing Outflow=0.35 cfs 1.048 af Inflow=0.15 cfs 0.447 afReach 5R: To Northwest (pipe) Outflow=0.15 cfs 0.447 af Total Runoff Area = 1.806 ac Runoff Volume = 1.048 af Average Runoff Depth = 6.96" 64.47% Pervious = 1.164 ac 35.53% Impervious = 0.642 ac RPBCWD - SNOWMELT 10 day snowmelt Rainfall=7.20", AMC=4Bongards_Existing_06292017 Printed 6/29/2017Prepared by Microsoft Page 7HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment DA-1: DA1-ToNorth (Overland) [49] Hint: Tc<2dt may require smaller dt Runoff =0.14 cfs @ 121.21 hrs, Volume=0.426 af, Depth>6.96" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - SNOWMELT 10 day snowmelt Rainfall=7.20", AMC=4 Area (sf)CN Adj Description 31,985 80 >75% Grass cover, Good, HSG D 31,985 80 98 Weighted Average, AMC Adjusted 31,985 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 2.8 200 0.1000 1.20 Lag/CN Method, Summary for Subcatchment DA-2: DA2-ToSouth (Overland) [49] Hint: Tc<2dt may require smaller dt Runoff =0.06 cfs @ 121.25 hrs, Volume=0.175 af, Depth>6.96" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - SNOWMELT 10 day snowmelt Rainfall=7.20", AMC=4 Area (sf)CN Adj Description *550 98 impervious 12,580 80 >75% Grass cover, Good, HSG D 13,130 81 98 Weighted Average, AMC Adjusted 12,580 95.81% Pervious Area 550 4.19% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.8 225 0.0260 0.65 Lag/CN Method, Summary for Subcatchment DA-3: DA3-ToNorthwest (Pipe) [49] Hint: Tc<2dt may require smaller dt Runoff =0.15 cfs @ 121.21 hrs, Volume=0.447 af, Depth>6.96" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - SNOWMELT 10 day snowmelt Rainfall=7.20", AMC=4 RPBCWD - SNOWMELT 10 day snowmelt Rainfall=7.20", AMC=4Bongards_Existing_06292017 Printed 6/29/2017Prepared by Microsoft Page 8HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Area (sf)CN Adj Description *27,400 98 impervious 6,151 80 >75% Grass cover, Good, HSG D 33,551 95 98 Weighted Average, AMC Adjusted 6,151 18.33% Pervious Area 27,400 81.67% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 2.8 200 0.0300 1.18 Lag/CN Method, Summary for Reach 1R: To North (Overland) [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.734 ac,0.00% Impervious, Inflow Depth > 6.96" for 10 day snowmelt event Inflow =0.14 cfs @ 121.21 hrs, Volume=0.426 af Outflow =0.14 cfs @ 121.21 hrs, Volume=0.426 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Summary for Reach 2R: To South (Overland) [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.301 ac,4.19% Impervious, Inflow Depth > 6.96" for 10 day snowmelt event Inflow =0.06 cfs @ 121.25 hrs, Volume=0.175 af Outflow =0.06 cfs @ 121.25 hrs, Volume=0.175 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Summary for Reach 3R: Total Existing [40] Hint: Not Described (Outflow=Inflow) Inflow Area =1.806 ac,35.53% Impervious, Inflow Depth > 6.96" for 10 day snowmelt event Inflow =0.35 cfs @ 121.21 hrs, Volume=1.048 af Outflow =0.35 cfs @ 121.21 hrs, Volume=1.048 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Summary for Reach 5R: To Northwest (pipe) [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.770 ac,81.67% Impervious, Inflow Depth > 6.96" for 10 day snowmelt event Inflow =0.15 cfs @ 121.21 hrs, Volume=0.447 af Outflow =0.15 cfs @ 121.21 hrs, Volume=0.447 af, Atten= 0%, Lag= 0.0 min RPBCWD - SNOWMELT 10 day snowmelt Rainfall=7.20", AMC=4Bongards_Existing_06292017 Printed 6/29/2017Prepared by Microsoft Page 9HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - 10-YR 24-hr 10y 24hr Rainfall=4.27"Bongards_Existing_06292017 Printed 6/29/2017Prepared by Microsoft Page 10HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Time span=5.00-240.00 hrs, dt=0.05 hrs, 4701 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=31,985 sf 0.00% Impervious Runoff Depth=2.27"Subcatchment DA-1: DA1-ToNorth (Overland) Flow Length=200' Slope=0.1000 '/' Tc=2.8 min CN=80 Runoff=3.45 cfs 0.139 af Runoff Area=13,130 sf 4.19% Impervious Runoff Depth=2.35"Subcatchment DA-2: DA2-ToSouth (Overland) Flow Length=225' Slope=0.0260 '/' Tc=5.8 min CN=81 Runoff=1.25 cfs 0.059 af Runoff Area=33,551 sf 81.67% Impervious Runoff Depth>3.70"Subcatchment DA-3: DA3-ToNorthwest (Pipe) Flow Length=200' Slope=0.0300 '/' Tc=2.8 min CN=95 Runoff=5.43 cfs 0.237 af Inflow=3.45 cfs 0.139 afReach 1R: To North (Overland) Outflow=3.45 cfs 0.139 af Inflow=1.25 cfs 0.059 afReach 2R: To South (Overland) Outflow=1.25 cfs 0.059 af Inflow=9.94 cfs 0.435 afReach 3R: Total Existing Outflow=9.94 cfs 0.435 af Inflow=5.43 cfs 0.237 afReach 5R: To Northwest (pipe) Outflow=5.43 cfs 0.237 af Total Runoff Area = 1.806 ac Runoff Volume = 0.435 af Average Runoff Depth = 2.89" 64.47% Pervious = 1.164 ac 35.53% Impervious = 0.642 ac RPBCWD - 10-YR 24-hr 10y 24hr Rainfall=4.27"Bongards_Existing_06292017 Printed 6/29/2017Prepared by Microsoft Page 11HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment DA-1: DA1-ToNorth (Overland) [49] Hint: Tc<2dt may require smaller dt [73] Warning: Peak may fall outside time span Runoff =3.45 cfs @ 12.05 hrs, Volume=0.139 af, Depth=2.27" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - 10-YR 24-hr 10y 24hr Rainfall=4.27" Area (sf)CN Description 31,985 80 >75% Grass cover, Good, HSG D 31,985 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 2.8 200 0.1000 1.20 Lag/CN Method, Summary for Subcatchment DA-2: DA2-ToSouth (Overland) [49] Hint: Tc<2dt may require smaller dt [73] Warning: Peak may fall outside time span Runoff =1.25 cfs @ 12.09 hrs, Volume=0.059 af, Depth=2.35" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - 10-YR 24-hr 10y 24hr Rainfall=4.27" Area (sf)CN Description *550 98 impervious 12,580 80 >75% Grass cover, Good, HSG D 13,130 81 Weighted Average 12,580 95.81% Pervious Area 550 4.19% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.8 225 0.0260 0.65 Lag/CN Method, Summary for Subcatchment DA-3: DA3-ToNorthwest (Pipe) [49] Hint: Tc<2dt may require smaller dt [73] Warning: Peak may fall outside time span Runoff =5.43 cfs @ 12.04 hrs, Volume=0.237 af, Depth>3.70" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - 10-YR 24-hr 10y 24hr Rainfall=4.27" RPBCWD - 10-YR 24-hr 10y 24hr Rainfall=4.27"Bongards_Existing_06292017 Printed 6/29/2017Prepared by Microsoft Page 12HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Area (sf)CN Description *27,400 98 impervious 6,151 80 >75% Grass cover, Good, HSG D 33,551 95 Weighted Average 6,151 18.33% Pervious Area 27,400 81.67% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 2.8 200 0.0300 1.18 Lag/CN Method, Summary for Reach 1R: To North (Overland) [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.734 ac,0.00% Impervious, Inflow Depth = 2.27" for 10y 24hr event Inflow =3.45 cfs @ 12.05 hrs, Volume=0.139 af Outflow =3.45 cfs @ 12.05 hrs, Volume=0.139 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Summary for Reach 2R: To South (Overland) [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.301 ac,4.19% Impervious, Inflow Depth = 2.35" for 10y 24hr event Inflow =1.25 cfs @ 12.09 hrs, Volume=0.059 af Outflow =1.25 cfs @ 12.09 hrs, Volume=0.059 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Summary for Reach 3R: Total Existing [40] Hint: Not Described (Outflow=Inflow) Inflow Area =1.806 ac,35.53% Impervious, Inflow Depth > 2.89" for 10y 24hr event Inflow =9.94 cfs @ 12.05 hrs, Volume=0.435 af Outflow =9.94 cfs @ 12.05 hrs, Volume=0.435 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Summary for Reach 5R: To Northwest (pipe) [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.770 ac,81.67% Impervious, Inflow Depth > 3.70" for 10y 24hr event Inflow =5.43 cfs @ 12.04 hrs, Volume=0.237 af Outflow =5.43 cfs @ 12.04 hrs, Volume=0.237 af, Atten= 0%, Lag= 0.0 min RPBCWD - 10-YR 24-hr 10y 24hr Rainfall=4.27"Bongards_Existing_06292017 Printed 6/29/2017Prepared by Microsoft Page 13HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - 100-YR 24-hr 100y 24hr Rainfall=7.41"Bongards_Existing_06292017 Printed 6/29/2017Prepared by Microsoft Page 14HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Time span=5.00-240.00 hrs, dt=0.05 hrs, 4701 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=31,985 sf 0.00% Impervious Runoff Depth=5.07"Subcatchment DA-1: DA1-ToNorth (Overland) Flow Length=200' Slope=0.1000 '/' Tc=2.8 min CN=80 Runoff=7.04 cfs 0.310 af Runoff Area=13,130 sf 4.19% Impervious Runoff Depth=5.19"Subcatchment DA-2: DA2-ToSouth (Overland) Flow Length=225' Slope=0.0260 '/' Tc=5.8 min CN=81 Runoff=2.52 cfs 0.130 af Runoff Area=33,551 sf 81.67% Impervious Runoff Depth>6.81"Subcatchment DA-3: DA3-ToNorthwest (Pipe) Flow Length=200' Slope=0.0300 '/' Tc=2.8 min CN=95 Runoff=8.97 cfs 0.437 af Inflow=7.04 cfs 0.310 afReach 1R: To North (Overland) Outflow=7.04 cfs 0.310 af Inflow=2.52 cfs 0.130 afReach 2R: To South (Overland) Outflow=2.52 cfs 0.130 af Inflow=18.22 cfs 0.878 afReach 3R: Total Existing Outflow=18.22 cfs 0.878 af Inflow=8.97 cfs 0.437 afReach 5R: To Northwest (pipe) Outflow=8.97 cfs 0.437 af Total Runoff Area = 1.806 ac Runoff Volume = 0.878 af Average Runoff Depth = 5.83" 64.47% Pervious = 1.164 ac 35.53% Impervious = 0.642 ac RPBCWD - 100-YR 24-hr 100y 24hr Rainfall=7.41"Bongards_Existing_06292017 Printed 6/29/2017Prepared by Microsoft Page 15HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment DA-1: DA1-ToNorth (Overland) [49] Hint: Tc<2dt may require smaller dt [73] Warning: Peak may fall outside time span Runoff =7.04 cfs @ 12.05 hrs, Volume=0.310 af, Depth=5.07" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - 100-YR 24-hr 100y 24hr Rainfall=7.41" Area (sf)CN Description 31,985 80 >75% Grass cover, Good, HSG D 31,985 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 2.8 200 0.1000 1.20 Lag/CN Method, Summary for Subcatchment DA-2: DA2-ToSouth (Overland) [49] Hint: Tc<2dt may require smaller dt [73] Warning: Peak may fall outside time span Runoff =2.52 cfs @ 12.09 hrs, Volume=0.130 af, Depth=5.19" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - 100-YR 24-hr 100y 24hr Rainfall=7.41" Area (sf)CN Description *550 98 impervious 12,580 80 >75% Grass cover, Good, HSG D 13,130 81 Weighted Average 12,580 95.81% Pervious Area 550 4.19% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.8 225 0.0260 0.65 Lag/CN Method, Summary for Subcatchment DA-3: DA3-ToNorthwest (Pipe) [49] Hint: Tc<2dt may require smaller dt [73] Warning: Peak may fall outside time span Runoff =8.97 cfs @ 12.04 hrs, Volume=0.437 af, Depth>6.81" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - 100-YR 24-hr 100y 24hr Rainfall=7.41" RPBCWD - 100-YR 24-hr 100y 24hr Rainfall=7.41"Bongards_Existing_06292017 Printed 6/29/2017Prepared by Microsoft Page 16HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Area (sf)CN Description *27,400 98 impervious 6,151 80 >75% Grass cover, Good, HSG D 33,551 95 Weighted Average 6,151 18.33% Pervious Area 27,400 81.67% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 2.8 200 0.0300 1.18 Lag/CN Method, Summary for Reach 1R: To North (Overland) [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.734 ac,0.00% Impervious, Inflow Depth = 5.07" for 100y 24hr event Inflow =7.04 cfs @ 12.05 hrs, Volume=0.310 af Outflow =7.04 cfs @ 12.05 hrs, Volume=0.310 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Summary for Reach 2R: To South (Overland) [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.301 ac,4.19% Impervious, Inflow Depth = 5.19" for 100y 24hr event Inflow =2.52 cfs @ 12.09 hrs, Volume=0.130 af Outflow =2.52 cfs @ 12.09 hrs, Volume=0.130 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Summary for Reach 3R: Total Existing [40] Hint: Not Described (Outflow=Inflow) Inflow Area =1.806 ac,35.53% Impervious, Inflow Depth > 5.83" for 100y 24hr event Inflow =18.22 cfs @ 12.05 hrs, Volume=0.878 af Outflow =18.22 cfs @ 12.05 hrs, Volume=0.878 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Summary for Reach 5R: To Northwest (pipe) [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.770 ac,81.67% Impervious, Inflow Depth > 6.81" for 100y 24hr event Inflow =8.97 cfs @ 12.04 hrs, Volume=0.437 af Outflow =8.97 cfs @ 12.04 hrs, Volume=0.437 af, Atten= 0%, Lag= 0.0 min RPBCWD - 100-YR 24-hr 100y 24hr Rainfall=7.41"Bongards_Existing_06292017 Printed 6/29/2017Prepared by Microsoft Page 17HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs DA-1 DA1-ToNorth (Overland) DA-2 DA2-ToSouth (Overland) DA-3a DA3a-ToBMP DA-3b DA3b-ToNorthwest (Pipe) 1R To North 2R To South 3R Total Proposed 4R To Northwest (pipe) 12P Underground treatment-10" pipe, 4" cover, minimum 440 LF, SA 6125 SF Routing Diagram for Bongards_ProofofParking_06292017 Prepared by Microsoft, Printed 6/29/2017 HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Subcat Reach Pond Link RPBCWD - 2-YR 24-hr 2y 24hr Rainfall=2.87"Bongards_ProofofParking_06292017 Printed 6/29/2017Prepared by Microsoft Page 2HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Time span=5.00-240.00 hrs, dt=0.05 hrs, 4701 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=23,885 sf 0.80% Impervious Runoff Depth=1.15"Subcatchment DA-1: DA1-ToNorth (Overland) Flow Length=200' Slope=0.1000 '/' Tc=2.8 min CN=80 Runoff=1.26 cfs 0.053 af Runoff Area=9,275 sf 5.93% Impervious Runoff Depth=1.21"Subcatchment DA-2: DA2-ToSouth (Overland) Flow Length=225' Slope=0.0260 '/' Tc=5.8 min CN=81 Runoff=0.44 cfs 0.022 af Runoff Area=19,656 sf 98.07% Impervious Runoff Depth>2.61"Subcatchment DA-3a: DA3a-ToBMP Flow Length=200' Slope=0.0100 '/' Tc=4.2 min CN=98 Runoff=2.01 cfs 0.098 af Runoff Area=26,400 sf 82.80% Impervious Runoff Depth>2.32"Subcatchment DA-3b: DA3b-ToNorthwest Flow Length=150' Slope=0.0100 '/' Tc=3.9 min CN=95 Runoff=2.57 cfs 0.117 af Inflow=1.26 cfs 0.053 afReach 1R: To North Outflow=1.26 cfs 0.053 af Inflow=0.44 cfs 0.022 afReach 2R: To South Outflow=0.44 cfs 0.022 af Inflow=4.41 cfs 0.261 afReach 3R: Total Proposed Outflow=4.41 cfs 0.261 af Inflow=2.77 cfs 0.187 afReach 4R: To Northwest (pipe) Outflow=2.77 cfs 0.187 af Peak Elev=937.13' Storage=2,339 cf Inflow=2.01 cfs 0.098 afPond 12P: Underground treatment-10" pipe, 4" Outflow=0.53 cfs 0.070 af Total Runoff Area = 1.819 ac Runoff Volume = 0.290 af Average Runoff Depth = 1.91" 47.13% Pervious = 0.857 ac 52.87% Impervious = 0.961 ac RPBCWD - 2-YR 24-hr 2y 24hr Rainfall=2.87"Bongards_ProofofParking_06292017 Printed 6/29/2017Prepared by Microsoft Page 3HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment DA-1: DA1-ToNorth (Overland) [49] Hint: Tc<2dt may require smaller dt [73] Warning: Peak may fall outside time span Runoff =1.26 cfs @ 12.05 hrs, Volume=0.053 af, Depth=1.15" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - 2-YR 24-hr 2y 24hr Rainfall=2.87" Area (sf)CN Description 23,693 80 >75% Grass cover, Good, HSG D 192 98 Unconnected pavement, HSG D 23,885 80 Weighted Average 23,693 99.20% Pervious Area 192 0.80% Impervious Area 192 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 2.8 200 0.1000 1.20 Lag/CN Method, Summary for Subcatchment DA-2: DA2-ToSouth (Overland) [49] Hint: Tc<2dt may require smaller dt [73] Warning: Peak may fall outside time span Runoff =0.44 cfs @ 12.09 hrs, Volume=0.022 af, Depth=1.21" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - 2-YR 24-hr 2y 24hr Rainfall=2.87" Area (sf)CN Description *550 98 impervious 8,725 80 >75% Grass cover, Good, HSG D 9,275 81 Weighted Average 8,725 94.07% Pervious Area 550 5.93% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.8 225 0.0260 0.65 Lag/CN Method, Summary for Subcatchment DA-3a: DA3a-ToBMP [49] Hint: Tc<2dt may require smaller dt [73] Warning: Peak may fall outside time span Runoff =2.01 cfs @ 12.06 hrs, Volume=0.098 af, Depth>2.61" RPBCWD - 2-YR 24-hr 2y 24hr Rainfall=2.87"Bongards_ProofofParking_06292017 Printed 6/29/2017Prepared by Microsoft Page 4HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - 2-YR 24-hr 2y 24hr Rainfall=2.87" Area (sf)CN Description *19,277 98 impervious 379 80 >75% Grass cover, Good, HSG D 19,656 98 Weighted Average 379 1.93% Pervious Area 19,277 98.07% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 4.2 200 0.0100 0.80 Lag/CN Method, Summary for Subcatchment DA-3b: DA3b-ToNorthwest (Pipe) [49] Hint: Tc<2dt may require smaller dt [73] Warning: Peak may fall outside time span Runoff =2.57 cfs @ 12.06 hrs, Volume=0.117 af, Depth>2.32" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - 2-YR 24-hr 2y 24hr Rainfall=2.87" Area (sf)CN Description *21,859 98 impervious 3,317 80 >75% Grass cover, Good, HSG D *1,224 80 Pervious Pavers 26,400 95 Weighted Average 4,541 17.20% Pervious Area 21,859 82.80% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 3.9 150 0.0100 0.64 Lag/CN Method, Summary for Reach 1R: To North [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.548 ac,0.80% Impervious, Inflow Depth = 1.15" for 2y 24hr event Inflow =1.26 cfs @ 12.05 hrs, Volume=0.053 af Outflow =1.26 cfs @ 12.05 hrs, Volume=0.053 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - 2-YR 24-hr 2y 24hr Rainfall=2.87"Bongards_ProofofParking_06292017 Printed 6/29/2017Prepared by Microsoft Page 5HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Summary for Reach 2R: To South [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.213 ac,5.93% Impervious, Inflow Depth = 1.21" for 2y 24hr event Inflow =0.44 cfs @ 12.09 hrs, Volume=0.022 af Outflow =0.44 cfs @ 12.09 hrs, Volume=0.022 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Summary for Reach 3R: Total Proposed [40] Hint: Not Described (Outflow=Inflow) Inflow Area =1.819 ac,52.87% Impervious, Inflow Depth > 1.73" for 2y 24hr event Inflow =4.41 cfs @ 12.06 hrs, Volume=0.261 af Outflow =4.41 cfs @ 12.06 hrs, Volume=0.261 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Summary for Reach 4R: To Northwest (pipe) [40] Hint: Not Described (Outflow=Inflow) Inflow Area =1.057 ac,89.32% Impervious, Inflow Depth > 2.13" for 2y 24hr event Inflow =2.77 cfs @ 12.06 hrs, Volume=0.187 af Outflow =2.77 cfs @ 12.06 hrs, Volume=0.187 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Summary for Pond 12P: Underground treatment-10" pipe, 4" cover, minimum 440 LF, SA 6125 SF [82] Warning: Early inflow requires earlier time span Inflow Area =0.451 ac,98.07% Impervious, Inflow Depth > 2.61" for 2y 24hr event Inflow =2.01 cfs @ 12.06 hrs, Volume=0.098 af Outflow =0.53 cfs @ 12.27 hrs, Volume=0.070 af, Atten= 74%, Lag= 12.9 min Primary =0.53 cfs @ 12.27 hrs, Volume=0.070 af Routing by Stor-Ind method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Peak Elev= 937.13' @ 12.27 hrs Surf.Area= 6,104 sf Storage= 2,339 cf Plug-Flow detention time= 225.4 min calculated for 0.070 af (71% of inflow) Center-of-Mass det. time= 151.1 min ( 912.9 - 761.7 ) Volume Invert Avail.Storage Storage Description #1A 936.20'4,353 cf 145.33'W x 42.00'L x 1.83'H Field A 11,191 cf Overall - 309 cf Embedded = 10,882 cf x 40.0% Voids #2A 936.70'309 cf CPP 10 x 22 Inside #1 Inside= 10.0"W x 10.0"H => 0.70 sf x 20.00'L = 14.0 cf Outside= 12.0"W x 12.0"H => 0.70 sf x 20.00'L = 14.0 cf RPBCWD - 2-YR 24-hr 2y 24hr Rainfall=2.87"Bongards_ProofofParking_06292017 Printed 6/29/2017Prepared by Microsoft Page 6HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC 11 Rows of 2 Chambers 4,661 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 933.96'10.0" Round Culvert L= 16.0' CPP, end-section conforming to fill, Ke= 0.500 Inlet / Outlet Invert= 933.96' / 933.00' S= 0.0600 '/' Cc= 0.900 n= 0.010 PVC, smooth interior, Flow Area= 0.55 sf #2 Device 1 937.70'4.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) #3 Device 1 936.70'8.0" Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=0.52 cfs @ 12.27 hrs HW=937.13' (Free Discharge) 1=Culvert (Passes 0.52 cfs of 4.35 cfs potential flow) 2=Sharp-Crested Rectangular Weir ( Controls 0.00 cfs) 3=Orifice/Grate (Orifice Controls 0.52 cfs @ 2.22 fps) RPBCWD - SNOWMELT 10 day snowmelt Rainfall=7.20", AMC=4Bongards_ProofofParking_06 Printed 6/29/2017Prepared by Microsoft Page 7HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Time span=5.00-240.00 hrs, dt=0.05 hrs, 4701 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=23,885 sf 0.80% Impervious Runoff Depth>6.96"Subcatchment DA-1: DA1-ToNorth (Overland) Flow Length=200' Slope=0.1000 '/' Tc=2.8 min AMC UI Adjusted CN=98 Runoff=0.10 cfs 0.318 af Runoff Area=9,275 sf 5.93% Impervious Runoff Depth>6.96"Subcatchment DA-2: DA2-ToSouth (Overland) Flow Length=225' Slope=0.0260 '/' Tc=5.8 min AMC Adjusted CN=98 Runoff=0.04 cfs 0.123 af Runoff Area=19,656 sf 98.07% Impervious Runoff Depth>6.96"Subcatchment DA-3a: DA3a-ToBMP Flow Length=200' Slope=0.0100 '/' Tc=4.2 min CN=98 Runoff=0.09 cfs 0.262 af Runoff Area=26,400 sf 82.80% Impervious Runoff Depth>6.96"Subcatchment DA-3b: DA3b-ToNorthwest Flow Length=150' Slope=0.0100 '/' Tc=3.9 min AMC Adjusted CN=98 Runoff=0.12 cfs 0.352 af Inflow=0.10 cfs 0.318 afReach 1R: To North Outflow=0.10 cfs 0.318 af Inflow=0.04 cfs 0.123 afReach 2R: To South Outflow=0.04 cfs 0.123 af Inflow=0.34 cfs 1.024 afReach 3R: Total Proposed Outflow=0.34 cfs 1.024 af Inflow=0.20 cfs 0.583 afReach 4R: To Northwest (pipe) Outflow=0.20 cfs 0.583 af Peak Elev=936.86' Storage=1,615 cf Inflow=0.09 cfs 0.262 afPond 12P: Underground treatment-10" pipe, 4" Outflow=0.08 cfs 0.231 af Total Runoff Area = 1.819 ac Runoff Volume = 1.055 af Average Runoff Depth = 6.96" 47.13% Pervious = 0.857 ac 52.87% Impervious = 0.961 ac RPBCWD - SNOWMELT 10 day snowmelt Rainfall=7.20", AMC=4Bongards_ProofofParking_06 Printed 6/29/2017Prepared by Microsoft Page 8HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment DA-1: DA1-ToNorth (Overland) [49] Hint: Tc<2dt may require smaller dt Runoff =0.10 cfs @ 121.21 hrs, Volume=0.318 af, Depth>6.96" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - SNOWMELT 10 day snowmelt Rainfall=7.20", AMC=4 Area (sf)CN Adj Description 23,693 80 >75% Grass cover, Good, HSG D 192 98 Unconnected pavement, HSG D 23,885 80 98 Weighted Average, AMC UI Adjusted 23,693 99.20% Pervious Area 192 0.80% Impervious Area 192 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 2.8 200 0.1000 1.20 Lag/CN Method, Summary for Subcatchment DA-2: DA2-ToSouth (Overland) [49] Hint: Tc<2dt may require smaller dt Runoff =0.04 cfs @ 121.25 hrs, Volume=0.123 af, Depth>6.96" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - SNOWMELT 10 day snowmelt Rainfall=7.20", AMC=4 Area (sf)CN Adj Description *550 98 impervious 8,725 80 >75% Grass cover, Good, HSG D 9,275 81 98 Weighted Average, AMC Adjusted 8,725 94.07% Pervious Area 550 5.93% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.8 225 0.0260 0.65 Lag/CN Method, Summary for Subcatchment DA-3a: DA3a-ToBMP [49] Hint: Tc<2dt may require smaller dt Runoff =0.09 cfs @ 121.23 hrs, Volume=0.262 af, Depth>6.96" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - SNOWMELT 10 day snowmelt Rainfall=7.20", AMC=4 RPBCWD - SNOWMELT 10 day snowmelt Rainfall=7.20", AMC=4Bongards_ProofofParking_06 Printed 6/29/2017Prepared by Microsoft Page 9HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Area (sf)CN Description *19,277 98 impervious 379 80 >75% Grass cover, Good, HSG D 19,656 98 Weighted Average 379 1.93% Pervious Area 19,277 98.07% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 4.2 200 0.0100 0.80 Lag/CN Method, Summary for Subcatchment DA-3b: DA3b-ToNorthwest (Pipe) [49] Hint: Tc<2dt may require smaller dt Runoff =0.12 cfs @ 121.23 hrs, Volume=0.352 af, Depth>6.96" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - SNOWMELT 10 day snowmelt Rainfall=7.20", AMC=4 Area (sf)CN Adj Description *21,859 98 impervious 3,317 80 >75% Grass cover, Good, HSG D *1,224 80 Pervious Pavers 26,400 95 98 Weighted Average, AMC Adjusted 4,541 17.20% Pervious Area 21,859 82.80% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 3.9 150 0.0100 0.64 Lag/CN Method, Summary for Reach 1R: To North [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.548 ac,0.80% Impervious, Inflow Depth > 6.96" for 10 day snowmelt event Inflow =0.10 cfs @ 121.21 hrs, Volume=0.318 af Outflow =0.10 cfs @ 121.21 hrs, Volume=0.318 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Summary for Reach 2R: To South [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.213 ac,5.93% Impervious, Inflow Depth > 6.96" for 10 day snowmelt event Inflow =0.04 cfs @ 121.25 hrs, Volume=0.123 af Outflow =0.04 cfs @ 121.25 hrs, Volume=0.123 af, Atten= 0%, Lag= 0.0 min RPBCWD - SNOWMELT 10 day snowmelt Rainfall=7.20", AMC=4Bongards_ProofofParking_06 Printed 6/29/2017Prepared by Microsoft Page 10HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Summary for Reach 3R: Total Proposed [40] Hint: Not Described (Outflow=Inflow) Inflow Area =1.819 ac,52.87% Impervious, Inflow Depth > 6.76" for 10 day snowmelt event Inflow =0.34 cfs @ 121.23 hrs, Volume=1.024 af Outflow =0.34 cfs @ 121.23 hrs, Volume=1.024 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Summary for Reach 4R: To Northwest (pipe) [40] Hint: Not Described (Outflow=Inflow) Inflow Area =1.057 ac,89.32% Impervious, Inflow Depth > 6.62" for 10 day snowmelt event Inflow =0.20 cfs @ 121.25 hrs, Volume=0.583 af Outflow =0.20 cfs @ 121.25 hrs, Volume=0.583 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Summary for Pond 12P: Underground treatment-10" pipe, 4" cover, minimum 440 LF, SA 6125 SF Inflow Area =0.451 ac,98.07% Impervious, Inflow Depth > 6.96" for 10 day snowmelt event Inflow =0.09 cfs @ 121.23 hrs, Volume=0.262 af Outflow =0.08 cfs @ 121.52 hrs, Volume=0.231 af, Atten= 4%, Lag= 17.4 min Primary =0.08 cfs @ 121.52 hrs, Volume=0.231 af Routing by Stor-Ind method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Peak Elev= 936.86' @ 121.52 hrs Surf.Area= 6,104 sf Storage= 1,615 cf Plug-Flow detention time= 1,462.9 min calculated for 0.231 af (88% of inflow) Center-of-Mass det. time= 745.1 min ( 8,124.8 - 7,379.7 ) Volume Invert Avail.Storage Storage Description #1A 936.20'4,353 cf 145.33'W x 42.00'L x 1.83'H Field A 11,191 cf Overall - 309 cf Embedded = 10,882 cf x 40.0% Voids #2A 936.70'309 cf CPP 10 x 22 Inside #1 Inside= 10.0"W x 10.0"H => 0.70 sf x 20.00'L = 14.0 cf Outside= 12.0"W x 12.0"H => 0.70 sf x 20.00'L = 14.0 cf 11 Rows of 2 Chambers 4,661 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 933.96'10.0" Round Culvert L= 16.0' CPP, end-section conforming to fill, Ke= 0.500 Inlet / Outlet Invert= 933.96' / 933.00' S= 0.0600 '/' Cc= 0.900 n= 0.010 PVC, smooth interior, Flow Area= 0.55 sf RPBCWD - SNOWMELT 10 day snowmelt Rainfall=7.20", AMC=4Bongards_ProofofParking_06 Printed 6/29/2017Prepared by Microsoft Page 11HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC #2 Device 1 937.70'4.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) #3 Device 1 936.70'8.0" Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=0.08 cfs @ 121.52 hrs HW=936.86' (Free Discharge) 1=Culvert (Passes 0.08 cfs of 4.13 cfs potential flow) 2=Sharp-Crested Rectangular Weir ( Controls 0.00 cfs) 3=Orifice/Grate (Orifice Controls 0.08 cfs @ 1.34 fps) RPBCWD - 10-YR 24-hr 10y 24hr Rainfall=4.27"Bongards_ProofofParking_06292017 Printed 6/29/2017Prepared by Microsoft Page 12HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Time span=5.00-240.00 hrs, dt=0.05 hrs, 4701 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=23,885 sf 0.80% Impervious Runoff Depth=2.27"Subcatchment DA-1: DA1-ToNorth (Overland) Flow Length=200' Slope=0.1000 '/' Tc=2.8 min CN=80 Runoff=2.57 cfs 0.104 af Runoff Area=9,275 sf 5.93% Impervious Runoff Depth=2.35"Subcatchment DA-2: DA2-ToSouth (Overland) Flow Length=225' Slope=0.0260 '/' Tc=5.8 min CN=81 Runoff=0.88 cfs 0.042 af Runoff Area=19,656 sf 98.07% Impervious Runoff Depth>4.01"Subcatchment DA-3a: DA3a-ToBMP Flow Length=200' Slope=0.0100 '/' Tc=4.2 min CN=98 Runoff=3.09 cfs 0.151 af Runoff Area=26,400 sf 82.80% Impervious Runoff Depth>3.70"Subcatchment DA-3b: DA3b-ToNorthwest Flow Length=150' Slope=0.0100 '/' Tc=3.9 min CN=95 Runoff=4.07 cfs 0.187 af Inflow=2.57 cfs 0.104 afReach 1R: To North Outflow=2.57 cfs 0.104 af Inflow=0.88 cfs 0.042 afReach 2R: To South Outflow=0.88 cfs 0.042 af Inflow=8.17 cfs 0.455 afReach 3R: Total Proposed Outflow=8.17 cfs 0.455 af Inflow=4.83 cfs 0.310 afReach 4R: To Northwest (pipe) Outflow=4.83 cfs 0.310 af Peak Elev=937.44' Storage=3,167 cf Inflow=3.09 cfs 0.151 afPond 12P: Underground treatment-10" pipe, 4" Outflow=1.07 cfs 0.123 af Total Runoff Area = 1.819 ac Runoff Volume = 0.483 af Average Runoff Depth = 3.19" 47.13% Pervious = 0.857 ac 52.87% Impervious = 0.961 ac RPBCWD - 10-YR 24-hr 10y 24hr Rainfall=4.27"Bongards_ProofofParking_06292017 Printed 6/29/2017Prepared by Microsoft Page 13HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment DA-1: DA1-ToNorth (Overland) [49] Hint: Tc<2dt may require smaller dt [73] Warning: Peak may fall outside time span Runoff =2.57 cfs @ 12.05 hrs, Volume=0.104 af, Depth=2.27" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - 10-YR 24-hr 10y 24hr Rainfall=4.27" Area (sf)CN Description 23,693 80 >75% Grass cover, Good, HSG D 192 98 Unconnected pavement, HSG D 23,885 80 Weighted Average 23,693 99.20% Pervious Area 192 0.80% Impervious Area 192 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 2.8 200 0.1000 1.20 Lag/CN Method, Summary for Subcatchment DA-2: DA2-ToSouth (Overland) [49] Hint: Tc<2dt may require smaller dt [73] Warning: Peak may fall outside time span Runoff =0.88 cfs @ 12.09 hrs, Volume=0.042 af, Depth=2.35" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - 10-YR 24-hr 10y 24hr Rainfall=4.27" Area (sf)CN Description *550 98 impervious 8,725 80 >75% Grass cover, Good, HSG D 9,275 81 Weighted Average 8,725 94.07% Pervious Area 550 5.93% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.8 225 0.0260 0.65 Lag/CN Method, Summary for Subcatchment DA-3a: DA3a-ToBMP [49] Hint: Tc<2dt may require smaller dt [73] Warning: Peak may fall outside time span Runoff =3.09 cfs @ 12.06 hrs, Volume=0.151 af, Depth>4.01" RPBCWD - 10-YR 24-hr 10y 24hr Rainfall=4.27"Bongards_ProofofParking_06292017 Printed 6/29/2017Prepared by Microsoft Page 14HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - 10-YR 24-hr 10y 24hr Rainfall=4.27" Area (sf)CN Description *19,277 98 impervious 379 80 >75% Grass cover, Good, HSG D 19,656 98 Weighted Average 379 1.93% Pervious Area 19,277 98.07% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 4.2 200 0.0100 0.80 Lag/CN Method, Summary for Subcatchment DA-3b: DA3b-ToNorthwest (Pipe) [49] Hint: Tc<2dt may require smaller dt [73] Warning: Peak may fall outside time span Runoff =4.07 cfs @ 12.06 hrs, Volume=0.187 af, Depth>3.70" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - 10-YR 24-hr 10y 24hr Rainfall=4.27" Area (sf)CN Description *21,859 98 impervious 3,317 80 >75% Grass cover, Good, HSG D *1,224 80 Pervious Pavers 26,400 95 Weighted Average 4,541 17.20% Pervious Area 21,859 82.80% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 3.9 150 0.0100 0.64 Lag/CN Method, Summary for Reach 1R: To North [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.548 ac,0.80% Impervious, Inflow Depth = 2.27" for 10y 24hr event Inflow =2.57 cfs @ 12.05 hrs, Volume=0.104 af Outflow =2.57 cfs @ 12.05 hrs, Volume=0.104 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - 10-YR 24-hr 10y 24hr Rainfall=4.27"Bongards_ProofofParking_06292017 Printed 6/29/2017Prepared by Microsoft Page 15HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Summary for Reach 2R: To South [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.213 ac,5.93% Impervious, Inflow Depth = 2.35" for 10y 24hr event Inflow =0.88 cfs @ 12.09 hrs, Volume=0.042 af Outflow =0.88 cfs @ 12.09 hrs, Volume=0.042 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Summary for Reach 3R: Total Proposed [40] Hint: Not Described (Outflow=Inflow) Inflow Area =1.819 ac,52.87% Impervious, Inflow Depth > 3.00" for 10y 24hr event Inflow =8.17 cfs @ 12.06 hrs, Volume=0.455 af Outflow =8.17 cfs @ 12.06 hrs, Volume=0.455 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Summary for Reach 4R: To Northwest (pipe) [40] Hint: Not Described (Outflow=Inflow) Inflow Area =1.057 ac,89.32% Impervious, Inflow Depth > 3.51" for 10y 24hr event Inflow =4.83 cfs @ 12.06 hrs, Volume=0.310 af Outflow =4.83 cfs @ 12.06 hrs, Volume=0.310 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Summary for Pond 12P: Underground treatment-10" pipe, 4" cover, minimum 440 LF, SA 6125 SF [82] Warning: Early inflow requires earlier time span Inflow Area =0.451 ac,98.07% Impervious, Inflow Depth > 4.01" for 10y 24hr event Inflow =3.09 cfs @ 12.06 hrs, Volume=0.151 af Outflow =1.07 cfs @ 12.21 hrs, Volume=0.123 af, Atten= 65%, Lag= 9.1 min Primary =1.07 cfs @ 12.21 hrs, Volume=0.123 af Routing by Stor-Ind method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Peak Elev= 937.44' @ 12.21 hrs Surf.Area= 6,104 sf Storage= 3,167 cf Plug-Flow detention time= 155.0 min calculated for 0.123 af (81% of inflow) Center-of-Mass det. time= 104.7 min ( 852.5 - 747.8 ) Volume Invert Avail.Storage Storage Description #1A 936.20'4,353 cf 145.33'W x 42.00'L x 1.83'H Field A 11,191 cf Overall - 309 cf Embedded = 10,882 cf x 40.0% Voids #2A 936.70'309 cf CPP 10 x 22 Inside #1 Inside= 10.0"W x 10.0"H => 0.70 sf x 20.00'L = 14.0 cf Outside= 12.0"W x 12.0"H => 0.70 sf x 20.00'L = 14.0 cf RPBCWD - 10-YR 24-hr 10y 24hr Rainfall=4.27"Bongards_ProofofParking_06292017 Printed 6/29/2017Prepared by Microsoft Page 16HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC 11 Rows of 2 Chambers 4,661 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 933.96'10.0" Round Culvert L= 16.0' CPP, end-section conforming to fill, Ke= 0.500 Inlet / Outlet Invert= 933.96' / 933.00' S= 0.0600 '/' Cc= 0.900 n= 0.010 PVC, smooth interior, Flow Area= 0.55 sf #2 Device 1 937.70'4.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) #3 Device 1 936.70'8.0" Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=1.06 cfs @ 12.21 hrs HW=937.43' (Free Discharge) 1=Culvert (Passes 1.06 cfs of 4.59 cfs potential flow) 2=Sharp-Crested Rectangular Weir ( Controls 0.00 cfs) 3=Orifice/Grate (Orifice Controls 1.06 cfs @ 3.05 fps) RPBCWD - 100-YR 24-hr 100y 24hr Rainfall=7.41"Bongards_ProofofParking_06292017 Printed 6/29/2017Prepared by Microsoft Page 17HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Time span=5.00-240.00 hrs, dt=0.05 hrs, 4701 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=23,885 sf 0.80% Impervious Runoff Depth=5.07"Subcatchment DA-1: DA1-ToNorth (Overland) Flow Length=200' Slope=0.1000 '/' Tc=2.8 min CN=80 Runoff=5.26 cfs 0.232 af Runoff Area=9,275 sf 5.93% Impervious Runoff Depth=5.19"Subcatchment DA-2: DA2-ToSouth (Overland) Flow Length=225' Slope=0.0260 '/' Tc=5.8 min CN=81 Runoff=1.78 cfs 0.092 af Runoff Area=19,656 sf 98.07% Impervious Runoff Depth>7.13"Subcatchment DA-3a: DA3a-ToBMP Flow Length=200' Slope=0.0100 '/' Tc=4.2 min CN=98 Runoff=5.00 cfs 0.268 af Runoff Area=26,400 sf 82.80% Impervious Runoff Depth>6.81"Subcatchment DA-3b: DA3b-ToNorthwest Flow Length=150' Slope=0.0100 '/' Tc=3.9 min CN=95 Runoff=6.73 cfs 0.344 af Inflow=5.26 cfs 0.232 afReach 1R: To North Outflow=5.26 cfs 0.232 af Inflow=1.78 cfs 0.092 afReach 2R: To South Outflow=1.78 cfs 0.092 af Inflow=14.92 cfs 0.908 afReach 3R: Total Proposed Outflow=14.92 cfs 0.908 af Inflow=8.13 cfs 0.584 afReach 4R: To Northwest (pipe) Outflow=8.13 cfs 0.584 af Peak Elev=937.89' Storage=4,317 cf Inflow=5.00 cfs 0.268 afPond 12P: Underground treatment-10" pipe, 4" Outflow=2.65 cfs 0.240 af Total Runoff Area = 1.819 ac Runoff Volume = 0.936 af Average Runoff Depth = 6.18" 47.13% Pervious = 0.857 ac 52.87% Impervious = 0.961 ac RPBCWD - 100-YR 24-hr 100y 24hr Rainfall=7.41"Bongards_ProofofParking_06292017 Printed 6/29/2017Prepared by Microsoft Page 18HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Summary for Subcatchment DA-1: DA1-ToNorth (Overland) [49] Hint: Tc<2dt may require smaller dt [73] Warning: Peak may fall outside time span Runoff =5.26 cfs @ 12.05 hrs, Volume=0.232 af, Depth=5.07" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - 100-YR 24-hr 100y 24hr Rainfall=7.41" Area (sf)CN Description 23,693 80 >75% Grass cover, Good, HSG D 192 98 Unconnected pavement, HSG D 23,885 80 Weighted Average 23,693 99.20% Pervious Area 192 0.80% Impervious Area 192 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 2.8 200 0.1000 1.20 Lag/CN Method, Summary for Subcatchment DA-2: DA2-ToSouth (Overland) [49] Hint: Tc<2dt may require smaller dt [73] Warning: Peak may fall outside time span Runoff =1.78 cfs @ 12.09 hrs, Volume=0.092 af, Depth=5.19" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - 100-YR 24-hr 100y 24hr Rainfall=7.41" Area (sf)CN Description *550 98 impervious 8,725 80 >75% Grass cover, Good, HSG D 9,275 81 Weighted Average 8,725 94.07% Pervious Area 550 5.93% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 5.8 225 0.0260 0.65 Lag/CN Method, Summary for Subcatchment DA-3a: DA3a-ToBMP [49] Hint: Tc<2dt may require smaller dt [73] Warning: Peak may fall outside time span Runoff =5.00 cfs @ 12.06 hrs, Volume=0.268 af, Depth>7.13" RPBCWD - 100-YR 24-hr 100y 24hr Rainfall=7.41"Bongards_ProofofParking_06292017 Printed 6/29/2017Prepared by Microsoft Page 19HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - 100-YR 24-hr 100y 24hr Rainfall=7.41" Area (sf)CN Description *19,277 98 impervious 379 80 >75% Grass cover, Good, HSG D 19,656 98 Weighted Average 379 1.93% Pervious Area 19,277 98.07% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 4.2 200 0.0100 0.80 Lag/CN Method, Summary for Subcatchment DA-3b: DA3b-ToNorthwest (Pipe) [49] Hint: Tc<2dt may require smaller dt [73] Warning: Peak may fall outside time span Runoff =6.73 cfs @ 12.06 hrs, Volume=0.344 af, Depth>6.81" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - 100-YR 24-hr 100y 24hr Rainfall=7.41" Area (sf)CN Description *21,859 98 impervious 3,317 80 >75% Grass cover, Good, HSG D *1,224 80 Pervious Pavers 26,400 95 Weighted Average 4,541 17.20% Pervious Area 21,859 82.80% Impervious Area Tc Length Slope Velocity Capacity Description (min)(feet)(ft/ft)(ft/sec)(cfs) 3.9 150 0.0100 0.64 Lag/CN Method, Summary for Reach 1R: To North [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.548 ac,0.80% Impervious, Inflow Depth = 5.07" for 100y 24hr event Inflow =5.26 cfs @ 12.05 hrs, Volume=0.232 af Outflow =5.26 cfs @ 12.05 hrs, Volume=0.232 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs RPBCWD - 100-YR 24-hr 100y 24hr Rainfall=7.41"Bongards_ProofofParking_06292017 Printed 6/29/2017Prepared by Microsoft Page 20HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC Summary for Reach 2R: To South [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.213 ac,5.93% Impervious, Inflow Depth = 5.19" for 100y 24hr event Inflow =1.78 cfs @ 12.09 hrs, Volume=0.092 af Outflow =1.78 cfs @ 12.09 hrs, Volume=0.092 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Summary for Reach 3R: Total Proposed [40] Hint: Not Described (Outflow=Inflow) Inflow Area =1.819 ac,52.87% Impervious, Inflow Depth > 5.99" for 100y 24hr event Inflow =14.92 cfs @ 12.06 hrs, Volume=0.908 af Outflow =14.92 cfs @ 12.06 hrs, Volume=0.908 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Summary for Reach 4R: To Northwest (pipe) [40] Hint: Not Described (Outflow=Inflow) Inflow Area =1.057 ac,89.32% Impervious, Inflow Depth > 6.63" for 100y 24hr event Inflow =8.13 cfs @ 12.06 hrs, Volume=0.584 af Outflow =8.13 cfs @ 12.06 hrs, Volume=0.584 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Summary for Pond 12P: Underground treatment-10" pipe, 4" cover, minimum 440 LF, SA 6125 SF [82] Warning: Early inflow requires earlier time span Inflow Area =0.451 ac,98.07% Impervious, Inflow Depth > 7.13" for 100y 24hr event Inflow =5.00 cfs @ 12.06 hrs, Volume=0.268 af Outflow =2.65 cfs @ 12.16 hrs, Volume=0.240 af, Atten= 47%, Lag= 5.9 min Primary =2.65 cfs @ 12.16 hrs, Volume=0.240 af Routing by Stor-Ind method, Time Span= 5.00-240.00 hrs, dt= 0.05 hrs Peak Elev= 937.89' @ 12.16 hrs Surf.Area= 6,104 sf Storage= 4,317 cf Plug-Flow detention time= 102.6 min calculated for 0.240 af (90% of inflow) Center-of-Mass det. time= 71.6 min ( 811.2 - 739.7 ) Volume Invert Avail.Storage Storage Description #1A 936.20'4,353 cf 145.33'W x 42.00'L x 1.83'H Field A 11,191 cf Overall - 309 cf Embedded = 10,882 cf x 40.0% Voids #2A 936.70'309 cf CPP 10 x 22 Inside #1 Inside= 10.0"W x 10.0"H => 0.70 sf x 20.00'L = 14.0 cf Outside= 12.0"W x 12.0"H => 0.70 sf x 20.00'L = 14.0 cf RPBCWD - 100-YR 24-hr 100y 24hr Rainfall=7.41"Bongards_ProofofParking_06292017 Printed 6/29/2017Prepared by Microsoft Page 21HydroCAD® 10.00-19 s/n 01489 © 2016 HydroCAD Software Solutions LLC 11 Rows of 2 Chambers 4,661 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 933.96'10.0" Round Culvert L= 16.0' CPP, end-section conforming to fill, Ke= 0.500 Inlet / Outlet Invert= 933.96' / 933.00' S= 0.0600 '/' Cc= 0.900 n= 0.010 PVC, smooth interior, Flow Area= 0.55 sf #2 Device 1 937.70'4.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) #3 Device 1 936.70'8.0" Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=2.59 cfs @ 12.16 hrs HW=937.89' (Free Discharge) 1=Culvert (Passes 2.59 cfs of 4.92 cfs potential flow) 2=Sharp-Crested Rectangular Weir (Weir Controls 1.04 cfs @ 1.41 fps) 3=Orifice/Grate (Orifice Controls 1.55 cfs @ 4.45 fps) 06 /30/2017 BONGARDS EXPANSION: STORMWATER MANAGEMEN T PLAN C APPENDIX C : GEOTECHNICAL REPORT GEOTECHNICAL EXPLORATION AND ENGINEERING REVIEW Bongards Facilty Expansion Chanhassen Minnesota NTI Project No. 16.61712.100 Prepared For: Solution Blue, Inc. 318 Cedar Street St. Paul, Minnesota 55101 October 13, 2016 Solution Blue, Inc. 318 Cedar Street Saint Paul, Minnesota 55101 Attn: Mitchell Cookas Subject: Geotechnical Exploration and Engineering Review Bongards Facilty Expansion Chanhassen, Minnesota NTI Project No. 16.61712.100 Dear Mr. Cookas, In accordance to your request and subsequent authorization, Northern Technologies, LLC (NTI) conducted a Geotechnical Exploration for the above referenced project. Our services included advancement of exploration borings and preparation of an engineering report with recommendations developed from our geotechnical services. Our work was performed in general accordance with our proposal of dated September 20, 2016. Soil samples obtained at the site will be held for 60 days at which time they will be discarded. Please advise us in writing if you wish to have us retain them for a longer period. You will be assessed an additional fee if soil samples are retained beyond 60 days. We appreciate the opportunity to have been of service on this project. If there are any questions regarding the soils explored or our review and recommendations, please contact us at your convenience at (763) 433-9175. Northern Technologies, LLC Steven D. Gerber, P.E. Senior Engineer Debra A. Schroeder, P.E. Senior Engineer Bongards Facilty Expansion Chanhassen, Minnesota NTI Project No. 16.61712.100 Contents 1.0 EXECUTIVE SUMMARY ......................................................................................................................... 1 2.0 INTRODUCTION .................................................................................................................................... 2 2.1 Site / Project Description ....................................................................................................................... 2 2.2 Scope of Services .................................................................................................................................... 2 3.0 EXPLORATION PROGRAM RESULTS ...................................................................................................... 3 3.1 Exploration Scope .................................................................................................................................. 3 3.2 Subsurface Conditions ........................................................................................................................... 3 3.3 Groundwater Conditions ........................................................................................................................ 3 3.4 Laboratory Test Program ....................................................................................................................... 4 4.0 ENGINEERING REVIEW AND RECOMMENDATIONS .............................................................................. 4 4.1 Project Scope ......................................................................................................................................... 4 4.2 Site Preparation ..................................................................................................................................... 5 4.3 Shallow Foundations .............................................................................................................................. 7 4.4 Bearing Factor of Safety and Estimate of Settlement ............................................................................ 8 4.5 Subsurface Drainage .............................................................................................................................. 8 4.6 Utilities ................................................................................................................................................... 9 4.7 Slab-on-Grade Floors ............................................................................................................................. 9 4.8 Surface Drainage ................................................................................................................................. 10 4.9 Pavement Construction ....................................................................................................................... 10 4.10 Stormwater Infiltration ........................................................................................................................ 12 5.0 CONSTRUCTION CONSIDERATIONS .................................................................................................... 13 5.1 Frost Considerations ............................................................................................................................ 13 5.2 Excavation Stability ............................................................................................................................. 13 5.3 Engineered Fill & Winter Construction................................................................................................. 13 6.0 CLOSURE ............................................................................................................................................ 14 Page 1 of 14 GEOTECHNICAL EXPLORATION AND ENGINEERING REVIEW Bongards Facilty Expansion NTI Project No. 16.61712.100 1.0 EXECUTIVE SUMMARY We briefly summarize below our geotechnical recommendations for the proposed project. The summary must be read in complete context with our report. • The soil borings drilled for this project encountered 4 ½ to 5 feet of existing fill over rather stiff to stiff glacial till soils. While the existing fill soils are considered unsuitable for foundation support, their removal would generally be incidental to the excavation required for the below grade level. • We conclude you may support the proposed structure upon standard perimeter strip and spread column footings on competent, non-organic natural soil(s) or engineered fill, as recommended within our report. • Building linear strip footings and interior column footings (if required) may be proportioned using the maximum net allowable soil bearing pressures of 3,500 pounds per square foot (psf). The onsite soils appear to be suitable for reuse as structural fill, although there may portions of the existing fill materials that contain debris or other unsuitable material that would not be suitable for reuse. • Measurable groundwater was encountered at depths ranging between approximately 2 and 20 ½ feet below the existing grade. The groundwater variance is due to the general impermeability of the onsite clay laden soils and the occasional sand seams that contain likely perched groundwater. • Overall, the site soils are conducive to movement of groundwater both laterally and vertically over time. The moisture content of such soils can vary annually and per recent precipitation. Such soils and other regional dependent conditions may produce groundwater entry of project excavations. We direct your attention to other report sections and appendices attachments concerning groundwater issues and subsurface drainage. Bongards Facilty Expansion Chanhassen, Minnesota NTI Project No. 16.61712.100 Page 2 of 14 2.0 INTRODUCTION 2.1 Site / Project Description The proposed Bongards Facilty Expansion project is to be constructed as defined within Table 1. Table 1: Project & Site Description Item Description Building Type Single story, slab on grade, warehouse/ commercial facility. First Floor Elevation To match the existing slab Maximum Proposed Change in Site Elevation Within 3 feet of existing site grades. Site Description Location of Project Bongards Facilty Expansion in Chanhassen, Minnesota Existing Land Use / Improvements to Parcel Surface level parking lot Current Ground Cover Bituminous pavement Topography at Site There is about 6 feet of grade change across the site. 2.2 Scope of Services The purpose of this report is to present a summary of our geotechnical exploration and provide generalized opinions and recommendations regarding the soil conditions and design parameters for founding of the project. Our “scope of services” was limited to the following: 1. Explore the project subsurface by means of eight standard penetration borings extending to maximum depths of approximately 20 feet below existing grade, and conduct laboratory test(s) on representative samples for characterizing the index and engineering properties of soils strata at site. 2. Prepare a report presenting our findings from our field exploration, laboratory testing, and engineering recommendations for foundation types, footing depths, allowable bearing capacity, estimated settlements, floor slab support, excavation, engineered fill, backfill, compaction and potential construction difficulties related to excavation, backfilling and drainage, pavement design, and estimated stormwater infiltration rates. Bongards Facilty Expansion Chanhassen, Minnesota NTI Project No. 16.61712.100 Page 3 of 14 3.0 EXPLORATION PROGRAM RESULTS 3.1 Exploration Scope Site geotechnical drilling occurred on October 7, 2016 with individual borings advanced at approximate locations as presented on the diagram within the appendices. NTI located the borings relative to existing site features. The boring elevations were estimated using a Trimble GeoXH 6000 and are relative to the NAD 1983 CORS 1996 datum. Please refer to the Boring Location Diagram in Appendix C for additional details. 3.2 Subsurface Conditions Please refer to the boring logs within the appendices for a detailed description and depths of stratum at each boring. The boreholes were backfilled with auger cuttings or were abandoned using high solids bentonite or neat cement grout as per appropriate local and state statutes. Minor settlement of the boreholes will occur. The Owner is responsible for final closure of the boreholes. Based on results of the current geotechnical exploration, Table 2 provides a general depiction of subsurface conditions at the project site. Additional comment on the evaluation of recovered soil samples is presented within the report attachments. Table 2: Typical Subsurface Stratigraphy at Project Site Note 1 Stratum Depth to Base of Stratum below existing grade Material Description Notes Surface 4 to 8 inches Apparent Topsoil 16 Inches in boring SB-7. Topsoil classification by visual observation only and not intended to confer conformance with DOT or other municipal standards. Undocumented Fill 4 ½ to 5 feet Sandy lean clay (CL), occasional organic matter The undocumented fill was variably compacted. Glacial Deposits Termination depths of the borings at approximately 20 feet. Sandy lean clay (CL) and clayey sand (SC) Occasional sand and silt seams; Occasional cobbles Note 1 Table summary is a generalization of subsurface conditions and may not reflect variation in subsurface strata occurring on site. The general geologic origin of retained soil samples is listed on the boring logs. 3.3 Groundwater Conditions Groundwater was observed at depths ranging between 2 and 20 ½ feet at the time of drilling. Groundwater should be expected to be encountered within sand and silt seams that are above, or surrounded by, clay laden glacial till soils. Due to the relatively impermeable nature of most of the Bongards Facilty Expansion Chanhassen, Minnesota NTI Project No. 16.61712.100 Page 4 of 14 onsite soils, our borings may not have been open long enough to reach equilibrium with the surrounding groundwater surface. Long term observations, such as with piezometers, would be required to obtain a more precise groundwater elevation reading. Overall, the site soils are conducive to movement of groundwater both laterally and vertically over time. The moisture content of such soils can vary annually and per recent precipitation. Such soils and other regional dependent conditions may produce groundwater entry of project excavations. We direct your attention to other report sections and appendices attachments concerning groundwater issues and subsurface drainage. 3.4 Laboratory Test Program Our analysis and recommendations of this report are based upon our interpretation of the standard penetration resistance determined while sampling soils, laboratory test results and experience with similar soils from other sites near the project. The results of such tests are summarized on the boring logs or attached test forms. 4.0 ENGINEERING REVIEW AND RECOMMENDATIONS The following recommendations are based on our present knowledge of the project. We ask that you or your design team notify us immediately if significant changes are made to project size, location or design as we would need to review our current recommendations and provide modified or different recommendations with respect to such change(s). 4.1 Project Scope We understand the proposed structure will include concrete foundation walls and footings for support of above grade construction. NTI’s assumed foundation loads and change in grade is summarized within Table 3. Our assessment of project soils, opinions, and report recommendations are based directly on application of estimated structural loads to site soils. Bongards Facilty Expansion Chanhassen, Minnesota NTI Project No. 16.61712.100 Page 5 of 14 Table 3: Foundation Loads / Change in Grade / Footing Elevation Building Element Load / Condition Perimeter Strip Footings 4 kips per lineal foot or less Interior Strip Footings 4 kips per lineal foot or less Isolated Interior Column Footings 150 kips or less Exterior Column Footings 150 kips or less Change in Overall Site Grade (from original ground surface) 5 feet or less Basement Excavation (from final grade) None Anticipated Free standing retaining walls None Anticipated 4.2 Site Preparation Project construction, as proposed, will site grading, and removal of all existing underground utilities from within the proposed building pad (if encountered). The undocumented, previously placed fill encountered in the soil borings is not considered suitable for direct support of the foundations. If suitable documentation is made available to NTI that demonstrates that the existing fill is engineered, it may be suitable for direct support of the proposed foundations. Further review and evaluation by NTI would be required for this scenario prior to modifying the recommendations herein. NTI recommends that all existing topsoil, buried organic materials, and any other manmade structures that are encountered be removed from within the building pad. In addition, NTI recommends that all previously placed undocumented fill be removed from below the foundation elements. Dependent upon the Owner’s tolerance for risk of future differential settlement, a complete soil correction may be required below the floor slab as well. Please refer to the floor slab recommendations below for more information. We anticipate that a portion of the previously placed fill soil would be excavated incidentally to attain the proposed frost depth foundation elevation. We recommend that all earthwork improvements and excavations be oversized where fill materials are placed below foundations. The minimum excavation oversize should extend per the requirements outlined in Appendix B. Table 4 provides a summary of excavation necessary to remove unsuitable materials at respective borings. Bongards Facilty Expansion Chanhassen, Minnesota NTI Project No. 16.61712.100 Page 6 of 14 Table 4: Summary of Soil Correction / Excavation Boring Number Existing Ground Elevation (feet) Depth (feet) Unsuitable Soil / Material Estimated Excavation Elevation (feet) SB-1 939 5 Topsoil / Undocumented Fill 934 SB-2 942 4.5 Topsoil / Undocumented Fill 937.5 SB-3 941 5 Topsoil / Undocumented Fill 936 SB-4 941 5 Topsoil / Undocumented Fill 936 SB-5 942.5 4.5 Topsoil / Undocumented Fill 938 SB-6* 942.5 4.5 Topsoil / Undocumented Fill 938.0 SB-7* 941.5 4.5 Topsoil / Undocumented Fill 937 SB-8* 941.5 4.5 Topsoil / Undocumented Fill 937 * Soil borings completed within proposed paved areas will not necessarily require full depth corrections. They are included within this table for general reference only. The Geotechnical Engineer of Record or their designated representative should review project excavations to verify removal of unsuitable material(s) and adequate bearing support of exposed soils. All such observations should occur prior to the placement of engineering fill, or construction of footings and floor slabs. We recommend that native soils at the exposed grade (i.e. base of excavations) be compacted until such materials achieve no less than 98% of the standard proctor maximum dry density (ASTM: D 698-96). Sidewalls should be benched or sloped to provide safe working conditions and stability for engineered fill placement. Any oversizing that is required should be performed in accordance with the diagram and table included in Appendix A. Engineered fill should consist of onsite or imported material with 100 percent passing the 1½ inch sieve and a Liquid Limit less than 40.. Portions of the existing on-site granular undocumented fill soils have the potential to be re-used as engineered fill for preparation of the building pad when such soils are conditioned and placed as presented within this report. However, due to the undocumented nature of the fill soils there is the potential that zones of organic or debris laden soils may be encountered as well. Any organic or debris laden soils will need to be sorted and are not considered to be suitable for reuse. Considering that the composition and compaction effort of existing fill soils are not documented, the prediction of the percent of re-usable material is difficult. In addition, the exact delineation of native versus undocumented fill, in cobble and gravel laden granular soils, in particular, are difficult due to the limited sample size and soil disturbance due the sampling technique. For this reason, the design team should be aware that there is the potential that there may be some variation in the depth of fill encountered during site excavations as compared to the boring logs. If the Owner wishes to refine the understanding of the composition and depths of the undocumented fill soils across the site, NTI suggests that a series of test pits be advanced at the site prior to construction. Bongards Facilty Expansion Chanhassen, Minnesota NTI Project No. 16.61712.100 Page 7 of 14 NTI can also review documentation of the existing fill, if provided, which would also help refine the understanding of the fill materials. Placement of structural fill should be observed and tested by an experienced technician or engineer to criteria described in Appendix B. Structural fill with moisture contents outside of the recommended range should be conditioned (dried or wetted) as appropriate prior to placement. Engineered fill for site corrective earthwork and for support of project footings should be tempered for moisture content and placed and compacted as outlined Appendix B. 4.3 Shallow Foundations The following bearing recommendations are based on our understanding of the project. You should notify us of any changes made to the project size, location, design or site grades so we can assess how such changes impact our recommendations. We assume foundation elements will impose maximum vertical loads as previously noted within this report. In our opinion, you may support the proposed structure by founding strip footings and interior column footings on competent, non-organic native soils, or engineered fill, providing such construction complies with the criteria established within this report. Design of footings may be based on the Table 4 maximum net allowable soil bearing pressures. Table 4: Recommended Maximum Net Allowable Soil Bearing Pressure1 - Conventional Shallow Foundation Construction Location Criteria Perimeter Strip Footings, Perimeter Columns: Perimeter strip footings and perimeter column footing supported on documented fill or competent native soils below depth of frost penetration. Interior Strip Footings: Interior strip footings supported on documented fill or competent native soils at a depth that provides no less than 6 inches of clearance between the top of footing and underside of floor slab (for sand cushion). Interior Column Footings: Supported on documented fill or competent native soils at a depth that provides no less than 6 inches of clearance between the top of footing and underside of floor slab (for sand cushion). Maximum 3,500 psf on native sand (All foundations) 1. Maximum net allowable soil bearing pressure recommendations predicated on footing design and construction complying with recommendations presented within this report. To minimize local failure of supporting soils, it is our opinion footing construction should comply with the International Building Code (IBC) requirements. We recommend that the base of all foundation subgrades be surface compacted prior to the placement of concrete or fill. Foundations in unheated appurtenant areas, such as stoops and canopies, should be based at least 5 feet below the proposed finished grade for frost protection. Footings below structures anticipated to be heated (greater than 60 degrees F) in winter should be constructed at least 3.5 feet below proposed finished grade. Bongards Facilty Expansion Chanhassen, Minnesota NTI Project No. 16.61712.100 Page 8 of 14 Continuous strip footings under bearing walls should be at least 1 foot wider than the walls they support. Interior footings should be based at least 2.0 feet below design floor elevation. 4.4 Bearing Factor of Safety and Estimate of Settlement We estimate native soils and properly placed engineered fill soils will provide a nominal 3 factor of safety against localized bearing failure when construction complies with report criteria and recommendations, and you design structure footings using the Table 5 maximum net allowable soil bearing recommendation(s). We estimate that footings loaded per report recommendations may experience long term, total settlement of approximately 1/2 to 1 inch. Differential settlement will be on the order of 25 to 50 percent of total settlement. Generally, the greatest differential settlement occurs between lightly loaded and heavily loaded footings, particularly if heavily loaded footings are located adjacent to lightly loaded strip footings. Most of the settlement will occur on first loading, as the structure is erected. Furthermore, total and differential movement of footings and floor slabs could be significantly greater than the above estimates if you support construction on frozen soils. The moisture content of the bearing soils significantly changes from in-situ conditions when snow or ice lenses are incorporated into site earthwork. Most of the settlement will occur on first loading, as the structure is erected. It should be understood that the settlement in the existing structure will have already occurred, while the settlement in the addition will occur during and after construction. Consequently, the settlement between the existing building and the addition should be assumed to be differential settlement, unless otherwise accommodated by structural design. In order to help prevent the overlap of stresses and the resulting potential for induced settlement in the existing structure, we recommend that new foundations be placed at least one footing width horizontally from the existing structure. 4.5 Subsurface Drainage NTI considers the installation of a subsurface drain system at the interior base of foundation walls to be a preferred practice of construction. The subsurface drain system will help to limit moisture accumulation within granular soils placed below interior floors. As a general guideline, subsurface drainage consists of a geotextile and coarse drainage encased slotted or perforated pipe extending to sump basin(s) We recommend that exterior drainage be separated from interior drainage to reduce risk of cross flow and moisture infiltration below structure interior. The project Architect and/or Structural Engineer of Record should determine actual need for subsurface drainage. Bongards Facilty Expansion Chanhassen, Minnesota NTI Project No. 16.61712.100 Page 9 of 14 4.6 Utilities Utility trenches should be backfilled in 6-inch maximum depth loose lifts. It is especially important that you compact trench backfill of underground utilities to minimize future settlement of green space and pavement areas. Please refer to Appendix B for compaction specifications. The stability of embankments along utility excavations is dependent on soil strength, site geometry, moisture content, and any surcharge load for excavated soils and equipment. Cautionary comment on excavation stability is provided within other report sections. We herein note that the Contractor is solely responsible for assessing the stability of and executing underground utility and project excavations using safe methods. Contractor is also responsible for naming the “competent individual” as per Subpart P of 29 CFR 1926.6 (Federal Register - OSHA). 4.7 Slab-on-Grade Floors Option 1 (Floor Slab Supported On Existing Undocumented Fill) For this alternative the Owner must be willing to accept some risk of future settlement within the floor slab. For Option 1, the existing non-organic debris free undocumented fill soils in the floor slab area would be surface compacted with shallow corrections performed in areas that exhibit instability or where organics are encountered. The floor slab would then be constructed over the surface-compacted existing non organic, debris-free undocumented fill soils. This option will provide less uniform subgrade support. This option also has the potential for increased distress within the floor slab. If this option is selected the modulus of subgrade reaction (k) design value should be reduced to 125 pci (pounds per square inch per inch of depth). The risk of differential settlements in the slab could be reduced if the upper 1 foot, or more, of the slab subgrade is over- excavated and replaced with properly compacted granular backfill. Option 2 (Floor Slab Supported On Non-Organic or Engineered Fill) If the Owner is unwilling to accept the risks associated with Option 1 then the floor slabs should be constructed directly over documented engineered fill or non-organic, competent native soil as described in the Site Preparation section. For this option, the design of the floor slab may be based on an estimated modulus of subgrade reaction (k) of 175 pci. Option 2 will be based on a more uniform subgrade compared to the existing undocumented fill. The Following Applies to Both Options The final 6 inches of fill below the concrete floor slabs should consist of pit run or processed sand (sand cushion) with 100 percent material passing the 1 inch, no more than 40 percent passing the No. 40 sieve and no more than 5 percent material passing the No. 200 U.S. Sieve. The moisture content of the sand cushion should be within plus or minus 2 percent of the optimum moisture content determined by the standard Proctor test. All interior at-grade floors with impervious or near impervious surfacing such as, but not limited to, paint, hardening agent, vinyl tile, ceramic tile, or wood flooring, should include provision for installation Bongards Facilty Expansion Chanhassen, Minnesota NTI Project No. 16.61712.100 Page 10 of 14 of a vapor barrier system. Historically, vapor barrier systems can consist of many different types of synthetic membrane, and can be placed either below sand cushion materials or at the underside of the concrete floor. All such issues are contentious and have both positive and negative aspects associated with long term performance of the floor. Overall, we recommend you install some form of vapor barrier below the project floor [for at-grade and basement construction, as appropriate]. We recommend that you isolate floor slabs from other building components by placement of a nominal ½ inch thick expansion joint between the floor and walls, and/or columns. This construction must also apply a compatible sealant after curing of the floor slab to reduce moisture penetration though the expansion joint. As a minimum, you should install a bond breaker to isolate and reduce binding of building components. 4.8 Surface Drainage You should maintain positive drainage during and after construction of project and eliminate ponding of water on site soils. We recommend that you include provisions within construction documents for positive drainage of site. You should install sumps at critical areas around project excavations to assist in removal of seepage and runoff from site. We recommend that sidewalks, curbing, pavements, and green space be designed to direct drainage away from the structure. We recommend that you provide a 5 percent gradient within 10 feet of building for drainage from lawn, and 2 percent minimum gradient from building for drainage of sidewalks / pavements. All pavements should drain to on-site storm collection, municipal collection system, or roadside ditching. Roof runoff should be directed away from building by a system of interior roof and scupper drains, or rain gutters, down spouts and splash pads. It is our opinion interior roof drains plumbed directly to the storm water piping system provide the most favorable method of conveying drainage from the roof as interior drains do not freeze or discharge runoff onto exterior sidewalks and pavements. 4.9 Pavement Construction We assume project traffic will be separated into two distinct classes; heavy duty traffic comprised of refuse trucks and occasional delivery trucks and alternatively light duty traffic which would be comprised primarily of passenger vehicles. Our pavement recommendations are predicated on separation of this traffic. The resulting subgrade following site grading should first be scarified and re-compacted to a depth of 12 inches. A proofroll test should then be performed to determine soft or unstable subgrade areas. If rutting or localized unstable subgrade areas are observed, those areas should be subcut, moisture- conditioned, and re-compacted or removed to a stable depth. Excavations for soil corrections (if any) in paved areas should allow for a 2 foot oversize beyond the edges of the pavement. The proofroll should be performed with a tandem axle dump truck loaded to gross capacity (at least 20 tons). Acceptance criteria of the proofroll shall be limited to rut formation no more than one inch (1”) Bongards Facilty Expansion Chanhassen, Minnesota NTI Project No. 16.61712.100 Page 11 of 14 depth (front or rear axles) and no pumping (rolling) observed during the visual inspection. Proofroll tests should be observed by an experienced technician or geotechnical engineer prior to placement of the aggregate base course to verify the subgrade will provide adequate pavement support. Individual lifts of engineered fill in proposed paved areas should be tempered for moisture content, placed and compacted as listed in the Compaction Guidelines table in Appendix B. If fill is required in paved areas, we recommend that it consist of soils similar in composition to the existing subgrade soils. If clean sand materials are utilized as engineered fill in the areas where clay based soils were encountered, they will need to be adequately drained as to not create a “bathtub” effect overlying the clay based soils. If not adequately drained there is the potential that groundwater may collect within the void spaces of the sand and result in vertical movements during periods of freeze/thaw. We estimate that a properly prepared subgrade would have an average stabilometer R-value of 20. For a 20-year design pavement life and light commercial traffic volumes, Table 5 presents our thickness recommendations for flexible (bituminous) pavement. Table 5: Recommended Flexible Pavement Thickness Design Alternative Pavement Section Light Duty (Parking Stalls) Heavy Duty (Drive Lanes / Truck Areas) Bituminous Wear Course (inches) 1.5 2.0 Bituminous Base Course (inches) 2.0 2.5 Class 5 or 7 Aggregate Base (inches) 6.0 8.0 We recommend rigid Portland cement concrete pavements be constructed at driveway aprons, trash enclosures and other areas where point loads and turning stresses are more likely to damage the pavement. Based on the performance of concrete pavements at similar sites, we recommend the concrete pavement design alternative listed in Table 6. Table 6: Recommended Rigid Pavement Thickness Design Alternative Pavement Section Heavy Duty (Drive Lanes / Truck Areas) Static Loading Areas (Dumpsters) Unreinforced Concrete (inches) 6.0 7.0 Class 5 or 7 Aggregate Base (inches) 6.0 6.0 Permeable pavements would generally be constructed for temporary storage rather more than infiltration due to the low permeability of the soil. We recommend that a MnDOT separation geotextile be placed between the reservoir layer and the surrounding subgrade soils. The owner should be aware that winter sanding can significantly impact the performance of the pervious pavement. Vacuum cleaning of the pavement is recommended to be performed at least twice annually. Permeable Bongards Facilty Expansion Chanhassen, Minnesota NTI Project No. 16.61712.100 Page 12 of 14 pavement sections are provided below in Table 7. The pavement should be drained to prevent the stored water from freezing. Pavement Section Pervious Concrete Porous Bituminous Precast Pavers Surface (inches) 5.5 3.0 3.0 Bedding layer (inches) NA 1 (57 stone) 2 (8 stone) Reservoir Layer (inches)1 36 (57 stone) 36 (2, 3, or 5 stone) 2 inches (57 stone) over 36 inches (2,3, or 4 stone) 1. Reservoir layer may need to be thicker for hydraulics. Reservoir stone should be of an igneous or metamorphic source, such as granite, basalt, or gabbro. The soils on this site are quite susceptible to loss of strength when wet under dynamic loading conditions. The above pavement recommendations assume the subgrade soils and aggregate section below paved surfaces will drain to subsurface piping for eventual discharge into storm sewer, or above grade to ditching, or similar acceptable systems. Lack of surface and subsurface drainage will significantly reduce the capacity and longevity of the pavement systems indicated above. The recommended pavement sections are based on the post construction end use of the pavements. Loads during construction may exceed these conditions. We recommend that a proofroll be performed immediately before the placement of pavements, especially those exposed to precipitation. We recommend pavements receive annual maintenance, as a minimum, to correct damages to the pavement structure, clean and infill cracks which develop, and repair or resurface areas which exhibit reduced subgrade performance. The lack of maintenance can lead to moisture infiltration of the pavement structure and softening of the subgrade soils. This, in turn, can degrade the performance of the pavement system and result in poorly performing pavements with shortened life expectancy. 4.10 Stormwater Infiltration Table 8 provides an estimate of the infiltration rates for the soils encountered by our geotechnical exploration program. Table 8: Estimated Infiltration Rates for Subsurface Soil at Project Note 1 Soil Type Estimated Infiltration Rate (inches / hr.) Lean Clay (CL) 0.06 Clayey Sand (SC) 0.06 Note 1 All findings are approximate based on correlation of on-site soils to the Minnesota Stormwater Manual, or other published literature. We recommend further assessment of soil infiltration rate using “Double-Ring Infiltrometer” evaluation, or other similar approved methods. Bongards Facilty Expansion Chanhassen, Minnesota NTI Project No. 16.61712.100 Page 13 of 14 5.0 CONSTRUCTION CONSIDERATIONS 5.1 Frost Considerations The sandy lean clay soils on this site are frost susceptible. Small amounts of groundwater, or infiltrated surface water, can be detrimental to the performance of the slabs and pavements. Exterior slabs and pavements should be expected to heave. If frost action needs to be eliminated in critical areas, then we recommend the use of structurally supported exterior slabs (e.g., as structural stoops in front of building doors), as is common practice in the state of Minnesota. It is our opinion that placing non-frost susceptible material in large areas under exterior pavements and sidewalks would be exceedingly expensive and an unusual design and construction procedure in Minnesota. A transition area between structurally supported slabs or non-frost susceptible materials should be constructed at a 3H:1V back slope to reduce the potential differential frost movements in the slabs or pavements. Draintile should be installed around the foundation perimeter and finger drains should be installed about catch basins and across low points in the pavement grades. Non-frost susceptible fill should consist of sand or gravel with less than 5 percent material passing the No. 200 sieve, and at least 50 percent retained on the No. 40 sieve. 5.2 Excavation Stability Excavation depth and sidewall inclination should not exceed those specified in local, state or federal regulations. Excavations may need to be widened and sloped, or temporarily braced, to maintain or develop a safe work environment. Also, contractors should comply with local, state, and federal safety regulations including current OSHA excavation and trench safety standards. Temporary shoring must be designed in accordance with applicable regulatory requirements. 5.3 Engineered Fill & Winter Construction The Geotechnical Engineer of Record or their designated representative should observe and evaluate excavations to verify removal of uncontrolled fills, topsoil and/or unsuitable material(s), and adequacy of bearing support of exposed soils. Such observation should occur prior to construction of foundations or placement of engineered fill supporting excavations. Engineered fill should be approved by the Geotechnical Engineer of Record prior to placement. In addition, the engineered fill should be tempered for correct moisture content and then place and compact individual lifts of engineered fill to criteria established within the appendices attachment. Frozen soil should never be used as engineered fill or backfill nor should you support foundations on frozen soils. Moisture freezing within the soil matrix of fine grained and/or cohesive soils produces ice lenses. Such soils gain moisture from capillary action and, with continued growth, heave with formation of ice lenses within the soil matrix. Foundations constructed on frozen soils have the potential to settle once ice lenses thaw. You should protect excavations and foundations from freezing conditions or accumulation of snow, and remove frozen soils, snow, and ice from within excavations, fill section or from below proposed Bongards Facilty Expansion Chanhassen, Minnesota NTI Project No. 16.61712.100 Page 14 of 14 foundations. Replacement soils should consist of similar materials as those removed from the excavation with moisture content, placement and compaction conforming to report criteria. 6.0 CLOSURE As the widely spaced, small diameter borings provide only a limited amount of data regarding the existing fill, the existing fill may contain soft zones, debris or significantly greater amounts of unsuitable materials than could be reasonably inferred from the boring information. Unsuitable materials may not be discovered during construction and may remain buried within the fill below the slabs and pavements, resulting in greater than anticipated settlements of the slabs and pavements. These risks cannot be eliminated without completely removing the fill, but can be reduced by thorough exploration and testing during site preparation and construction. Our conclusions and recommendations are predicated on observation and testing of the earthwork directed by Geotechnical Engineer of Record. Our opinions are based on data assumed representative of the site. However, the area coverage of borings in relation to the entire project is very small. For this and other reasons, we do not warrant conditions below the depth of our borings, or that the strata logged from our borings are necessarily typical across the site. Deviations from our recommendations by plans, written specifications, or field applications shall relieve us of responsibility unless our written concurrence with such deviations has been established. The scope of services for this project does not include either specifically or by implication any environmental or biological assessment of the site or identification or prevention of pollutants, hazardous materials or conditions. If the owner is concerned about the potential for such contamination or pollution, other studies should be undertaken. This report has been prepared for the exclusive use of Solution Blue, Inc. for specific application to the proposed Bongards Facilty Expansion project in Chanhassen, Minnesota. Northern Technologies, LLC has endeavored to comply with generally accepted geotechnical engineering practice common to the local area. Northern Technologies, LLC makes no other warranty, expressed or implied. Northern Technologies, LLC Steven D. Gerber, P.E. Senior Engineer Debra A. Schroeder, P.E. Senior Engineer SDG/das I hereby certify that this plan, specification, or report was prepared by me or under my direct supervision and that I am a Duly Licensed Professional Engineer under the Laws of the State of Minnesota. Steven D. Gerber Date: 10/13/2016 Reg. No. 45298 Bongards Facilty Expansion Chanhassen, Minnesota NTI Project No. 16.61712.100 APPENDIX A GEOTECHNICAL EVALUATION OF RECOVERED SOIL SAMPLES FIELD EXPLORATION PROCEDURES GENERAL NOTES WATER LEVEL SYMBOL DESCRIPTIVE TERMINOLOGY RELATIVE PROPORTIONS PARTICLE SIZES CLASSIFICATION of SOILS for ENGINEERING PURPOSES EXCAVATION OVERSIZE Bongards Facilty Expansion Chanhassen, Minnesota NTI Project No. 16.61712.100 GEOTECHNICAL EVALUATION OF RECOVERED SOIL SAMPLES We visually examined recovered soil samples to estimate distribution of grain sizes, plasticity, consistency, moisture condition, color, presence of lenses and seams, and apparent geologic origin. We then classified the soils according using the Unified Soil Classification System (ASTM D2488). A chart describing this classification system and general notes explaining soil sampling procedures are presented within appendices attachments. The stratification depth lines between soil types on the logs are estimated based on the available data. Insitu, the transition between type(s) may be distinct or gradual in either the horizontal or vertical directions. The soil conditions have been established at our specific boring locations only. Variations in the soil stratigraphy may occur between and around the borings, with the nature and extent of such change not readily evident until exposed by excavation. These variations must be properly assessed when utilizing information presented on the boring logs. We request that you, your design team or contractors contact NTI immediately if local conditions differ from those assumed by this report, as we would need to review how such changes impact our recommendations. Such contact would also allow us to revise our recommendations as necessary to account for the changed site conditions. FIELD EXPLORATION PROCEDURES Soil Sampling – Standard Penetration Boring: Soil sampling was performed according to the procedures described by ASTM D-1586. Using this procedure, a 2 inch O.D. split barrel sampler is driven into the soil by a 140 pound weight falling 30 inches. After an initial set of six inches, the number of blows required to drive the sampler an additional 12 inches is recorded (known as the penetration resistance (i.e. “N-value”) of the soil at the point of sampling. The N-value is an index of the relative density of cohesionless soils and an approximation of the consistency of cohesive soils. Soil Sampling – Power Auger Boring: The boring(s) was/were advanced with a 6 inch nominal diameter continuous flight auger. As a result, samples recovered from the boring are disturbed, and our determination of the depth, extend of various stratum and layers, and relative density or consistency of the soils is approximate. Soil Classification: Soil samples were visually and manually classified in general conformance with ASTM D-2488 as they were removed from the sampler(s). Representative fractions of soil samples were then sealed within respective containers and returned to the laboratory for further examination and verification of the field classification. In addition, select samples were submitted for laboratory tests. Individual sample information, identification of sampling methods, method of advancement of the samples and other pertinent information concerning the soil samples are presented on boring logs and related report attachments. Bongards Facilty Expansion Chanhassen, Minnesota NTI Project No. 16.61712.100 GENERAL NOTES DRILLING and SAMPLING SYMBOLS LABORATORY TEST SYMBOLS SYMBOL DEFINITION SYMBOL DEFINITION C.S. Continuous Sampling W Moisture content-percent of dry weight P.D. 2-3/8” Pipe Drill D Dry Density-pounds per cubic foot C.O. Cleanout Tube LL, PL Liquid and plastic limits determined in accordance with ASTM D 423 and D 424 3 HSA 3 ¼” I.D. Hollow Stem Auger QU Unconfined compressive strength-pounds per square foot in accordance with ASTM D 2166-66 4 FA 4” Diameter Flight Auger 6 FA 6” Diameter Flight Auger 2 ½ C 2 ½” Casing 4 C 4” Casing D.M. Drilling Mud Pq Penetrometer reading-tons/square foot J.W. Jet Water S Torvane reading-tons/square foot H.A. Hand Auger G Specific Gravity – ASTM D 854-58 NXC Size NX Casing SL Shrinkage limit – ASTM 427-61 BXC Size BX Casing Ph Hydrogen ion content-meter method AXC Size AX casing O Organic content-combustion method SS 2” O.D. Split Spoon Sample M.A. Grain size analysis 2T 2” Thin Wall Tube Sample C* One dimensional consolidation 3T 3” Thin Wall Tube Sample QC Triaxial Compression * See attached data Sheet and/or graph WATER LEVEL SYMBOL Water levels shown on the boring logs were determined at the time and under the conditions indicated. In sand, the indicated levels can be considered relatively reliable for most site conditions. In clay soils, it is not possible to determine the ground water level within the normal scope of a test boring investigation, except where lenses or layers of more pervious water bearing soil are present; and then a long period of time may be necessary to reach equilibrium. Therefore, the position of the water level symbol for cohesive or mixed soils may not indicate the true level of the ground water table. The available water level information is given at the bottom of the log sheet. DESCRIPTIVE TERMINOLOGY RELATIVE DENSITY CONSISTENCY TERM N60 Value (corrected) TERM N60 Value (corrected) Very Loose 0 – 4 Soft 0-4 Loose 5 – 8 Medium 5-8 Medium Dense 9 – 16 Rather Stiff 9 – 15 Dense 16 – 30 Stiff 16 – 30 Very Dense Over 30 Very Stiff Over 30 RELATIVE PROPORTIONS PARTICLE SIZES TERMS RANGE MATERIAL DESCRIPTION U.S. SIEVE SIZE Trace 0 – 5% Boulders Over 3” A little 5 – 15% Gravel Coarse 3” to ¾” Some 15 – 30% Medium ¾” to #4 Sand Coarse #4 to #10 Medium #10 to #40 Fine #40 to #200 Silt and Clay Determined by Hydrometer Test Bongards Facilty Expansion Chanhassen, Minnesota NTI Project No. 16.61712.100 CLASSIFICATION of SOILS for ENGINEERING PURPOSES ASTM Designation D-2487 and D2488 (Unified Soil Classification System) Major Divisions Group Symbol Typical Name Classification Criteria Course Grained Soils More than 50% retained on No. 200 sieve * Gravels 50% or more of coarse fraction retained on No. 4 sieve. Clean Gravels GW Well –graded gravels and gravel-sand mixtures, little or no fines. Classification on basis of percentage of fines. Less than 5% passing No. 200 Sieve: GW, GP, SW, SP More than 12% passing No. 200 Sieve: GM, GC, SM, SC From 5% to 12% passing No. 200 Sieve: Borderline Classification requiring use of duel symbols. Cu = D60 / D10 greater than 4. Cz = (D30)2 / (D10 x D60) between 1 & 3. GP Poorly graded gravels and gravel-sand mixtures, little or no fines. Not meeting both criteria for GW materials. Gravels with Fines GM Silty gravels, gravel-sand- silt mixtures. Atterberg limits below “A” line, or P.I. less than 4. Atterberg limits plotting in hatched area are borderline classifications requiring use of dual symbols. GC Clayey gravels, gravel-sand- clay mixtures. Atterberg limits above “A” line with P.I. greater than 7. Sands More than 50% of coarse fraction passes No 4 sieve. Clean Sands SW Well-graded sands and gravelly sands, little or no fines. Cu = D60 / D10 greater than 6. Cz = (D30)2 / (D10 x D60) between 1 & 3. SP Poorly-graded sands and gravelly sands, little or no fines. Not meeting both criteria for SW materials. Sands with Fines SM Silty sands, sand-silt mixtures. Atterberg limits below “A” line, or P.I. less than 4. Atterberg limits plotting in hatched area are borderline classifications requiring use of dual symbols. SC Clayey sands, sand-clay mixtures. Atterberg limits above “A” line with P.I. > 7. Fine Grained Soils More than 50% passes No. 200 sieve * Silts and Clays Liquid Limit of 50% or less ML Inorganic silts, very fine sands, rock flour, silty or clayey fine sands. CL Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, silty clays, lean clays. OL Organic silts and organic silty clays of low plasticity. Silts and Clays Liquid Limit greater than 50%. MH Inorganic silts, micaceous or diatomaceous fine sands or silts, elastic silts. CH Inorganic clays of high plasticity, fat clays. OH Organic clays of medium to high plasticity. Highly Organic Soils Pt Peat, muck and other highly organic soils. Plasticity Index Chart01020304050600102030405060708090100Liquid LimitPlasticity LimitChart for classification of fine grained soils and the fin fraction of coarse grained soils.Atterberg Limits plotting in hatched area are borderline classifications requiring use of dual symbols.OH & MH SoilsCH SoilsCL SoilsOL & ML Soils"A" LineCL-ML Soils Bongards Facilty Expansion Chanhassen, Minnesota NTI Project No. 16.61712.100 EXCAVATION OVERSIZE Excavation oversize facilitates distribution of load induced stress within supporting soils. Unless otherwise superseded by report specific requirements, all construction should conform to the minimum oversize and horizontal offset requirements as presented within the diagram and associated chart. Definitions Oversize Ratio H: The ratio of the horizontal distance divided by the engineered fill depth (i.e. # Horizontal / Depth D). Refer to Chart for specific requirements. Horizontal Offset A: The horizontal distance between the outside edge of footing or critical position and the crest of the engineered fill section. Refer to Chart for specific requirements. Note 1: Excavation depth and sidewall inclination should not exceed those specified in local, state or federal regulations including those defined by Subpart P of Chapter 27, 29 CFR Part 1926 (of Federal Register). Excavations may need to be widened and sloped, or temporarily braced, to maintain or develop a safe work environment. Contractor is solely responsible for assessing stability under “means and methods”. Condition Unsuitable Soil Type Horizontal Offset A Oversize Ratio H Foundation Unit Load equal to or less than 3,000 psf. SP, SM soils, CL & CH soils with cohesion greater than 1,000 psf NA Equal to or greater than one (1) times Depth D Foundation Unit Load greater than 3,000 psf SP, SM soils, CL & CH soils with cohesion less than 1,000 psf NA Equal to or greater than one (1) times Depth D Foundation Unit Load equal to or less than 3,000 psf. Topsoil or Peat 2 feet or width of footing, whichever is greater Equal to or greater than two (2) times Depth D Foundation Unit Load greater than 3,000 psf Topsoil or Peat 5 feet or width of footing, whichever is greater Equal to or greater than two (3) times Depth D Unsuitable Soils (i.e. Excavated Materials), Refer to Chart and report for requirements. Competent Soils (i.e. acceptable for support of embankment and structure), Refer to report for specific requirements. Horizontal Offset A (Refer to Chart) Oversize Ratio H (Refer to Chart) Depth D: Engineered Fill, Refer to report for material type and placement criteria. Structure and/or Basement Backfill Surface & Soils, Refer to report for specific material type and placement Excavation Back Slope (Refer to Note1) Figure 1: Excavation Oversize Bongards Facilty Expansion Chanhassen, Minnesota NTI Project No. 16.61712.100 APPENDIX B GROUNDWATER ISSUES PLACEMENT and COMPACTION OF ENGINEERED FILL Bongards Facilty Expansion Chanhassen, Minnesota NTI Project No. 16.61712.100 GROUNDWATER ISSUES The following presents additional comment and soil specific issues related to measurement of groundwater conditions at your project site. Note that our groundwater measurements, or lack thereof, will vary depending on the time allowed for equilibrium to occur in the borings. Extended observation time was not available during the scope of the field exploration program and, therefore, groundwater measurements as noted on the borings logs may or may not accurately reflect actual conditions at your site. Seasonal and yearly fluctuations of the ground water level, if any, occur. Perched groundwater may be present within sand and silt lenses bedded within cohesive soil formations. Groundwater typically exists at depth within cohesive and cohesionless soils. Documentation of the local groundwater surface and any perched groundwater conditions at the project site would require installation of temporary piezometers and extended monitoring due to the relatively low permeability exhibited by the site soils. We have not performed such groundwater evaluation due to the scope of services authorized for this project. We anticipate that a system of sump pits and pumps located outside of the foundation areas would be suitable for control if perched groundwater were to be encountered. NTI cautions that such seepage may be heavy and will vary based on seasonal and annual precipitation, and ground related impacts in the vicinity of the project. Bongards Facilty Expansion Chanhassen, Minnesota NTI Project No. 16.61712.100 PLACEMENT and COMPACTION OF ENGINEERED FILL Unless otherwise superseded within the body of the Geotechnical Exploration Report, the following criteria shall be utilized for placement of engineered fill on project. This includes, but is not limited to earthen fill placement to improve site grades, fill placed below structural footings, fill placed interior of structure, and fill placed as backfill of foundations. Engineered fill placed for construction, if necessary should consist of natural, non-organic, competent soils native to the project area. Such soils may include, but are not limited to gravel, sand, or clays with Unified Soil Classification System (ASTM D2488) classifications of GW, SP, or SM. Use of silt or clayey silt as project fill will require additional review and approval of project Geotechnical Engineer of Record. Such soils have USCS classifications of ML, MH, ML-CL, MH-CH. Use of topsoil, marl, peat, other organic soils construction debris and/or other unsuitable materials as fill is not allowed. Such soils have USCS classifications of OL, OH, Pt. Engineered fill, classified as clay, should be tempered such that the moisture content at the time of placement is equal to and no more than 3 percent above the optimum content for as defined by the appropriate proctor test. Likewise, engineered fill classified as gravel or sand should be tempered such that the moisture content at the time of placement is within 3 percent of the optimum content. All engineered fill for construction should be placed in individual 8 inch maximum depth lifts. Each lift of fill should be compacted by large vibratory equipment until the in-place soil density is equal to or greater than the criteria established within the following tabulation. Type of Construction Compaction Criteria (% respective Proctor) 1 Clay Sand or Gravel General Embankment Fill Min. 95 Min. 95 Engineered Fill below Foundations Min. 98 Min. 98 Engineered Fill below Floor Slabs Min. 95 Min. 95 Engineered Fill placed as Pavement Aggregate Base NA Min. 100 Engineered Fill placed to within 3 feet of pavement aggregate base Min. 95 Min. 95 Engineered Fill placed within 3 feet of pavement aggregate base Min. 100 Min. 100 Note 1 Unless otherwise required, compaction shall be based on the Standard Proctor Test (ASTM D698). Density tests should be taken during engineered fill placement to document earthwork has achieved necessary compaction of the material(s). Recommendations for interior fill placement and backfill of foundation walls are presented within other sections of this report. Bongards Facilty Expansion Chanhassen, Minnesota NTI Project No. 16.61712.100 APPENDIX C BORING LOCATION DIAGRAM SOIL BORING LOGS Boring Location Diagram Bongards Facility Chanhassen, Minnesota NTI Project #: 16.61712.100 NOTE: Boring locations are approximate. Completed Soil Borings: AU 1 SS 2 SS 3 SS 4 SS 5 SS 6 SS 7 SS 8 3-5-4 (9) 4-6-6 (12) 6-5-5 (10) 8-7-7 (14) 8-6-6 (12) 6-8-7 (15) 7-8-7 (15) 938.3 934.0 918.0 22 19 28 67 100 100 100 100 100 100 0.7 5.0 21.0 TOPSOIL (8 Inches) SANDY LEAN CLAY, (CL) dark brown to brown, saturated to moist, trace gravel (Fill) NOTE: Organic content at 2 feet = 3.6%. SANDY LEAN CLAY, (CL) brown, moist, rather stiff, trace gravel, with occasional silt and sand seams (Glacial Till) Bottom of borehole at 21.0 feet. DRILLING METHOD 3 1/4 in H.S.A LOGGED BY Robert Hawkins CHECKED BY Steve Gerber DATE STARTED 10/7/16 COMPLETED 10/7/16 DRILLING CONTRACTOR NTI GROUND WATER LEVELS: AT END OF DRILLING --- AFTER DRILLING ---FROST DEPTH (ft)---CAVE IN (ft)--- NOTES Elevation determined using Trimble GeoXH 6000. (NAD 1983 (Conus) CORS 96 datum) GROUND ELEVATION 939 ft HOLE SIZE 6 1/2 in. AT TIME OF DRILLING 2.00 ft / Elev 937.00 ft Perched ATTERBERG LIMITS PLASTICLIMITGRAPHICLOGDEPTH(ft)0 5 10 15 20 SAMPLE TYPENUMBERBLOWCOUNTS(N VALUE)POCKET PEN.(tsf)MOISTURECONTENT (%)LIQUIDLIMITRECOVERY %(RQD)FINESDRY UNIT WT.(pcf)PLASTICITYINDEXMATERIAL DESCRIPTION PAGE 1 OF 1 BORING NUMBER SB-1 PROJECT LOCATION Chanhassen, MN CLIENT Solution Blue, Inc. PROJECT NUMBER 16.61712.100 PROJECT NAME Bongards Facility NTI GEOTECH COLUMNS W/NOTES - NTI 2016-08-10.GDT - 10/13/16 12:27 - H:\RAMSEY\1-PROJECTS\2016 PROJECTS\BONGARDS FACILITY - GEO - (16.61712.100)\ENGINEERING\ENGINEERING REPORTS\GINT\BONGARDS.GPJInver Grove Heights 6160 Carmen Ave. E Inver Grove Heights, MN, 55076 P: 651-389-4191 www.NTIGeo.com AU 1 SS 2 SS 3 SS 4 SS 5 SS 6 SS 7 SS 8 4-6-5 (11) 4-5-6 (11) 5-7-7 (14) 5-8-7 (15) 5-7-9 (16) 5-6-7 (13) 6-6-6 (12) 941.6 937.5 921.0 20 21 100 100 100 100 100 100 100 52 0.4 4.5 21.0 TOPSOIL (8 Inches) SANDY LEAN CLAY, (CL) dark brown to brown, moist, trace gravel (Fill) SANDY LEAN CLAY, (CL) brown, moist, rather stiff to stiff, trace gravel, occasional silt and sand seams (Glacial Till) NOTE: Grades to light brown at 14.5 feet. Bottom of borehole at 21.0 feet. DRILLING METHOD 3 1/4 in H.S.A LOGGED BY Robert Hawkins CHECKED BY Steve Gerber DATE STARTED 10/7/16 COMPLETED 10/7/16 DRILLING CONTRACTOR NTI GROUND WATER LEVELS: AT END OF DRILLING --- AFTER DRILLING ---FROST DEPTH (ft)---CAVE IN (ft)--- NOTES Elevation determined using Trimble GeoXH 6000. (NAD 1983 (Conus) CORS 96 datum) GROUND ELEVATION 942 ft HOLE SIZE 6 1/2 in. AT TIME OF DRILLING --- No groundwater encountered ATTERBERG LIMITS PLASTICLIMITGRAPHICLOGDEPTH(ft)0 5 10 15 20 SAMPLE TYPENUMBERBLOWCOUNTS(N VALUE)POCKET PEN.(tsf)MOISTURECONTENT (%)LIQUIDLIMITRECOVERY %(RQD)FINESDRY UNIT WT.(pcf)PLASTICITYINDEXMATERIAL DESCRIPTION PAGE 1 OF 1 BORING NUMBER SB-2 PROJECT LOCATION Chanhassen, MN CLIENT Solution Blue, Inc. PROJECT NUMBER 16.61712.100 PROJECT NAME Bongards Facility NTI GEOTECH COLUMNS W/NOTES - NTI 2016-08-10.GDT - 10/13/16 12:27 - H:\RAMSEY\1-PROJECTS\2016 PROJECTS\BONGARDS FACILITY - GEO - (16.61712.100)\ENGINEERING\ENGINEERING REPORTS\GINT\BONGARDS.GPJInver Grove Heights 6160 Carmen Ave. E Inver Grove Heights, MN, 55076 P: 651-389-4191 www.NTIGeo.com AU 1 SS 2 SS 3 SS 4 SS 5 SS 6 SS 7 SS 8 2-4-6 (10) 5-5-7 (12) 7-8-8 (16) 6-7-7 (14) 6-6-5 (11) 7-6-6 (12) 7-12-50/3" 940.6 936.0 920.3 56 100 100 100 100 89 100 0.4 5.0 20.8 TOPSOIL (5 Inches) SANDY LEAN CLAY, (CL) dark brown to brown, moist, trace gravel (Fill) SANDY LEAN CLAY, (CL) brown, moist, rather stiff, trace gravel, occasional silt and sand seams, occasional cobbles (Glacial Till) Bottom of borehole at 20.8 feet. DRILLING METHOD 3 1/4 in H.S.A LOGGED BY Robert Hawkins CHECKED BY Steve Gerber DATE STARTED 10/7/16 COMPLETED 10/7/16 DRILLING CONTRACTOR NTI GROUND WATER LEVELS: AT END OF DRILLING --- AFTER DRILLING ---FROST DEPTH (ft)---CAVE IN (ft)--- NOTES Elevation determined using Trimble GeoXH 6000. (NAD 1983 (Conus) CORS 96 datum) GROUND ELEVATION 941 ft HOLE SIZE 6 1/2 in. AT TIME OF DRILLING 20.50 ft / Elev 920.50 ft ATTERBERG LIMITS PLASTICLIMITGRAPHICLOGDEPTH(ft)0 5 10 15 20 SAMPLE TYPENUMBERBLOWCOUNTS(N VALUE)POCKET PEN.(tsf)MOISTURECONTENT (%)LIQUIDLIMITRECOVERY %(RQD)FINESDRY UNIT WT.(pcf)PLASTICITYINDEXMATERIAL DESCRIPTION PAGE 1 OF 1 BORING NUMBER SB-3 PROJECT LOCATION Chanhassen, MN CLIENT Solution Blue, Inc. PROJECT NUMBER 16.61712.100 PROJECT NAME Bongards Facility NTI GEOTECH COLUMNS W/NOTES - NTI 2016-08-10.GDT - 10/13/16 12:27 - H:\RAMSEY\1-PROJECTS\2016 PROJECTS\BONGARDS FACILITY - GEO - (16.61712.100)\ENGINEERING\ENGINEERING REPORTS\GINT\BONGARDS.GPJInver Grove Heights 6160 Carmen Ave. E Inver Grove Heights, MN, 55076 P: 651-389-4191 www.NTIGeo.com AU 1 SS 2 SS 3 SS 4 SS 5 SS 6 SS 7 SS 8 3-6-6 (12) 5-6-6 (12) 5-9-8 (17) 8-7-7 (14) 6-6-7 (13) 7-6-7 (13) 7-6-6 (12) 940.5 936.0 920.0 89 100 100 100 100 100 100 0.6 5.0 21.0 TOPSOIL (6 1/2 Inches) SANDY LEAN CLAY, (CL) dark brown to brown, moist, trace gravel (Fill) SANDY LEAN CLAY, (CL) brown, moist, rather stiff to stiff, trace gravel, occasional silt and sand seams (Glacial Till) NOTE: Brown to light brown below 12 feet. Bottom of borehole at 21.0 feet. DRILLING METHOD 3 1/4 in H.S.A LOGGED BY Robert Hawkins CHECKED BY Steve Gerber DATE STARTED 10/7/16 COMPLETED 10/7/16 DRILLING CONTRACTOR NTI GROUND WATER LEVELS: AT END OF DRILLING --- AFTER DRILLING ---FROST DEPTH (ft)---CAVE IN (ft)--- NOTES Elevation determined using Trimble GeoXH 6000. (NAD 1983 (Conus) CORS 96 datum) GROUND ELEVATION 941 ft HOLE SIZE 6 1/2 in. AT TIME OF DRILLING --- No groundwater encountered ATTERBERG LIMITS PLASTICLIMITGRAPHICLOGDEPTH(ft)0 5 10 15 20 SAMPLE TYPENUMBERBLOWCOUNTS(N VALUE)POCKET PEN.(tsf)MOISTURECONTENT (%)LIQUIDLIMITRECOVERY %(RQD)FINESDRY UNIT WT.(pcf)PLASTICITYINDEXMATERIAL DESCRIPTION PAGE 1 OF 1 BORING NUMBER SB-4 PROJECT LOCATION Chanhassen, MN CLIENT Solution Blue, Inc. PROJECT NUMBER 16.61712.100 PROJECT NAME Bongards Facility NTI GEOTECH COLUMNS W/NOTES - NTI 2016-08-10.GDT - 10/13/16 12:27 - H:\RAMSEY\1-PROJECTS\2016 PROJECTS\BONGARDS FACILITY - GEO - (16.61712.100)\ENGINEERING\ENGINEERING REPORTS\GINT\BONGARDS.GPJInver Grove Heights 6160 Carmen Ave. E Inver Grove Heights, MN, 55076 P: 651-389-4191 www.NTIGeo.com AU 1 SS 2 SS 3 SS 4 SS 5 SS 6 SS 7 SS 8 0-2-2 (4) 3-4-5 (9) 2-6-6 (12) 4-5-8 (13) 5-7-7 (14) 4-6-7 (13) 5-6-7 (13) 942.2 938.0 930.5 923.0 921.5 23 17 22 44 100 100 100 100 100 100 0.3 4.5 12.0 19.5 21.0 TOPSOIL (4 Inches) SANDY LEAN CLAY, (CL) dark brown to brown, moist, trace gravel (Fill) NOTE: Organic content at 2 feet = 4.0%. SANDY LEAN CLAY, (CL) brown, moist, rather stiff, trace gravel, occasional silt and sand seams (Glacial Till) NOTE: Brown to gray below 9.5 feet. CLAYEY SAND, (SC) brown, fine grained, moist, medium dense, trace gravel (Glacial Till) SANDY LEAN CLAY, (CL) dark gray, moist, rather stiff, trace gravel, occasional silt (ML) seams (Glacial Till) Bottom of borehole at 21.0 feet. DRILLING METHOD 3 1/4 in H.S.A LOGGED BY Robert Hawkins CHECKED BY Steve Gerber DATE STARTED 10/7/16 COMPLETED 10/7/16 DRILLING CONTRACTOR NTI GROUND WATER LEVELS: AT END OF DRILLING --- AFTER DRILLING ---FROST DEPTH (ft)---CAVE IN (ft)--- NOTES Elevation determined using Trimble GeoXH 6000. (NAD 1983 (Conus) CORS 96 datum) GROUND ELEVATION 942.5 ft HOLE SIZE 6 1/2 in. AT TIME OF DRILLING --- No groundwater encountered ATTERBERG LIMITS PLASTICLIMITGRAPHICLOGDEPTH(ft)0 5 10 15 20 SAMPLE TYPENUMBERBLOWCOUNTS(N VALUE)POCKET PEN.(tsf)MOISTURECONTENT (%)LIQUIDLIMITRECOVERY %(RQD)FINESDRY UNIT WT.(pcf)PLASTICITYINDEXMATERIAL DESCRIPTION PAGE 1 OF 1 BORING NUMBER SB-5 PROJECT LOCATION Chanhassen, MN CLIENT Solution Blue, Inc. PROJECT NUMBER 16.61712.100 PROJECT NAME Bongards Facility NTI GEOTECH COLUMNS W/NOTES - NTI 2016-08-10.GDT - 10/13/16 12:27 - H:\RAMSEY\1-PROJECTS\2016 PROJECTS\BONGARDS FACILITY - GEO - (16.61712.100)\ENGINEERING\ENGINEERING REPORTS\GINT\BONGARDS.GPJInver Grove Heights 6160 Carmen Ave. E Inver Grove Heights, MN, 55076 P: 651-389-4191 www.NTIGeo.com AU 1 SS 2 SS 3 SS 4 SS 5 SS 6 SS 7 SS 8 3-4-5 (9) 6-6-7 (13) 4-8-6 (14) 7-8-7 (15) 8-6-7 (13) 6-7-7 (14) 6-8-6 (14) 942.3 938.0 930.5 921.5 20 14 44 56 89 89 100 100 100 0.3 4.5 12.0 21.0 TOPSOIL (4 Inches) SANDY LEAN CLAY, (CL) brown, moist, trace gravel (Fill) SANDY LEAN CLAY, (CL) brown, moist, rather stiff, trace gravel, occasional silt and sand seams (Glacial Till) CLAYEY SAND, (SC) brown, fine to medium grained, moist to saturated, medium dense, trace gravel (Glacial Till) NOTE: Grades to gray to brown below 14.5 feet. Bottom of borehole at 21.0 feet. DRILLING METHOD 3 1/4 in H.S.A LOGGED BY Robert Hawkins CHECKED BY Steve Gerber DATE STARTED 10/7/16 COMPLETED 10/7/16 DRILLING CONTRACTOR NTI GROUND WATER LEVELS: AT END OF DRILLING --- AFTER DRILLING ---FROST DEPTH (ft)---CAVE IN (ft)--- NOTES Elevation determined using Trimble GeoXH 6000. (NAD 1983 (Conus) CORS 96 datum) GROUND ELEVATION 942.5 ft HOLE SIZE 6 1/2 in. AT TIME OF DRILLING 18.00 ft / Elev 924.50 ft ATTERBERG LIMITS PLASTICLIMITGRAPHICLOGDEPTH(ft)0 5 10 15 20 SAMPLE TYPENUMBERBLOWCOUNTS(N VALUE)POCKET PEN.(tsf)MOISTURECONTENT (%)LIQUIDLIMITRECOVERY %(RQD)FINESDRY UNIT WT.(pcf)PLASTICITYINDEXMATERIAL DESCRIPTION PAGE 1 OF 1 BORING NUMBER SB-6 PROJECT LOCATION Chanhassen, MN CLIENT Solution Blue, Inc. PROJECT NUMBER 16.61712.100 PROJECT NAME Bongards Facility NTI GEOTECH COLUMNS W/NOTES - NTI 2016-08-10.GDT - 10/13/16 12:27 - H:\RAMSEY\1-PROJECTS\2016 PROJECTS\BONGARDS FACILITY - GEO - (16.61712.100)\ENGINEERING\ENGINEERING REPORTS\GINT\BONGARDS.GPJInver Grove Heights 6160 Carmen Ave. E Inver Grove Heights, MN, 55076 P: 651-389-4191 www.NTIGeo.com AU 1 SS 2 SH 3 SS 4 SS 5 SS 6 SS 7 SS 8 3-4-6 (10) 5-7-7 (14) 3-7-9 (16) 3-5-7 (12) 3-4-6 (10) 4-7-7 (14) 940.2 937.0 932.0 920.5 17 24 83 89 94 83 78 94 1.3 4.5 9.5 21.0 TOPSOIL (16 Inches) SANDY LEAN CLAY, (CL) brown, moist, trace gravel (Fill) SANDY LEAN CLAY, (CL) brown to gray, moist, rather stiff, trace gravel (Glacial Till) NOTE: Brown below 7 feet. CLAYEY SAND, (SC) brown, fine to medium grained, moist to saturated, medium dense, trace gravel (Glacial Till) NOTE: Sand layer at 9.5 feet. Bottom of borehole at 21.0 feet. DRILLING METHOD 3 1/4 in H.S.A LOGGED BY Robert Hawkins CHECKED BY Steve Gerber DATE STARTED 10/5/16 COMPLETED 10/5/16 DRILLING CONTRACTOR NTI GROUND WATER LEVELS: AT END OF DRILLING --- AFTER DRILLING ---FROST DEPTH (ft)---CAVE IN (ft)--- NOTES Elevation determined using Trimble GeoXH 6000. (NAD 1983 (Conus) CORS 96 datum) GROUND ELEVATION 941.5 ft HOLE SIZE 6 1/2 in. AT TIME OF DRILLING 12.00 ft / Elev 929.50 ft ATTERBERG LIMITS PLASTICLIMITGRAPHICLOGDEPTH(ft)0 5 10 15 20 SAMPLE TYPENUMBERBLOWCOUNTS(N VALUE)POCKET PEN.(tsf)MOISTURECONTENT (%)LIQUIDLIMITRECOVERY %(RQD)FINESDRY UNIT WT.(pcf)PLASTICITYINDEXMATERIAL DESCRIPTION PAGE 1 OF 1 BORING NUMBER SB-7 PROJECT LOCATION Chanhassen, MN CLIENT Solution Blue, Inc. PROJECT NUMBER 16.61712.100 PROJECT NAME Bongards Facility NTI GEOTECH COLUMNS W/NOTES - NTI 2016-08-10.GDT - 10/13/16 12:27 - H:\RAMSEY\1-PROJECTS\2016 PROJECTS\BONGARDS FACILITY - GEO - (16.61712.100)\ENGINEERING\ENGINEERING REPORTS\GINT\BONGARDS.GPJInver Grove Heights 6160 Carmen Ave. E Inver Grove Heights, MN, 55076 P: 651-389-4191 www.NTIGeo.com AU 1 SS 2 SS 3 SS 4 SS 5 SS 6 SS 7 SS 8 SS 9 3-4-5 (9) 3-4-4 (8) 3-3-3 (6) 3-3-3 (6) 7-9-10 (19) 7-10-10 (20) 7-6-6 (12) 3-7-10 (17) 941.2 937.0 929.5 920.5 17 21 83 89 78 89 0 56 61 89 48 0.3 4.5 12.0 21.0 TOPSOIL (4 Inches) SANDY LEAN CLAY, (CL) brown, moist, trace gravel (Fill) CLAYEY SAND, (SC) brown, moist, medium, trace gravel (Glacial Till) SANDY LEAN CLAY, (CL) brown, fine to coarse grained, saturated, stiff to rather stiff, trace gravel (Glacial Till) NOTE: Sand seam at 15 feet. Bottom of borehole at 21.0 feet. DRILLING METHOD 3 1/4 in H.S.A LOGGED BY Robert Hawkins CHECKED BY Steve Gerber DATE STARTED 10/5/16 COMPLETED 10/5/16 DRILLING CONTRACTOR NTI GROUND WATER LEVELS: AT END OF DRILLING --- AFTER DRILLING ---FROST DEPTH (ft)---CAVE IN (ft)--- NOTES Elevation determined using Trimble GeoXH 6000. (NAD 1983 (Conus) CORS 96 datum) GROUND ELEVATION 941.5 ft HOLE SIZE 6 1/2 in. AT TIME OF DRILLING 12.00 ft / Elev 929.50 ft ATTERBERG LIMITS PLASTICLIMITGRAPHICLOGDEPTH(ft)0 5 10 15 20 SAMPLE TYPENUMBERBLOWCOUNTS(N VALUE)POCKET PEN.(tsf)MOISTURECONTENT (%)LIQUIDLIMITRECOVERY %(RQD)FINESDRY UNIT WT.(pcf)PLASTICITYINDEXMATERIAL DESCRIPTION PAGE 1 OF 1 BORING NUMBER SB-8 PROJECT LOCATION Chanhassen, MN CLIENT Solution Blue, Inc. PROJECT NUMBER 16.61712.100 PROJECT NAME Bongards Facility NTI GEOTECH COLUMNS W/NOTES - NTI 2016-08-10.GDT - 10/13/16 12:27 - H:\RAMSEY\1-PROJECTS\2016 PROJECTS\BONGARDS FACILITY - GEO - (16.61712.100)\ENGINEERING\ENGINEERING REPORTS\GINT\BONGARDS.GPJInver Grove Heights 6160 Carmen Ave. E Inver Grove Heights, MN, 55076 P: 651-389-4191 www.NTIGeo.com 06 /30/2017 BONGARDS EXPANSION: STORMWATER MANAGEMEN T PLAN D APPENDIX D: P8 MODEL RESULTS Bongards Loading - Additional Impervious Total Inflow (lbs/yr) Variable OVERALL P0%2.365 P10%52.347 P30%52.347 P50%52.347 P80%104.694 TSS 261.735 TP 0.839 TKN 3.775 CU 0.121 PB 0.052 ZN 0.403 HC 6.48 Bongards Removals - Treatment by Underground Infiltration Total Trapped (lbs/yr) Variable OVERALL UNDERGROUND INFILTRATION P0%2.173 2.173 P10%58.869 58.869 P30%61.706 61.706 P50%62.314 62.314 P80%124.845 124.845 TSS 307.734 307.734 TP 0.919 0.919 TKN 4.047 4.047 CU 0.134 0.134 PB 0.06 0.06 ZN 0.432 0.432 HC 7.467 7.467