Loading...
The URL can be used to link to this page
Your browser does not support the video tag.
Home
My WebLink
About
2024-04-08 Stormwater Management Report by CivilSite Group
„ Stormwater Management Report Owner: Hampton Companies RECEIVED MAY 13 2024 1824 Buerkle Road White Bear Lake, MN 55110 Project: Oak Park Heights Apartments 58th St. N Oak Park Heights, MN 55082 Engineer's Certification: All plans and supporting Documentation contained in this report have been reviewed by me and it is hereby certified that to the best of my knowledge the plans comply with the requirements of the ordinance. I hereby certify that this report was prepared by me or under my direct supervision and that I am a duly Registered Professional Engineer under the laws of the State of Minnesota. Robert A. Latta P.E. Registration Number: 59612 Date: 04/08/2024 www.CivilSiteGroup.com 5000 Glenwood Ave•Golden Valley•Minnesota •55422 (612)615-0060 çiyijsite UP Table of Contents: 1.0 Cover Sheet, Engineer's Certification 2.0 Summary Analysis/Narrative 2.1 Introduction 2.2 Existing Site Conditions 2.3 Proposed Site Conditions 2.4 Stormwater Requirements—City 2.5 Stormwater Requirements—Watershed District 2.6 Stormwater Requirements—MPCA/NPDES 3.0 Stormwater Calculations 3.1 Proposed Stormwater Management Strategy& Facilities Description 3.2 Rate Control 3.3 Water Quality 3.4 Volume Control 4.0 Conclusions Figures: Figure 1 —Existing Conditions Drainage Area map Figure 2—Proposed Conditions Drainage Area Map Appendices: • HydroCAD Existing Conditions HydroCAD Modeling Proposed Conditions HydroCAD Modeling • Drainage Calculations Summary Table • Geotechnical Report Civil Site Group, PC •4931 West 35th Street• Suite 200•St. Louis Park•Minnesota •55416 www.CivilSiteGroup.com •(612)615-0060 C 71) Site 2.0 Summary Analysis / Narrative: 2.1 Introduction: This stormwater management report accompanies the Civil Engineering Plans prepared by Civil Site Group for the subject project dated 04/08/2024. This report includes a summary of the existing and proposed site conditions, the stormwater requirements of relevant regulatory agencies, and proposed design calculations and data to meet the requirements. 2.2 Existing Site Conditions : Site Description: The existing site is a tree farm with no impervious surfaces. Drainage Area Imperious Area Pervious Area Total Area Area[SF] CN Value Area[SF] CN Value Area[SF] CN Value EX1 0 98 264143 61 264143 61 Existing Soils: Geotechnical borings were completed on 9/7/2021 with a full geotechnical report completed 10/11/2021. Boring logs show poorly graded sand, poorly graded sand with silt, silty sand, and lean clay, among other soil types. Groundwater: Groundwater was not encountered in any of the borings taken. 2.3 Proposed Site Conditions: Site Description: The proposed site is a multi-family residential building with associated parking, landscaping, utility and stormwater improvements. This site is within the city of Oak Park Heights Drinking Water Supply Management Area (DWSMA), so stormwater infiltration practices are prohibited. The proposed site surface coverage areas are shown in the table below: Drainage Area Impervious Area Pervious Area Total Area Area[SF] CN Value Area[SF] CN Value Area[SF] CN Value PR1 424 98 113284 61 113708 61 PR2 49764 98 49896 61 99660 79 PR3 34089 98 16686 61 50775 86 2.4 Stormwater Requirements City (Oak Park Heights): The city defers to Brown's Creek Watershed District 2.5 Stormwater Requirements Watershed District—(Brown's Creek Watershed District)): Rate control—n/a. Site drains to"Menard's Pond"which provides regional rate control. Water quality—Removal of 75% of the annual total phosphorus loading. Volume control—Retention onsite of 1.1 inches of stormwater from the regulated impervious surface. 2.6 Stormwater Requirements -Minnesota Pollution Control Agency—NPPDES permit(MPCA): Civil Site Group, PC •4931 West 35th Street•Suite 200•St. Louis Park•Minnesota •55416 www.CivilSiteGroup.com •(612)615-0060 c±yJsite O up Requirement threshold -A permit is required for projects with a disturbed area over 1 acre in size, Stormwater management is required for a project adding 1-acre of more of NEW impervious surface (reconstructed impervious is not included). Rate Control-No specific regulation, may not degrade downstream facilities. Water Quality-Stormwater water quality treatment volume must be provided equal to 1.0" over all new impervious surfaces (includes all newly constructed impervious surfaces only, re-constructed impervious surfaces are not included). Volume Control-Must consider volume reduction if feasible and not prohibited on site. The required infiltration volume is equal to the water quality volume described above. 3.0 Stormwater Calculations: 3.1 Proposed Stormwater Management Strategy & Facilities Description The project proposes to add 2.1 acres of impervious surface. Two BMPs will be constructed to achieve the water quality requirements, an aboveground filtration basin, and an underground filtration basin with sand filter. Rate control is not required per discussions with EOR staff under contract with Brown's Creek Watershed District. 3.2 Rate Control Rate control is not proposed for this site. The site and BMP discharge rates for the 2-yr, 10-year, and 100-yr storm are below. Drainage Area Existing Rate (cfs) 2-YR [2.94"] 10-YR[4.47"] 100-YR [7.81"] EX1 2.61 11.31 37.37 TOTAL 2.61 11.31 37.37 Drainage Area Proposed Conditions Rate (cfs) 2-YR[2.94"] 10-YR [4.471 100-YR[7.81"] PR1 1.16 4.92 16.14 PR2 (2P) 4.88 9.05 19.49 PR3 (3P) 0.10 0.66 7.89 TOTAL 6.13 13.99 42.30 3.3 Water Quality An aboveground filtration basin, and an underground filtration basin are proposed to achieve the water quality requirement of 75%total phosphorus annual removal. 3.4 Volume Control The filtration basins are proposed to provide 1.48"filtration for the site. 10,406 cf is provided where 7,725 cf is required to meet the 1.1"volume requirement. See the volume summary below. Proposed BMP Area Provided Vol (cf) Drawdown Time Calculations (0.8"/Hour) Inf. Area(sf) Assoc. Inf. Height(ft) Drawdown Time(h) Aboveground Filtration Basin 3897 1955 1.99 14.95 Underground Filtration Basin 6509 2796 2.33 17.46 TOTAL 10406 Civil Site Group,PC •4931 West 35th Street•Suite 200•St. Louis Park •Minnesota •55416 www.CivilSiteGroup.com •(612)615-0060 4.0 Conclusions: To the best of our knowledge, this project meets all State, City and Watershed District stormwater management requirements. Civil Site Group, PC •4931 West 35th Street•Suite 200•St. Louis Park•Minnesota •55416 www.CivilSiteGroup.com •(612)615-0060 on s*is / //IV/ t} t../ o'' / 'f V� r I ti I /7/ t � { 17 e,D ` t 1 / j7�j/;;/ \ `vi 0 1E.t 70 „ )3j. �) 1 ii :// ,:1/4/11/9///// jt t, m t '/ t, 1 714 i /7 - -- 11/111i I co 33 1 m \,i :(71,, z f�1 1' M x93 11 s�* ! II 1 IJ •o� I II� ,i 1 1 IE k Ir le 11 I' D 1 f�� ` x I i 3" I g r x I J ! m i If/A 1 i D 1*1' ` m ri I II — — rr, I !F DmEo an--"- � m�OAvv _ 1t i Ir- OIC I • .' /7 r. I J ti ri[ i � aN N>'O TmO f 1 t V O _;_4iik_1 _/ iii t- N — rri C u u u u Di � ....._.. f � 1 r, , _ , 1 \ 1 i 6 Z ----- l' F. p , Fs I . t 'II3 // 1 r ' 1 • 1 b 1 > I N g 1 6 KEXI .. EX1 _ DRAINS TO EXISTING POND , , <Subca� Reach ALink Routing Diagram for 21361 EXISTING j Prepared by Civil Site Group, Printed 4/5/2024 HydroCAD®10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC 21361 EXISTING Prepared by Civil Site Group Printed 4/5/2024 HydroCAD® 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 2 Project Notes Rainfall events imported from "NRCS-Rain.txt" for 5382 MN Washington Rainfall events imported from "21361 PROPOSED.hcp" Rainfall events imported from "21361 PROPOSED.hcp" 21361 EXISTING Prepared by Civil Site Group Printed 4/5/2024 HydroCAD© 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 3 Rainfall Events Listing Event# Event Storm Type Curve Mode Duration B/B Depth AMC Name (hours) (inches) 1 2y 24hr AT-14 MSE 24-hr 3 Default 24.00 1 2.94 2 2 10y 24hr AT-14 MSE 24-hr 3 Default 24.00 1 4.47 2 3 100y 24hr AT-14 MSE 24-hr 3 Default 24.00 1 7.81 2 21361 EXISTING Prepared by Civil Site Group Printed 4/5/2024 HydroCAD® 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 4 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 6.064 61 >75% Grass cover, Good, HSG B (EX1) 6.064 61 TOTAL AREA 21361 EXISTING Prepared by Civil Site Group Printed 4/5/2024 HydroCAD© 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 5 Soil Listing (all nodes) Area Soil Subcatchment (acres) Group Numbers 0.000 HSG A 6.064 HSG B EX1 0.000 HSG C 0.000 HSG D 0.000 Other 6.064 TOTAL AREA 21361 EXISTING Prepared by Civil Site Group Printed 4/5/2024 HydroCAD© 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 6 Ground Covers (all nodes) HSG-A HSG-B HSG-C HSG-D Other Total Ground Subcatchment (acres) (acres) (acres) (acres) (acres) (acres) Cover Numbers 0.000 6.064 0.000 0.000 0.000 6.064 >75% Grass cover, Good EX1 0.000 6.064 0.000 0.000 0.000 6.064 TOTAL AREA 21361 EXISTING MSE 24-hr 3 2y 24hrAT-14 Rainfall=2.94" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD®10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 7 Time span=0.00-240.00 hrs, dt=0.01 hrs, 24001 points Runoff by SCS TR-20 method, UH=SCS, Weighted-Q Reach routing by Stor-Ind method - Pond routing by Stor-Ind method SubcatchmentEX1: EX1 -DRAINS TO Runoff Area=264,143 sf 0.00% Impervious Runoff Depth=0.34" Tc=6.0 min CN=61 Runoff=2.61 cfs 0.173 af Total Runoff Area = 6.064 ac Runoff Volume = 0.173 af Average Runoff Depth = 0.34" 100.00% Pervious = 6.064 ac 0.00% Impervious = 0.000 ac 21361 EXISTING MSE 24-hr 3 2y 24hr AT-14 Rainfall=2.94" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD® 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 8 Summary for Subcatchment EX1: EX1 - DRAINS TO EXISTING POND Runoff = 2.61 cfs @ 12.15 hrs, Volume= 0.173 af, Depth= 0.34" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-240.00 hrs, dt= 0.01 hrs MSE 24-hr 3 2y 24hr AT-14 Rainfall=2.94" Area (sf) CN Description 264,143 61 >75% Grass cover, Good, HSG B 264,143 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment EX1: EX1 - DRAINS TO EXISTING POND Hydrograph El Runoff` I 2.61 efs MSE 24-hr 3 2y 24hr AT-14 Rainfall=2.94" Runoff Area=264,143 sf 2- Runoff Volume=0.173 of _ , Runoff Depth=0.34" - Tc=6.0 min T. CN=61 1- 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 Time (hours) 21361 EXISTING MSE 24-hr 3 10y 24hrAT-14 Rainfall=4.47" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD© 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 9 Time span=0.00-240.00 hrs, dt=0.01 hrs, 24001 points Runoff by SCS TR-20 method, UH=SCS, Weighted-Q Reach routing by Stor-Ind method - Pond routing by Stor-Ind method SubcatchmentEX1: EX1 -DRAINS TO Runoff Area=264,143 sf 0.00% Impervious Runoff Depth=1.06" Tc=6.0 min CN=61 Runoff=11.31 cfs 0.537 af Total Runoff Area = 6.064 ac Runoff Volume = 0.537 af Average Runoff Depth = 1.06" 100.00% Pervious = 6.064 ac 0.00% Impervious = 0.000 ac 21361 EXISTING MSE 24-hr 3 10y 24hr AT-14 Rainfall=4.47" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD© 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 10 Summary for Subcatchment EX1: EX1 - DRAINS TO EXISTING POND Runoff = 11.31 cfs @ 12.14 hrs, Volume= 0.537 af, Depth= 1.06" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-240.00 hrs, dt= 0.01 hrs MSE 24-hr 3 10y 24hr AT-14 Rainfall=4.47" Area (sf) CN Description 264,143 61 >75% Grass cover, Good, HSG B 264,143 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment EX1: EX1 - DRAINS TO EXISTING POND Hydrograph D Runoff 12- 11131 cfs 1 MSE 24-hr 3 10. / 10y 24hr AT-14 Rainfall=4.47" / Runoff Area=264,143 sf 9— / Runoff Volume=0.537 of 8 / Runoff Depth=1.06" '- / Tc=6.0 min 6] CN=61 5- 4— 2 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 Time (hours) 21361 EXISTING MSE 24-hr 3 100y 24hr AT-14 Rainfall=7.81" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD® 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 11 Time span=0.00-240.00 hrs, dt=0.01 hrs, 24001 points Runoff by SCS TR-20 method, UH=SCS, Weighted-Q Reach routing by Stor-Ind method - Pond routing by Stor-Ind method SubcatchmentEX1: EX1 -DRAINS TO Runoff Area=264,143 sf 0.00% Impervious Runoff Depth=3.30" Tc=6.0 min CN=61 Runoff=37.37 cfs 1.668 af Total Runoff Area = 6.064 ac Runoff Volume = 1.668 af Average Runoff Depth = 3.30" 100.00% Pervious = 6.064 ac 0.00% Impervious = 0.000 ac 21361 EXISTING MSE 24-hr 3 100y 24hr AT-14 Rainfall=7.81" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD®10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 12 Summary for Subcatchment EX1: EX1 - DRAINS TO EXISTING POND Runoff = 37.37 cfs @ 12.14 hrs, Volume= 1.668 af, Depth= 3.30" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-240.00 hrs, dt= 0.01 hrs MSE 24-hr 3 100y 24hr AT-14 Rainfall=7.81" Area (sf) CN Description 264,143 61 >75% Grass cover, Good, HSG B 264,143 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment EX1: EX1 - DRAINS TO EXISTING POND Hydrograph 40. 0 Runoff` 38 137.37 cfs MSE 24-hr 3 36_ 34= / 100y 24hr AT-14 Rainfall=7.81" 321Runoff Area=264,143 sf 30_ / 281 Runoff Volume=1.668 af 26 Runoff Depth=3.30" 24_ / 11 22= / Tc=6.0 min 0 20= CN=61 u- 18. 16, 14; 10: 6 ef 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 Time (hours) PR2 PR2 (DRAI S TO 2P) <PR3> (PR1 PR3 (DRAINS TO 3P) PR1 (TO EXIS NG POND) 2P 3P P -ABOVEGROUND FILTRATION BASIN UNDE ROUND FILTRA ION BASIN 4 , 2R EXISTING POND • Subcat Reach -on• MI Routing Diagram for 21361 PROPOSED Prepared by Civil Site Group, Printed 4/5/2024 HydroCAD®10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC 21361 PROPOSED Prepared by Civil Site Group Printed 4/5/2024 HydroCAD© 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 2 Rainfall Events Listing Event# Event Storm Type Curve Mode Duration B/B Depth AMC Name (hours) (inches) 1 2y 24hr AT-14 MSE 24-hr 3 Default 24.00 1 2.94 2 2 10y 24hr AT-14 MSE 24-hr 3 Default 24.00 1 4.47 2 3 100y 24hr AT-14 MSE 24-hr 3 Default 24.00 1 7.81 2 21361 PROPOSED Prepared by Civil Site Group Printed 4/5/2024 HydroCAD® 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 3 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 4.129 61 >75% Grass cover, Good, HSG B (PR1, PR2, PR3) 1.935 98 Paved parking, HSG B (PR1, PR2, PR3) 6.064 73 TOTAL AREA 21361 PROPOSED Prepared by Civil Site Group Printed 4/5/2024 HydroCAD© 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 4 Soil Listing (all nodes) Area Soil Subcatchment (acres) Group Numbers 0.000 HSG A 6.064 HSG B PR1, PR2, PR3 0.000 HSG C 0.000 HSG D 0.000 Other 6.064 TOTAL AREA 21361 PROPOSED Prepared by Civil Site Group Printed 4/5/2024 HydroCAD© 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 5 Ground Covers (all nodes) HSG-A HSG-B HSG-C HSG-D Other Total Ground Subcatchment (acres) (acres) (acres) (acres) (acres) (acres) Cover Numbers 0.000 4.129 0.000 0.000 0.000 4.129 >75% Grass cover, Good PR1, PR2, PR3 0.000 1.935 0.000 0.000 0.000 1.935 Paved parking PR1, PR2, PR3 0.000 6.064 0.000 0.000 0.000 6.064 TOTAL AREA 21361 PROPOSED Prepared by Civil Site Group Printed 4/5/2024 HydroCAD®10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 6 Pipe Listing (all nodes) Line# Node In-Invert Out-Invert Length Slope n Width Diam/Height Inside-Fill Node Number (feet) (feet) (feet) (ft/ft) (inches) (inches) (inches) Name 1 2P 926.59 922.00 459.0 0.0100 0.013 0.0 24.0 0.0 2 3P 924.60 922.00 130.0 0.0200 0.013 0.0 12.0 0.0 21361 PROPOSED MSE 24-hr 3 2y 24hrAT-14 Rainfall=2.94" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD® 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 7 Time span=0.00-240.00 hrs, dt=0.01 hrs, 24001 points Runoff by SCS TR-20 method, UH=SCS, Weighted-Q Reach routing by Stor-Ind method - Pond routing by Stor-Ind method SubcatchmentPR1: PR1 (TO EXISTING Runoff Area=113,708 sf 0.37% Impervious Runoff Depth=0.35" Tc=6.0 min CN=WQ Runoff=1.16 cfs 0.076 of SubcatchmentPR2: PR2(DRAINS TO 2P) Runoff Area=99,660 sf 49.93% Impervious Runoff Depth=1.52" Tc=6.0 min CN=WQ Runoff=5.40 cfs 0.291 af SubcatchmentPR3: PR3(DRAINS TO 3P) Runoff Area=50,775 sf 67.14% Impervious Runoff Depth=1.93" Tc=6.0 min CN=WQ Runoff=3.54 cfs 0.188 af Reach 2R: EXISTING POND Inflow=6.13 cfs 0.555 af Outflow=6.13 cfs 0.555 af Pond 2P: 2P-ABOVEGROUNDFILTRATION Peak Elev=934.44' Storage=3,528 cf Inflow=5.40 cfs 0.291 af Outflow=4.88 cfs 0.291 af Pond 3P: UNDERGROUND FILTRATION Peak EIev=930.70' Storage=4,789 cf Inflow=3.54 cfs 0.188 af Outflow=0.10 cfs 0.188 af Total Runoff Area = 6.064 ac Runoff Volume = 0.555 af Average Runoff Depth = 1.10" 68.09% Pervious = 4.129 ac 31.91% Impervious = 1.935 ac 21361 PROPOSED MSE 24-hr 3 2y 24hr AT-14 Rainfall=2.94" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD® 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 8 Summary for Subcatchment PRI: PRI (TO EXISTING POND) Runoff = 1.16 cfs @ 12.15 hrs, Volume= 0.076 af, Depth= 0.35" Routed to Reach 2R : EXISTING POND Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-240.00 hrs, dt= 0.01 hrs MSE 24-hr 3 2y 24hr AT-14 Rainfall=2.94" Area (sf) CN Description 424 98 Paved parking, HSG B 113,284 61 >75% Grass cover, Good, HSG B 113,708 Weighted Average 113,284 99.63% Pervious Area 424 0.37% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PRI: PRI (TO EXISTING POND) Hydrograph ❑Runoff 11.16 cfs I r MSE 24-hr 3 2y 24hr AT-14 Rainfall=2.94" / Runoff Area=113,708 sf Runoff Volume=0.076 af Runoff Depth=0.35" Tc=6.0 min CN=WQ II o 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 Time (hours) 21361 PROPOSED MSE 24-hr 3 2y 24hr AT-14 Rainfall=2.94" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD© 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 9 Summary for Subcatchment PR2: PR2 (DRAINS TO 2P) Runoff = 5.40 cfs @ 12.13 hrs, Volume= 0.291 af, Depth= 1.52" Routed to Pond 2P : 2P -ABOVEGROUND FILTRATION BASIN Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-240.00 hrs, dt= 0.01 hrs MSE 24-hr 3 2y 24hr AT-14 Rainfall=2.94" Area (sf) CN Description 49,764 98 Paved parking, HSG B 49,896 61 >75% Grass cover, Good, HSG B 99,660 Weighted Average 49,896 50.07% Pervious Area 49,764 49.93% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR2: PR2 (DRAINS TO 2P) Hydrograph 6- 0 Runoff - 15 40 cfs I MSE 24-hr 3 5- 2y 24hr AT-14 Rainfall=2.94" Runoff Area=99,660 sf 4- Runoff Volume=0.291 af - Runoff Depth=1.52" 3- Tc=6.0 min - 0 CN=WQ 2 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 Time (hours) 21361 PROPOSED MSE 24-hr 3 2y 24hr AT-14 Rainfall=2.94" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD® 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 10 Summary for Subcatchment PR3: PR3 (DRAINS TO 3P) Runoff = 3.54 cfs @ 12.13 hrs, Volume= 0.188 af, Depth= 1.93" Routed to Pond 3P : UNDERGROUND FILTRATION BASIN Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-240.00 hrs, dt= 0.01 hrs MSE 24-hr 3 2y 24hr AT-14 Rainfall=2.94" Area (sf) CN Description 34,089 98 Paved parking, HSG B 16,686 61 >75% Grass cover, Good, HSG B 50,775 Weighted Average 16,686 32.86% Pervious Area 34,089 67.14% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR3: PR3 (DRAINS TO 3P) Hydrograph z 0 Runoff 13.54 cfs I MSE 24-hr 3 - / 2y 24hr AT-14 Rainfall=2.94" 3- / Runoff Area=50,775 sf Runoff Volume=0.188 of y f Runoff Depth=1.93" 2- / Tc=6.0 min CN=WQ 1- 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190'200 210 220 230 240 Time (hours) 21361 PROPOSED MSE 24-hr 3 2y 24hrAT-14 Rainfal1=2.94" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD®10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 11 Summary for Reach 2R: EXISTING POND [40] Hint: Not Described (Outflow=lnflow) Inflow Area = 6.064 ac, 31.91% Impervious, Inflow Depth = 1.10" for 2y 24hr AT-14 event Inflow = 6.13 cfs @ 12.16 hrs, Volume= 0.555 af Outflow = 6.13 cfs @ 12.16 hrs, Volume= 0.555 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 0.00-240.00 hrs, dt= 0.01 hrs Reach 2R: EXISTING POND Hydrograph ®Inflow 1 6.73 cfs I__. El Outflow - 61 3 Inflow Area=6.064 ac 5_ 3 4- u_ 3- I 1 I $, if 0- . //«/ / //// / '/�///./ 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 Time (hours) 21361 PROPOSED MSE 24-hr 3 2y 24hrAT-14 Rainfall=2.94" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD© 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 12 Summary for Pond 2P: 2P - ABOVEGROUND FILTRATION BASIN Inflow Area = 2.288 ac, 49.93% Impervious, Inflow Depth = 1.52" for 2y 24hr AT-14 event Inflow = 5.40 cfs @ 12.13 hrs, Volume= 0.291 af Outflow = 4.88 cfs @ 12.16 hrs, Volume= 0.291 af, Atten= 10%, Lag= 1.7 min Primary = 4.88 cfs @ 12.16 hrs, Volume= 0.291 af Routed to Reach 2R : EXISTING POND Routing by Stor-Ind method, Time Span= 0.00-240.00 hrs, dt= 0.01 hrs Peak Elev= 934.44'@ 12.16 hrs Surf.Area= 2,235 sf Storage= 3,528 cf Plug-Flow detention time=204.7 min calculated for 0.291 af(100% of inflow) Center-of-Mass det. time=204.7 min ( 972.0- 767.3 ) Volume Invert Avail.Storage Storage Description #1 932.00' 10,971 cf Custom Stage Data (Prismaticiisted below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 932.00 647 0 0 933.00 1,293 970 970 933.84 1,855 1,322 2,292 934.84 2,483 2,169 4,461 935.84 3,174 2,829 7,290 936.84 4,188 3,681 10,971 Device Routing Invert Outlet Devices #1 Primary 935.80' 10.0' long x 5.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.34 2.50 2.70 2.68 2.68 2.66 2.65 2.65 2.65 2.65 2.67 2.66 2.68 2.70 2.74 2.79 2.88 #2 Device 5 934.00' 53.0"W x 53.0" H 30° Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 4 932.00' 1.600 in/hr Exfiltration over Surface area #4 Device 5 930.00' 6.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #5 Primary 926.59' 24.0" Round Culvert L=459.0' CMP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 926.59'/922.00' S= 0.0100'/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max=4.87 cfs @ 12.16 hrs HW=934.44' (Free Discharge) 1=Broad-Crested Rectangular Weir( Controls 0.00 cfs) =Culvert (Passes 4.87 cfs of 30.32 cfs potential flow) t2=Orifice/Grate (Weir Controls 4.79 cfs @ 2.08 fps) 4=Orifice/Grate (Passes 0.08 cfs of 1.94 cfs potential flow) 4---3=Exfiltration (Exfiltration Controls 0.08 cfs) 21361 PROPOSED MSE 24-hr 3 2y 24hrAT-14 Rainfal1=2.94" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD® 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 13 Pond 2P: 2P - ABOVEGROUND FILTRATION BASIN Hydrograph 6_/ G'Inflow I s.40crs l ❑Primary Inflow Area=2.288 ac 5- 1488ds Peak Elev=934.44' 4- Storage=3,528 cf 0 3- LL - 2— f'. 1— - 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 Time (hours) 21361 PROPOSED MSE 24-hr 3 2y 24hrAT-14 Rainfall=2.94" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD® 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 14 Stage-Area-Storage for Pond 2P: 2P -ABOVEGROUND FILTRATION BASIN Elevation Surface Storage Elevation Surface Storage (feet) (sq-ft) (cubic-feet) (feet) (sq-ft) (cubic-feet) 932.00 647 0 934.60 2,332 3,883 932.05 679 33 934.65 2,364 4,001 932.10 712 68 934.70 2,395 4,120 932.15 744 104 934.75 2,426 4,240 932.20 776 142 934.80 2,458 4,362 932.25 809 182 934.85 2,490 4,486 932.30 841 223 934.90 2,524 4,611 932.35 873 266 934.95 2,559 4,738 932.40 905 310 935.00 2,594 4,867 932.45 938 357 935.05 2,628 4,998 932.50 970 404 935.10 2,663 5,130 932.55 1,002 454 935.15 2,697 5,264 932.60 1,035 504 935.20 2,732 5,400 932.65 1,067 557 935.25 2,766 5,537 932.70 1,099 611 935.30 2,801 5,676 932.75 1,132 667 935.35 2,835 5,817 932.80 1,164 724 935.40 2,870 5,960 932.85 1,196 783 935.45 2,905 6,104 932.90 1,228 844 935.50 2,939 6,250 932.95 1,261 906 935.55 2,974 6,398 933.00 1,293 970 935.60 3,008 6,548 933.05 1,326 1,035 935.65 3,043 6,699 933.10 1,360 1,103 935.70 3,077 6,852 933.15 1,393 1,171 935.75 3,112 7,007 933.20 1,427 1,242 935.80 3,146 7,163 933.25 1,460 1,314 935.85 3,184 7,321 933.30 1,494 1,388 935.90 3,235 7,482 933.35 1,527 1,464 935.95 3,286 7,645 933.40 1,561 1,541 936.00 3,336 7,810 933.45 1,594 1,620 936.05 3,387 7,979 933.50 1,628 1,700 936.10 3,438 8,149 933.55 1,661 1,782 936.15 3,488 8,322 933.60 1,694 1,866 936.20 3,539 8,498 933.65 1,728 1,952 936.25 3,590 8,676 933.70 1,761 2,039 936.30 3,640 8,857 933.75 1,795 2,128 936.35 3,691 9,040 933.80 1,828 2,218 936.40 3,742 9,226 933.85 1,861 2,311 936.45 3,793 9,414 933.90 1,893 2,405 936.50 3,843 9,605 933.95 1,924 2,500 936.55 3,894 9,799 934.00 1,955 2,597 936.60 3,945 9,995 934.05 1,987 2,696 936.65 3,995 10,193 934.10 2,018 2,796 936.70 4,046 10,394 934.15 2,050 2,897 936.75 4,097 10,598 934.20 2,081 3,001 936.80 4,147 10,804 934.25 2,112 3,105 934.30 2,144 3,212 934.35 2,175 3,320 934.40 2,207 3,429 934.45 2,238 3,541 934.50 2,269 3,653 934.55 2,301 3,767 21361 PROPOSED MSE 24-hr 3 2y 24hrAT-14 Rainfall=2.94" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD© 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 15 Summary for Pond 3P: UNDERGROUND FILTRATION BASIN Inflow Area = 1.166 ac, 67.14% Impervious, Inflow Depth = 1.93" for 2y 24hr AT-14 event Inflow = 3.54 cfs @ 12.13 hrs, Volume= 0.188 af Outflow = 0.10 cfs @ 10.72 hrs, Volume= 0.188 af, Atten= 97%, Lag= 0.0 min Primary = 0.10 cfs @ 10.72 hrs, Volume= 0.188 af Routed to Reach 2R : EXISTING POND Routing by Stor-Ind method, Time Span= 0.00-240.00 hrs, dt= 0.01 hrs Peak Elev= 930.70'@ 13.69 hrs Surf.Area= 2,796 sf Storage= 4,789 cf Plug-Flow detention time=405.1 min calculated for 0.188 of(100% of inflow) Center-of-Mass det. time=405.1 min ( 1,165.7- 760.5 ) Volume Invert Avail.Storage Storage Description #1A 928.00' 3,504 cf 31.73W x 88.12'L x 6.06'H Field A 16,941 cf Overall- 8,182 cf Embedded= 8,759 cf x 40.0%Voids #2A 928.00' 6,988 cf Prinsco Dual-Wall 60"x 12 Inside#1 Inside= 59.7"W x 59.7"H => 19.44 sf x 20.00'L = 388.8 cf Outside= 66.7"W x 66.7"H => 22.75 sf x 20.00'L = 455.0 cf Row Length Adjustment= +15.00' x 19.44 sf x 4 rows 29.73' Header x 19.44 sf x 2 = 1,156.0 cf Inside 10,491 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Device 4 931.50' 18.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Device 3 928.00' 1.600 in/hr Exfiltration over Surface area #3 Primary 926.00' 6.0" Veil. Orifice/Grate C= 0.600 Limited to weir flow at low heads #4 Primary 924.60' 12.0" Round Culvert L= 130.0' CMP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 924.60'/ 922.00' S= 0.0200 'I' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=0.10 cfs @ 10.72 hrs HW=928.06' (Free Discharge) -3=Orifice/Grate (Passes 0.10 cfs of 1.27 cfs potential flow) L2=Exfiltration (Exfiltration Controls 0.10 cfs) -4=Culvert (Passes 0.00 cfs of 6.00 cfs potential flow) L1=Orifice/Grate ( Controls 0.00 cfs) 21361 PROPOSED MSE 24-hr 3 2y 24hrAT-14 Rainfall=2.94" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD® 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 16 Pond 3P: UNDERGROUND FILTRATION BASIN - Chamber Wizard Field A Chamber Model= Prinsco Dual-Wall 60"(Prinsco GoldFlo®,GoldFlo WT®, EcoFlo®100,GoldPro Storm pipe) Inside= 59.7"W x 59.7"H => 19.44 sf x 20.00'L = 388.8 cf Outside= 66.7"W x 66.7"H => 22.75 sf x 20.00'L= 455.0 cf Row Length Adjustment= +15.00'x 19.44 sf x 4 rows 66.7"Wide + 30.0" Spacing = 96.7" C-C Row Spacing 3 Chambers/Row x 20.00' Long +15.00' Row Adjustment+5.56' Header x 2 = 86.12' Row Length +12.0" End Stone x 2 = 88.12' Base Length 4 Rows x 66.7"Wide + 30.0" Spacing x 3 + 12.0" Side Stone x 2 = 31.73' Base Width 66.7" Chamber Height + 6.0" Stone Cover= 6.06' Field Height 12 Chambers x 388.8 cf +15.00' Row Adjustment x 19.44 sf x 4 Rows+ 29.73' Header x 19.44 sf x 2 = 6,987.7 cf Chamber Storage 12 Chambers x 455.0 cf +15.00' Row Adjustment x 22.75 sf x 4 Rows + 29.73' Header x 22.75 sf x 2 = 8,178.2 cf Displacement 16,940.5 cf Field - 8,178.2 cf Chambers= 8,762.4 cf Stone x 40.0%Voids = 3,504.9 cf Stone Storage Chamber Storage + Stone Storage= 10,492.7 cf= 0.241 of Overall Storage Efficiency = 61.9% Overall System Size= 88.12' x 31.73'x 6.06' 12 Chambers 627.4 cy Field 324.5 cy Stone ) 0 0 21361 PROPOSED MSE 24-hr 3 2y 24hrAT-14 Rainfall=2.94" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD® 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 17 Pond 3P: UNDERGROUND FILTRATION BASIN Hydrograph Inflow I3.54crs I 0 Primary Inflow Area=1 .166 ac Peak Elev=930.70' Storage=4,789 cf 2 LL 1- _ ® 0 /////, 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190200 210 220 230 240 Time (hours) 21361 PROPOSED MSE 24-hr 3 2y 24hrAT-14 Rainfall=2.94" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD© 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 18 Stage-Area-Storage for Pond 3P: UNDERGROUND FILTRATION BASIN Elevation Surface Storage Elevation Surface Storage (feet) (sq-ft) (cubic-feet) (feet) (sq-ft) (cubic-feet) 928.00 2,796 0 933.20 2,796 9,602 928.10 2,796 99 933.30 2,796 9,698 928.20 2,796 186 933.40 2,796 9,781 928.30 2,796 268 933.50 2,796 9,873 928.40 2,796 380 933.60 2,796 9,979 928.50 2,796 514 933.70 2,796 10,090 928.60 2,796 660 933.80 2,796 10,202 928.70 2,796 816 933.90 2,796 10,314 928.80 2,796 980 934.00 2,796 10,426 928.90 2,796 1,151 929.00 2,796 1,328 929.10 2,796 1,509 929.20 2,796 1,695 929.30 2,796 1,886 929.40 2,796 2,080 929.50 2,796 2,277 929.60 2,796 2,477 929.70 2,796 2,680 929.80 2,796 2,885 929.90 2,796 3,092 930.00 2,796 3,301 930.10 2,796 3,511 930.20 2,796 3,723 930.30 2,796 3,936 930.40 2,796 4,150 930.50 2,796 4,364 930.60 2,796 4,580 930.70 2,796 4,795 930.80 2,796 5,011 930.90 2,796 5,227 931.00 2,796 5,442 931.10 2,796 5,657 931.20 2,796 5,871 931.30 2,796 6,085 931.40 2,796 6,298 931.50 2,796 6,509 931.60 2,796 6,719 931.70 2,796 6,927 931.80 2,796 7,133 931.90 2,796 7,337 932.00 2,796 7,539 932.10 2,796 7,738 932.20 2,796 7,934 932.30 2,796 8,126 932.40 2,796 8,315 932.50 2,796 8,499 932.60 2,796 8,679 932.70 2,796 8,853 932.80 2,796 9,021 932.90 2,796 9,182 933.00 2,796 9,334 933.10 2,796 9,476 21361 PROPOSED MSE 24-hr 3 10y 24hrAT-14 Rainfall=4.47" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD© 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 19 Time span=0.00-240.00 hrs, dt=0.01 hrs, 24001 points Runoff by SCS TR-20 method, UH=SCS, Weighted-Q Reach routing by Stor-Ind method - Pond routing by Stor-Ind method SubcatchmentPR1: PR1 (TO EXISTING Runoff Area=113,708 sf 0.37% Impervious Runoff Depth=1.07" Tc=6.0 min CN=WQ Runoff=4.92 cfs 0.234 af SubcatchmentPR2: PR2(DRAINS TO 2P) Runoff Area=99,660 sf 49.93% Impervious Runoff Depth=2.65" Tc=6.0 min CN=WQ Runoff=9.69 cfs 0.505 af SubcatchmentPR3: PR3(DRAINSTO 3P) Runoff Area=50,775 sf 67.14% Impervious Runoff Depth=3.19" Tc=6.0 min CN=WQ Runoff=5.90 cfs 0.310 af Reach 2R: EXISTING POND Inflow=13.99 cfs 1.048 af Outflow=13.99 cfs 1.048 af Pond 2P: 2P-ABOVEGROUNDFILTRATION Peak Elev=934.65' Storage=4,002 cf Inflow=9.69 cfs 0.505 af Outflow=9.05 cfs 0.505 af Pond 3P: UNDERGROUND FILTRATION Peak Elev=931.83' Storage=7,188 cf Inflow=5.90 cfs 0.310 af Outflow=0.66 cfs 0.310 af Total Runoff Area = 6.064 ac Runoff Volume = 1.048 af Average Runoff Depth = 2.07" 68.09% Pervious = 4.129 ac 31.91% Impervious = 1.935 ac 21361 PROPOSED MSE 24-hr 3 10y 24hrAT-14 Rainfall=4.47" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD® 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 20 Summary for Subcatchment PRI: PRI (TO EXISTING POND) Runoff = 4.92 cfs @ 12.14 hrs, Volume= 0.234 af, Depth= 1.07" Routed to Reach 2R : EXISTING POND Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-240.00 hrs, dt= 0.01 hrs MSE 24-hr 3 10y 24hr AT-14 Rainfall=4.47" Area (sf) CN Description 424 98 Paved parking, HSG B 113,284 61 >75% Grass cover, Good, HSG B 113,708 Weighted Average 113,284 99.63% Pervious Area 424 0.37% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PRI: PRI (TO EXISTING POND) Hydrograph El Runoff 5 14.92�I MSE 24-hr 3 10y 24hr AT-14 Rainfall=4.47" 4- Runoff Area=113,708 sf Runoff Volume=0.234 of Runoff Depth=1.07" 3- Tc=6.0 min LL CN=WQ - 2- - 1 meg 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 Time (hours) 21361 PROPOSED MSE 24-hr 3 10y 24hr AT-14 Rainfall=4.47" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD® 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 21 Summary for Subcatchment PR2: PR2 (DRAINS TO 2P) Runoff = 9.69 cfs @ 12.13 hrs, Volume= 0.505 af, Depth= 2.65" Routed to Pond 2P : 2P -ABOVEGROUND FILTRATION BASIN Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-240.00 hrs, dt= 0.01 hrs MSE 24-hr 3 10y 24hr AT-14 Rainfall=4.47" Area (sf) CN Description 49,764 98 Paved parking, HSG B 49,896 61 >75% Grass cover, Good, HSG B 99,660 Weighted Average 49,896 50.07% Pervious Area 49,764 49.93% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR2: PR2 (DRAINS TO 2P) Hydrograph ❑Runoff 10— 1 9.69 cfs f MSE 24-hr 3 10y 24hr AT-14 Rainfall=4.47" 8- 1 Runoff Area=99,660 sf 7_ Runoff Volume=0.505 af Runoff Depth=2.65" 6 / Tc=6.0 min 5= CN=WQ 4- 2- / 0 - f��'��������������������������������������'��f���f����������������������j�����������������f� 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220'230 240 Time (hours) 21361 PROPOSED MSE 24-hr 3 10y 24hr AT-14 Rainfall=4.47" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD® 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 22 Summary for Subcatchment PR3: PR3 (DRAINS TO 3P) Runoff = 5.90 cfs @ 12.13 hrs, Volume= 0.310 af, Depth= 3.19" Routed to Pond 3P : UNDERGROUND FILTRATION BASIN Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-240.00 hrs, dt= 0.01 hrs MSE 24-hr 3 10y 24hr AT-14 Rainfall=4.47" Area (sf) CN Description 34,089 98 Paved parking, HSG B 16,686 61 >75% Grass cover, Good, HSG B 50,775 Weighted Average 16,686 32.86% Pervious Area 34,089 67.14% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR3: PR3 (DRAINS TO 3P) / Hydrograph m Runoff 6 ® MSE 24-hr 3 10y 24hr AT-14 Rainfall=4.47" 5= Runoff Area=50,775 sf Runoff Volume=0.310 af 4- Runoff Depth=3.19" Tc=6.0 min ° 3- CN=WQ 2_ • O o ds, . 07zz,e r .. -,wwzzm ' 1���/,,Ofg:4,e: /1 atr/ e-y-w-m- 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 Time (hours) 21361 PROPOSED MSE 24-hr 3 10y 24hr AT-14 Rainfall=4.47" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD®10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 23 Summary for Reach 2R: EXISTING POND [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 6.064 ac, 31.91% Impervious, Inflow Depth = 2.07" for 10y 24hr AT-14 event Inflow = 13.99 cfs @ 12.15 hrs, Volume= 1.048 of Outflow = 13.99 cfs @ 12.15 hrs, Volume= 1.048 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 0.00-240.00 hrs, dt= 0.01 hrs Reach 2R: EXISTING POND Hydrograph • Inflow 15— 113.99 c6 F X1399 cfs Inflow Area=6.064 ac 14: 13- 12= 11. 10= 04 w 9_ 7z, PY- 6_ 5_ f 4 V 2 A 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 Time (hours) 21361 PROPOSED MSE 24-hr 3 10y 24hrAT-14 Rainfall=4.47" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD® 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 24 Summary for Pond 2P: 2P - ABOVEGROUND FILTRATION BASIN Inflow Area = 2.288 ac, 49.93% Impervious, Inflow Depth = 2.65" for 10y 24hr AT-14 event Inflow = 9.69 cfs @ 12.13 hrs, Volume= 0.505 af Outflow = 9.05 cfs @ 12.16 hrs, Volume= 0.505 af, Atten= 7%, Lag= 1.4 min Primary = 9.05 cfs @ 12.16 hrs, Volume= 0.505 af Routed to Reach 2R : EXISTING POND Routing by Stor-Ind method, Time Span= 0.00-240.00 hrs, dt= 0.01 hrs Peak Elev= 934.65'@ 12.16 hrs Surf.Area= 2,364 sf Storage= 4,002 cf Plug-Flow detention time= 139.3 min calculated for 0.505 of(100% of inflow) Center-of-Mass det. time= 139.3 min ( 905.3 -766.0 ) Volume Invert Avail.Storage Storage Description #1 932.00' 10,971 cf Custom Stage Data (Prismatic)Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 932.00 647 0 0 933.00 1,293 970 970 933.84 1,855 1,322 2,292 934.84 2,483 2,169 4,461 935.84 3,174 2,829 7,290 936.84 4,188 3,681 10,971 Device Routing Invert Outlet Devices #1 Primary 935.80' 10.0' long x 5.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.34 2.50 2.70 2.68 2.68 2.66 2.65 2.65 2.65 2.65 2.67 2.66 2.68 2.70 2.74 2.79 2.88 #2 Device 5 934.00' 53.0"W x 53.0" H 30° Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 4 932.00' 1.600 in/hr Exfiltration over Surface area #4 Device 5 930.00' 6.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #5 Primary 926.59' 24.0" Round Culvert L=459.0' CMP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 926.59'/922.00' S= 0.0100 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max=9.02 cfs @ 12.16 hrs HW=934.65' (Free Discharge) 1=Broad-Crested Rectangular Weir( Controls 0.00 cfs) =Culvert (Passes 9.02 cfs of 30.62 cfs potential flow) 2=Orifice/Grate (Weir Controls 8.93 cfs @ 2.48 fps) =Orifice/Grate (Passes 0.09 cfs of 1.98 cfs potential flow) L3=Exfiltration (Exfiltration Controls 0.09 cfs) 21361 PROPOSED MSE 24-hr 3 10y 24hrAT-14 Rainfall=4.47" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD© 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 25 Pond 2P: 2P -ABOVEGROUND FILTRATION BASIN Hydrograph IN inflow 1969. cfs( Primary 10_ l Inflow Area=2:28&-ac 1905. cfs 9 Peak EIev=934.65' 8_ Storage=4,002 cf 7- F. 6- 3 - _! 0 5 4 3- 2- 1- 0 � 1f � r�� rg,,, ✓'f/'.1`l `vtf� f`i �l�l .�lff � 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 Time (hours) 21361 PROPOSED MSE 24-hr 3 10y 24hr AT-14 Rainfall=4.47" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD© 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 26 Stage-Area-Storage for Pond 2P: 2P -ABOVEGROUND FILTRATION BASIN Elevation Surface Storage Elevation Surface Storage (feet) (sq-ft) (cubic-feet) (feet) (sq-ft) (cubic-feet) 932.00 647 0 934.60 2,332 3,883 932.05 679 33 934.65 2,364 4,001 932.10 712 68 934.70 2,395 4,120 932.15 744 104 934.75 2,426 4,240 932.20 776 142 934.80 2,458 4,362 932.25 809 182 934.85 2,490 4,486 932.30 841 223 934.90 2,524 4,611 932.35 873 266 934.95 2,559 4,738 932.40 905 310 935.00 2,594 4,867 932.45 938 357 935.05 2,628 4,998 932.50 970 404 935.10 2,663 5,130 932.55 1,002 454 935.15 2,697 5,264 932.60 1,035 504 935.20 2,732 5,400 932.65 1,067 557 935.25 2,766 5,537 932.70 1,099 611 935.30 2,801 5,676 932.75 1,132 667 935.35 2,835 5,817 932.80 1,164 724 935.40 2,870 5,960 932.85 1,196 783 935.45 2,905 6,104 932.90 1,228 844 935.50 2,939 6,250 932.95 1,261 906 935.55 2,974 6,398 933.00 1,293 970 935.60 3,008 6,548 933.05 1,326 1,035 935.65 3,043 6,699 933.10 1,360 1,103 935.70 3,077 6,852 933.15 1,393 1,171 935.75 3,112 7,007 933.20 1,427 1,242 935.80 3,146 7,163 933.25 1,460 1,314 935.85 3,184 7,321 933.30 1,494 1,388 935.90 3,235 7,482 933.35 1,527 1,464 935.95 3,286 7,645 933.40 1,561 1,541 936.00 3,336 7,810 933.45 1,594 1,620 936.05 3,387 7,979 933.50 1,628 1,700 936.10 3,438 8,149 933.55 1,661 1,782 936.15 3,488 8,322 933.60 1,694 1,866 936.20 3,539 8,498 933.65 1,728 1,952 936.25 3,590 8,676 933.70 1,761 2,039 936.30 3,640 8,857 933.75 1,795 2,128 936.35 3,691 9,040 933.80 1,828 2,218 936.40 3,742 9,226 933.85 1,861 2,311 936.45 3,793 9,414 933.90 1,893 2,405 936.50 3,843 9,605 933.95 1,924 2,500 936.55 3,894 9,799 934.00 1,955 2,597 936.60 3,945 9,995 934.05 1,987 2,696 936.65 3,995 10,193 934.10 2,018 2,796 936.70 4,046 10,394 934.15 2,050 2,897 936.75 4,097 10,598 934.20 2,081 3,001 936.80 4,147 10,804 934.25 2,112 3,105 934.30 2,144 3,212 934.35 2,175 3,320 934.40 2,207 3,429 934.45 2,238 3,541 934.50 2,269 3,653 934.55 2,301 3,767 21361 PROPOSED MSE 24-hr 3 10y 24hrAT-14 Rainfall=4.47" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD© 10.20-4a sin 02202 ©2023 HydroCAD Software Solutions LLC Page 27 Summary for Pond 3P: UNDERGROUND FILTRATION BASIN Inflow Area = 1.166 ac, 67.14% Impervious, Inflow Depth = 3.19" for 10y 24hr AT-14 event Inflow = 5.90 cfs @ 12.13 hrs, Volume= 0.310 af Outflow = 0.66 cfs @ 12.59 hrs, Volume= 0.310 af, Atten= 89%, Lag= 27.5 min Primary = 0.66 cfs © 12.59 hrs, Volume= 0.310 af Routed to Reach 2R : EXISTING POND Routing by Stor-Ind method, Time Span= 0.00-240.00 hrs, dt= 0.01 hrs Peak Elev= 931.83'@ 12.59 hrs Surf.Area= 2,796 sf Storage= 7,188 cf Plug-Flow detention time=481.0 min calculated for 0.310 af(100% of inflow) Center-of-Mass det. time=481.0 min ( 1,238.2 - 757.2 ) Volume Invert Avail.Storage Storage Description #1A 928.00' 3,504 cf 31.73W x 88.12'L x 6.06'H Field A 16,941 cf Overall- 8,182 cf Embedded= 8,759 cf x 40.0% Voids #2A 928.00' 6,988 cf Prinsco Dual-Wall 60"x 12 Inside#1 Inside= 59.7"W x 59.7"H => 19.44 sf x 20.00'L = 388.8 cf Outside= 66.7"W x 66.7"H => 22.75 sf x 20.00'L = 455.0 cf Row Length Adjustment= +15.00' x 19.44 sf x 4 rows 29.73' Header x 19.44 sf x 2 = 1,156.0 cf Inside 10,491 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Device 4 931.50' 18.0"Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Device 3 928.00' 1.600 in/hr Exfiltration over Surface area #3 Primary 926.00' 6.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #4 Primary 924.60' 12.0" Round Culvert L= 130.0' CMP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 924.60'/922.00' S= 0.0200 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=0.66 cfs @ 12.59 hrs HW=931.83' (Free Discharge) 3=Orifice/Grate (Passes 0.10 cfs of 2.23 cfs potential flow) L2=Exfiltration (Exfiltration Controls 0.10 cfs) 4=Culvert (Passes 0.55 cfs of 7.93 cfs potential flow) L1=Orifice/Grate (Orifice Controls 0.55 cfs @ 1.95 fps) 21361 PROPOSED MSE 24-hr 3 10y 24hrAT-14 Rainfall=4.47" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD® 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 28 Pond 3P: UNDERGROUND FILTRATION BASIN - Chamber Wizard Field A Chamber Model= Prinsco Dual-Wall 60"(Prinsco GoldFlo®,GoldFlo WT®, EcoFlo®100,GoldPro Storm pipe) Inside= 59.7"W x 59.7"H => 19.44 sf x 20.00'L = 388.8 cf Outside= 66.7"W x 66.7"H => 22.75 sf x 20.00'L= 455.0 cf Row Length Adjustment= +15.00'x 19.44 sf x 4 rows 66.7" Wide + 30.0" Spacing = 96.7" C-C Row Spacing 3 Chambers/Row x 20.00' Long +15.00' Row Adjustment+5.56' Header x 2 = 86.12' Row Length +12.0" End Stone x 2 = 88.12' Base Length 4 Rows x 66.7" Wide + 30.0" Spacing x 3 + 12.0" Side Stone x 2 = 31.73' Base Width 66.7" Chamber Height + 6.0" Stone Cover = 6.06' Field Height 12 Chambers x 388.8 cf +15.00' Row Adjustment x 19.44 sf x 4 Rows + 29.73' Header x 19.44 sf x 2 = 6,987.7 cf Chamber Storage 12 Chambers x 455.0 cf +15.00' Row Adjustment x 22.75 sf x 4 Rows + 29.73' Header x 22.75 sf x 2 = 8,178.2 cf Displacement 16,940.5 cf Field - 8,178.2 cf Chambers = 8,762.4 cf Stone x 40.0%Voids = 3,504.9 cf Stone Storage Chamber Storage + Stone Storage= 10,492.7 cf= 0.241 of Overall Storage Efficiency = 61.9% Overall System Size= 88.12'x 31.73'x 6.06' 12 Chambers 627.4 cy Field 324.5 cy Stone . ) 0OC 21361 PROPOSED MSE 24-hr 3 10y 24hrAT-14 Rainfall=4.47" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD® 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 29 Pond 3P: UNDERGROUND FILTRATION BASIN Hydrograph / ■Inflow I s.90 cfs( p Primary Inflow Area=1 .166 ac Peak EIev=931 .83' Storage=7,188 cf_ 4- (0 • 0 3- u_ - 2- 1- 10.66Cfs 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 Time (hours) 21361 PROPOSED MSE 24-hr 3 10y 24hr AT-14 Rainfall=4.47" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD® 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 30 Stage-Area-Storage for Pond 3P: UNDERGROUND FILTRATION BASIN Elevation Surface Storage Elevation Surface Storage (feet) (sq-ft) (cubic-feet) (feet) (sq-ft) (cubic-feet) 928.00 2,796 0 933.20 2,796 9,602 928.10 2,796 99 933.30 2,796 9,698 928.20 2,796 186 933.40 2,796 9,781 928.30 2,796 268 933.50 2,796 9,873 928.40 2,796 380 933.60 2,796 9,979 928.50 2,796 514 933.70 2,796 10,090 928.60 2,796 660 933.80 2,796 10,202 928.70 2,796 816 933.90 2,796 10,314 928.80 2,796 980 934.00 2,796 10,426 928.90 2,796 1,151 929.00 2,796 1,328 929.10 2,796 1,509 929.20 2,796 1,695 929.30 2,796 1,886 929.40 2,796 2,080 929.50 2,796 2,277 929.60 2,796 2,477 929.70 2,796 2,680 929.80 2,796 2,885 929.90 2,796 3,092 930.00 2,796 3,301 930.10 2,796 3,511 930.20 2,796 3,723 930.30 2,796 3,936 930.40 2,796 4,150 930.50 2,796 4,364 930.60 2,796 4,580 930.70 2,796 4,795 930.80 2,796 5,011 930.90 2,796 5,227 931.00 2,796 5,442 931.10 2,796 5,657 931.20 2,796 5,871 931.30 2,796 6,085 931.40 2,796 6,298 931.50 2,796 6,509 931.60 2,796 6,719 931.70 2,796 6,927 931.80 2,796 7,133 931.90 2,796 7,337 932.00 2,796 7,539 932.10 2,796 7,738 932.20 2,796 7,934 932.30 2,796 8,126 932.40 2,796 8,315 932.50 2,796 8,499 932.60 2,796 8,679 932.70 2,796 8,853 932.80 2,796 9,021 932.90 2,796 9,182 933.00 2,796 9,334 933.10 2,796 9,476 21361 PROPOSED MSE 24-hr 3 100y 24hrAT-14 Rainfall=7.81" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD® 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 31 Time span=0.00-240.00 hrs, dt=0.01 hrs, 24001 points Runoff by SCS TR-20 method, UH=SCS, Weighted-Q Reach routing by Stor-Ind method - Pond routing by Stor-Ind method SubcatchmentPR1: PR1 (TO EXISTING Runoff Area=113,708 sf 0.37% Impervious Runoff Depth=3.32" Tc=6.0 min CN=WQ Runoff=16.14 cfs 0.721 af SubcatchmentPR2: PR2(DRAINS TO 2P) Runoff Area=99,660 sf 49.93% Impervious Runoff Depth=5.43" Tc=6.0 min CN=WQ Runoff=20.36 cfs 1.036 af SubcatchmentPR3: PR3(DRAINS TO 3P) Runoff Area=50,775 sf 67.14% Impervious Runoff Depth=6.17" Tc=6.0 min CN=WQ Runoff=11.48 cfs 0.599 af Reach 2R: EXISTING POND Inflow=42.30 cfs 2.356 af Outflow=42.30 cfs 2.356 af Pond 2P: 2P-ABOVEGROUND Peak EIev=935.02' Storage=4,928 cf Inflow=20.36 cfs 1.036 af Outflow=19.49 cfs 1.036 af Pond 3P: UNDERGROUND FILTRATION Peak EIev=933.09' Storage=9,459 cf Inflow=11.48 cfs 0.599 af Outflow=7.89 cfs 0.599 af Total Runoff Area = 6.064 ac Runoff Volume = 2.356 af Average Runoff Depth = 4.66" 68.09% Pervious = 4.129 ac 31.91% Impervious = 1.935 ac 21361 PROPOSED MSE 24-hr 3 100y 24hr AT-14 Rainfall=7.81" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD© 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 32 Summary for Subcatchment PRI: PRI (TO EXISTING POND) Runoff = 16.14 cfs @ 12.14 hrs, Volume= 0.721 af, Depth= 3.32" Routed to Reach 2R : EXISTING POND Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-240.00 hrs, dt= 0.01 hrs MSE 24-hr 3 100y 24hr AT-14 Rainfall=7.81" Area (sf) CN Description 424 98 Paved parking, HSG B 113,284 61 >75% Grass cover, Good, HSG B 113,708 Weighted Average 113,284 99.63% Pervious Area 424 0.37% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PRI: PRI (TO EXISTING POND) Hydrograph 18_ ---- 0 Runoff 17_ 116.14 cfsl 16. " MSE 24-hr 3 15_ / 100y 24hr AT-14 Rainfall=7.81" 14_ / Runoff Area=113�708 sf 13_ � ,2= / Runoff Volume=0.721 af 11- Runoff Depth=3.32" 10- Tc=6,0 min 9 / CN=WQ 5_ 3= 2 0 a , 4r,d7 mfr 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 Time (hours) 21361 PROPOSED MSE 24-hr 3 100y 24hrAT-14 Rainfall=7.81" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD© 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 34 Summary for Subcatchment PR3: PR3 (DRAINS TO 3P) Runoff = 11.48 cfs @ 12.13 hrs, Volume= 0.599 af, Depth= 6.17" Routed to Pond 3P : UNDERGROUND FILTRATION BASIN Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-240.00 hrs, dt= 0.01 hrs MSE 24-hr 3 100y 24hr AT-14 Rainfall=7.81" Area (sf) CN Description 34,089 98 Paved parking, HSG B 16,686 61 >75% Grass cover, Good, HSG B 50,775 Weighted Average 16,686 32.86% Pervious Area 34,089 67.14% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR3: PR3 (DRAINS TO 3P) Hydrograph 0 Runoff 12-1: 111.48 cfs I MSE 24-hr 3 11 100y 24hr AT-14 Rainfall=7.81-" - 10= Runoff Area=50,775 sf = Runoff Volume=0.599 of 8- Runoff Depth=6.17" 7 c6 - 0min - ---- ----- LL 6- CN=WQ 5_ 4- 3 2- 7 f a 411.- — r r� r as � pr � _ "sem 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 Time (hours) 21361 PROPOSED MSE 24-hr 3 100y 24hr AT-14 Rainfall=7.81" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD® 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 35 Summary for Reach 2R: EXISTING POND [40] Hint: Not Described (Outflow=lnflow) Inflow Area = 6.064 ac, 31.91% Impervious, Inflow Depth = 4.66" for 100y 24hr AT-14 event Inflow = 42.30 cfs @ 12.15 hrs, Volume= 2.356 af Outflow = 42.30 cfs @ 12.15 hrs, Volume= 2.356 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 0.00-240.00 hrs, dt= 0.01 hrs Reach 2R: EXISTING POND Hydrograph ®Inflow 46 ❑Outflow 44_ I42.30cfs Inflow Area=6.064 ac 42_ 40_ 38 36 34 32= 30= 28Vro - u 26 24 0 a 18_ 16= 14= f 12= 10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 Time (hours) 21361 PROPOSED MSE 24-hr 3 100y 24hrAT-14 Rainfall=7.81" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD® 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 36 Summary for Pond 2P: 2P - ABOVEGROUND FILTRATION BASIN Inflow Area = 2.288 ac, 49.93% Impervious, Inflow Depth = 5.43" for 100y 24hr AT-14 event Inflow = 20.36 cfs @ 12.13 hrs, Volume= 1.036 af Outflow = 19.49 cfs @ 12.15 hrs, Volume= 1.036 af, Atten= 4%, Lag= 1.1 min Primary = 19.49 cfs @ 12.15 hrs, Volume= 1.036 af Routed to Reach 2R : EXISTING POND Routing by Stor-Ind method, Time Span= 0.00-240.00 hrs, dt= 0.01 hrs Peak Elev= 935.02'@ 12.15 hrs Surf.Area= 2,610 sf Storage= 4,928 cf Plug-Flow detention time=80.4 min calculated for 1.036 af(100% of inflow) Center-of-Mass det. time=80.3 min ( 843.4 -763.0 ) Volume Invert Avail.Storage Storage Description #1 932.00' 10,971 cf Custom Stage Data (Prismaticpsted below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 932.00 647 0 0 933.00 1,293 970 970 933.84 1,855 1,322 2,292 934.84 2,483 2,169 4,461 935.84 3,174 2,829 7,290 936.84 4,188 3,681 10,971 Device Routing Invert Outlet Devices #1 Primary 935.80' 10.0' long x 5.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.34 2.50 2.70 2.68 2.68 2.66 2.65 2.65 2.65 2.65 2.67 2.66 2.68 2.70 2.74 2.79 2.88 #2 Device 5 934.00' 53.0"W x 53.0" H 30° Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 4 932.00' 1.600 in/hr Exfiltration over Surface area #4 Device 5 930.00' 6.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #5 Primary 926.59' 24.0" Round Culvert L= 459.0' CMP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 926.59'/922.00' S= 0.0100 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max=19.48 cfs @ 12.15 hrs HW=935.02' (Free Discharge) -1=Broad-Crested Rectangular Weir( Controls 0.00 cfs) 5=Culvert (Passes19.48 cfs of 31.15 cfs potential flow) 2=Orifice/Grate (Weir Controls 19.38 cfs @ 3.06 fps) 4=Orifice/Grate (Passes 0.10 cfs of 2.07 cfs potential flow) L3=Exfiltration (Exfiltration Controls 0.10 cfs) 21361 PROPOSED MSE 24-hr 3 100y 24hrAT-14 Rainfall=7.81" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD© 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 37 Pond 2P: 2P - ABOVEGROUND FILTRATION BASIN Hydrograph /- ®Inflow 22' I20.36cfs i 0 Primary 20: 21' Inflow Area=2.288 ac 18- Peak- EIev=935.02` / 4 Storage=4,928 cf 15= 14 13 � F - --- --- 12- 3 11_ o 9- 83 6_ 5= 4' 2 1 �7� // //%/// 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 Time (hours) 21361 PROPOSED MSE 24-hr 3 100y 24hrAT-14 Rainfall=7.81" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD® 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 38 Stage-Area-Storage for Pond 2P: 2P -ABOVEGROUND FILTRATION BASIN Elevation Surface Storage Elevation Surface Storage (feet) (sq-ft) (cubic-feet) (feet) (sq-ft) (cubic-feet) 932.00 647 0 934.60 2,332 3,883 932.05 679 33 934.65 2,364 4,001 932.10 712 68 934.70 2,395 4,120 932.15 744 104 934.75 2,426 4,240 932.20 776 142 934.80 2,458 4,362 932.25 809 182 934.85 2,490 4,486 932.30 841 223 934.90 2,524 4,611 932.35 873 266 934.95 2,559 4,738 932.40 905 310 935.00 2,594 4,867 932.45 938 357 935.05 2,628 4,998 932.50 970 404 935.10 2,663 5,130 932.55 1,002 454 935.15 2,697 5,264 932.60 1,035 504 935.20 2,732 5,400 932.65 1,067 557 935.25 2,766 5,537 932.70 1,099 611 935.30 2,801 5,676 932.75 1,132 667 935.35 2,835 5,817 932.80 1,164 724 935.40 2,870 5,960 932.85 1,196 783 935.45 2,905 6,104 932.90 1,228 844 935.50 2,939 6,250 932.95 1,261 906 935.55 2,974 6,398 933.00 1,293 970 935.60 3,008 6,548 933.05 1,326 1,035 935.65 3,043 6,699 933.10 1,360 1,103 935.70 3,077 6,852 933.15 1,393 1,171 935.75 3,112 7,007 933.20 1,427 1,242 935.80 3,146 7,163 933.25 1,460 1,314 935.85 3,184 7,321 933.30 1,494 1,388 935.90 3,235 7,482 933.35 1,527 1,464 935.95 3,286 7,645 933.40 1,561 1,541 936.00 3,336 7,810 933.45 1,594 1,620 936.05 3,387 7,979 933.50 1,628 1,700 936.10 3,438 8,149 933.55 1,661 1,782 936.15 3,488 8,322 933.60 1,694 1,866 936.20 3,539 8,498 933.65 1,728 1,952 936.25 3,590 8,676 933.70 1,761 2,039 936.30 3,640 8,857 933.75 1,795 2,128 936.35 3,691 9,040 933.80 1,828 2,218 936.40 3,742 9,226 933.85 1,861 2,311 936.45 3,793 9,414 933.90 1,893 2,405 936.50 3,843 9,605 933.95 1,924 2,500 936.55 3,894 9,799 934.00 1,955 2,597 936.60 3,945 9,995 934.05 1,987 2,696 936.65 3,995 10,193 934.10 2,018 2,796 936.70 4,046 10,394 934.15 2,050 2,897 936.75 4,097 10,598 934.20 2,081 3,001 936.80 4,147 10,804 934.25 2,112 3,105 934.30 2,144 3,212 934.35 2,175 3,320 934.40 2,207 3,429 934.45 2,238 3,541 934.50 2,269 3,653 934.55 2,301 3,767 21361 PROPOSED MSE 24-hr 3 100y 24hrAT-14 Rainfall=7.81" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD® 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 39 Summary for Pond 3P: UNDERGROUND FILTRATION BASIN Inflow Area = 1.166 ac, 67.14% Impervious, Inflow Depth = 6.17" for 100y 24hr AT-14 event Inflow = 11.48 cfs @ 12.13 hrs, Volume= 0.599 of Outflow = 7.89 cfs @ 12.19 hrs, Volume= 0.599 af, Atten= 31%, Lag= 3.4 min Primary = 7.89 cfs @ 12.19 hrs, Volume= 0.599 af Routed to Reach 2R : EXISTING POND Routing by Stor-Ind method, Time Span= 0.00-240.00 hrs, dt= 0.01 hrs Peak Elev= 933.09'@ 12.19 hrs Surf.Area= 2,796 sf Storage= 9,459 cf Plug-Flow detention time=300.5 min calculated for 0.599 af(100% of inflow) Center-of-Mass det. time= 300.6 min ( 1,053.8 - 753.3 ) Volume Invert Avail.Storage Storage Description #1A 928.00' 3,504 cf 31.73W x 88.12'L x 6.06'H Field A 16,941 cf Overall- 8,182 cf Embedded= 8,759 cf x 40.0% Voids #2A 928.00' 6,988 cf Prinsco Dual-Wall 60"x 12 Inside#1 Inside= 59.7"W x 59.TH => 19.44 sf x 20.00'L = 388.8 cf Outside= 66.7"W x 66.7"H => 22.75 sf x 20.00'L =455.0 cf Row Length Adjustment= +15.00' x 19.44 sf x 4 rows 29.73' Header x 19.44 sf x 2 = 1,156.0 cf Inside 10,491 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Device 4 931.50' 18.0"Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Device 3 928.00' 1.600 in/hr Exfiltration over Surface area #3 Primary 926.00' 6.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #4 Primary 924.60' 12.0" Round Culvert L= 130.0' CMP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 924.60'/922.00' S= 0.0200'/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf primary OutFlow Max=7.88 cfs @ 12.19 hrs HW=933.09' (Free Discharge) -3=Orifice/Grate (Passes 0.10 cfs of 2.47 cfs potential flow) t-2=Exfiltration (Exfiltration Controls 0.10 cfs) -4=Culvert (Passes 7.78 cfs of 8.47 cfs potential flow) t-1=Orifice/Grate (Orifice Controls 7.78 cfs @ 4.40 fps) 21361 PROPOSED MSE 24-hr 3 100y 24hrAT-14 Rainfall=7.81" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD® 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 40 Pond 3P: UNDERGROUND FILTRATION BASIN - Chamber Wizard Field A Chamber Model= Prinsco Dual-Wall 60"(Prinsco GoldFlo®,GoldFlo WTO, EcoFlo®100, GoldPro Storm pipe) Inside= 59.7"W x 59.7"H => 19.44 sf x 20.00'L= 388.8 cf Outside= 66.7"W x 66.7"H => 22.75 sf x 20.00'L= 455.0 cf Row Length Adjustment= +15.00'x 19.44 sf x 4 rows 66.7" Wide + 30.0" Spacing = 96.7" C-C Row Spacing 3 Chambers/Row x 20.00' Long +15.00' Row Adjustment+5.56' Header x 2 = 86.12' Row Length +12.0" End Stone x 2 = 88.12' Base Length 4 Rows x 66.7" Wide + 30.0" Spacing x 3 + 12.0" Side Stone x 2 = 31.73' Base Width 66.7" Chamber Height+ 6.0" Stone Cover= 6.06' Field Height 12 Chambers x 388.8 cf +15.00' Row Adjustment x 19.44 sf x 4 Rows+ 29.73' Header x 19.44 sf x 2 = 6,987.7 cf Chamber Storage 12 Chambers x 455.0 cf +15.00' Row Adjustment x 22.75 sf x 4 Rows + 29.73' Header x 22.75 sf x 2 = 8,178.2 cf Displacement 16,940.5 cf Field - 8,178.2 cf Chambers = 8,762.4 cf Stone x 40.0%Voids = 3,504.9 cf Stone Storage Chamber Storage + Stone Storage = 10,492.7 cf= 0.241 of Overall Storage Efficiency = 61.9% Overall System Size = 88.12'x 31.73'x 6.06' 12 Chambers 627.4 cy Field 324.5 cy Stone 21361 PROPOSED MSE 24-hr 3 100y 24hrAT-14 Rainfall=7.81" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD® 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 41 Pond 3P: UNDERGROUND FILTRATION BASIN Hydrograph ■Inflow (ltaecrs l 13 Primary 12= Inflow Area=1.166 ac 11- ,o- Peak EIev=933.09' Storage=9,459 cf 7.89 cis 8- U 0 lL - 5- 4- ' 3- - 2- _ /fX77/f//77/f/i/l//7/i//7/lrr////� �//�/ 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 Time (hours) 21361 PROPOSED MSE 24-hr 3 100y 24hrAT-14 Rainfall=7.81" Prepared by Civil Site Group Printed 4/5/2024 HydroCAD® 10.20-4a s/n 02202 ©2023 HydroCAD Software Solutions LLC Page 42 Stage-Area-Storage for Pond 3P: UNDERGROUND FILTRATION BASIN Elevation Surface Storage Elevation Surface Storage (feet) (sq-ft) (cubic-feet) (feet) (sq-ft) (cubic-feet) 928.00 2,796 0 933.20 2,796 9,602 928.10 2,796 99 933.30 2,796 9,698 928.20 2,796 186 933.40 2,796 9,781 928.30 2,796 268 933.50 2,796 9,873 928.40 2,796 380 933.60 2,796 9,979 928.50 2,796 514 933.70 2,796 10,090 928.60 2,796 660 933.80 2,796 10,202 928.70 2,796 816 933.90 2,796 10,314 928.80 2,796 980 934.00 2,796 10,426 928.90 2,796 1,151 929.00 2,796 1,328 929.10 2,796 1,509 929.20 2,796 1,695 929.30 2,796 1,886 929.40 2,796 2,080 929.50 2,796 2,277 929.60 2,796 2,477 929.70 2,796 2,680 929.80 2,796 2,885 929.90 2,796 3,092 930.00 2,796 3,301 930.10 2,796 3,511 930.20 2,796 3,723 930.30 2,796 3,936 930.40 2,796 4,150 930.50 2,796 4,364 930.60 2,796 4,580 930.70 2,796 4,795 930.80 2,796 5,011 930.90 2,796 5,227 931.00 2,796 5,442 931.10 2,796 5,657 931.20 2,796 5,871 931.30 2,796 6,085 931.40 2,796 6,298 931.50 2,796 6,509 931.60 2,796 6,719 931.70 2,796 6,927 931.80 2,796 7,133 931.90 2,796 7,337 932.00 2,796 7,539 932.10 2,796 7,738 932.20 2,796 7,934 932.30 2,796 8,126 932.40 2,796 8,315 932.50 2,796 8,499 932.60 2,796 8,679 932.70 2,796 8,853 932.80 2,796 9,021 932.90 2,796 9,182 933.00 2,796 9,334 933.10 2,796 9,476 OAK PARK HEIGHTS APARTMENTS Civil Site Group-Stormwater Calculations Existing Conditions Drainage Area Impervious Area Pervious Area Total Area Area[SF] CN Value Area[SF] CN Value _ Area[SF] CN Value EX1 0 98 264143 61 264143 61 Proposed Conditions Drainage Area Impervious Area Pervious Area Total Area Area[SF] CN Value Area[SF] CN Value Area[SF] CN Value PR1 424 98 113284 61 113708 61 PR2 49764 98 49896 61 99660 79 PR3 34089 98 16686 61 50775 86 Site Area Summary Impervious[SF] Impervious[AC] Pervious[SF] Pervious[AC] Total[SF] Total[AC] Existing Site 0 0.00 264143 6.06 264143 6.06 Proposed Site 84277 1.93 179866 4.13 264143 6.06 Stormwater Rate Summary Drainage Area Existing Rate(cfs) 2-YR[2.94"] 10-YR[4.47"] 100-YR[7.81"] EX1 2.61 11.31 37.37 TOTAL 2.61 11.31 37.37 Drainage Area Prosed Conditions Rate(cfs) 2-YR[2.94"] 10-YR[4.471 100-YR[7.811 PR1 1.16 4.92 16.14 PR2(2P) 4.88 9.05 19.49 PR3(3P) 0.10 0.66 7.89 TOTAL 6.13 13.99 42.30 Overall Stormwater Rate Summary Existing Conditions Proposed Conditions Rate(cfs) Rate(cfs) 2-Year Event 2.61 6.13 10-Year Event 11.31 13.99 100-Year Event 37.37 42.30 Stormwater Water Quality and Volume Summary Drainage Area Required Infiltration Vol.Summary Filtration Volume= New Impv.Area(sf) Required Volume(cf) 1.1"`Dist.Impv.Area PR1 424 39 PR2A 49764 4562 PR2B 34089 3125 TOTAL 84277 7725 Proposed BMP Area Provided Vol(cf) Drawdown Time Calculations(0.8"/Hour) Inf.Area(sf) Assoc.Inf.Height(ft) Drawdown Time(h) Aboveground Filtration Basir 3897 1955 1.99 14.95 Underground Filtration Basir 6509 2796 2.33 17.46 TOTAL 10406 HAU G O October 11,2021 HGTS Project Number:21-0927 Mr.Jeremy Larson Suite Living/Hampton Companies,LLC 1341 County Road D Circle Vadnais Heights,MN 55109 Re: Geotechnical Exploration Report, Proposed Oak Park Heights Apartments, 58XX 58th Street N,Oak Park Heights,Minnesota Dear Mr.Larson: We have completed the geotechnical exploration report for the proposed apartment complex in Oak Park Heights, Minnesota. A brief summary of our results and recommendations is presented below. Specific details regarding our procedures, results and recommendations follow in the attached geotechnical exploration report. Six(6)soil borings were completed for this project that generally encountered varying depths of topsoil and/or Possible Fill underlain by a variety of sandy, silty and clayey soils that extended to the termination depth of the borings. Groundwater was not encountered in the soil borings while drilling and sampling or after removal of the auger from the boreholes. The vegetation and topsoil are not suitable for foundation support and will need to be removed and replaced as needed with suitable compacted engineered fill. Portions of the underlying clayey soils had a soft consistency and some soil corrections to remove any soft clays will be required. With the building pad prepared as recommended it is our opinion that the footings can be designed for a net allowable soil bearing capacity up to 3,000 pounds per square foot(psi). Thank you for the opportunity to assist you on this project. If you have any questions or need additional information,please contact Paul Gionfriddo at 612-271-8185. Sincerely, Haugo GeoTechnical Services ,(2.4t— /71-AC 62,-e*6°72-friZ` Jesse Miller,E.I.T. Paul Gionfriddo Staff Engineer Senior Engineer 1 GEOTECHNICAL EXPLORATION REPORT PROJECT: Proposed Suite Living Apartment Complex 58XX 58th Street North Oak Park Heights,MN 55082 PREPARED FOR: Suite Living/Hampton Companies,LLC 1341 County Road D Circle Vadnais Heights,MN 55109 PREPARED BY: Haugo GeoTechnical Services 2825 Cedar Avenue South Minneapolis,MN 55407 Haugo GeoTechnical Services Project:21-0927 October 11,2021 I hereby certify that this plan,specification,or report was prepared by me or under my direct supervision and that I am a duly Registered Professional Engineer under the laws of the State of Minnesota. Paul Gionfriddo,P.E. .4s1) : a Senior Engineer psocEss'-Rt• : License Number:23093 '�.�; IVY;e' • GF it*�§4� 2 Table of Contents 1.0 INTRODUCI ION 4 1.1 Project Description 4 1.2 Purpose 4 1.3 Site Description 4 1.4 Scope of Services 4 1.5 Documents Provided 5 1.6 Locations and Elevations 5 2.0 FIELD PROCEDURES 5 3.0 RESULTS 6 3.1 Soil Conditions 6 3.2 Groundwater 6 3.3 Laboratory Testing 7 3.4 OSHA Soil Classification 7 4.0 DISCUSSION AND RECOMMENDATIONS 7 4.1 Proposed Construction 7 4.2 Discussion 8 4.3 Site Grading Recommendations 9 4.4 Dewatering 10 4.5 Interior Slabs 10 4.6 Below Grade Walls 10 4.7 Exterior Slabs 11 4.8 Site Grading and Drainage 12 4.9 Utilities 12 4.10 Pavements 12 4.11 Materials and Compaction 13 4.12 Infiltration Areas-Stormwater Ponds 14 5.0 CONSTRUCTION CONSIDERATIONS 14 5.1 Excavation 14 5.2 Observations 14 5.3 Backfill and Fills 14 5.4 Testing 14 5.5 Winter Construction 15 6.0 PROCEDURES 15 6.1 Soil Classification 15 6.2 Groundwater Observations 15 7.0 GENERAL 15 7.1 Subsurface Variations 15 7.2 Review of Design 16 7.3 Groundwater Fluctuations 16 7.4 Use of Report 16 7.5 Level of Care 16 APPENDIX Boring Location Sketch,Figure 1 GPS Coordinates,Figure 2 Soil Boring Logs,SB-1 thru SB-6 Descriptive Terminology 3 1.0 INTRODUCTION 1.1 Project Description Suite Living/Hampton Companies,LLC is proposing to construct an apartment complex on a vacant parcel of land on the north side of 58th Street N between the addresses of 5900 and 5825 58th Street N in Oak Park Heights,Minnesota. Suite Living/Hampton Companies,LLC retained Haugo GeoTechnical Services (HGTS) to perform a geotechnical exploration to evaluate the suitability of site soil conditions to support the proposed development. 1.2 Purpose The purpose of this geotechnical exploration was to characterize subsurface soil and groundwater conditions and provide recommendations for foundation and pavement design and construction. 1.3 Site Description The project site is generally located on the southern portion an approximate 71/4 acre parcel that is located on the north side of 58th Street N between the addresses of 5900 and 5825 58th Street N in Oak Park Heights, Minnesota. The project site was vacant at the time of our exploration and was mostly covered with tall grasses and weeds with several smaller pine trees throughout the site. Topography of the site was relatively flat and level but sloped downhill to the northeast toward a pond on the approximate north half of the overall parcel. Ground surface elevations at the soil boring locations ranged from about 941 to 9331 feet above mean sea level(MSL). 1.4 Scope of Services Our services were performed in accordance with our cost estimate dated August 23,2021 and as authorized by Suite Living/Hampton Companies, LLC. Our services were performed under the terms of our General Conditions and were limited to the following tasks: • Completing six(6)standard penetration test soil borings with 4 boring extending to nominal depths of 30 feet and 2 borings extending to nominal depths of 10 feet. • Sealing the borings in accordance with Minnesota Department of Health requirements. • Obtaining GPS coordinates and ground surface elevations at the soil boring locations. • Visually/manually classifying samples recovered from the soil borings. • Performing laboratory tests on selected samples. • Preparing soil boring logs describing the materials encountered and the results of groundwater level measurements. • Preparing an engineering report describing soil and groundwater conditions and providing recommendations for foundation design and construction. 4 1.5 Documents Provided We were provided a"Building Location Study" dated August 11,2021 that was prepared by Civil Site Group.The Building Location Study showed 2 options for the location/layout of the P facilitysuperimposed onto an aerial photograph of the property. One of the options was crossed out. The remaining option showed an"L" shaped facility with a surface parking lot on the west/southwest side of the building. Other than the Building Location Study, specific architectural, structural or civil plans were not provided. 1.6 Locations and Elevations The soil boring locations were selected by Suite Living/Hampton Companies, LLC and/or Civil site Group. The approximate locations of the soil borings are shown on Figure 1,"Soil Boring Location Sketch," in the Appendix.The sketch was prepared by HGTS using an aerial image from Google Earth as a base. HGTS obtained the ground surface elevation at the boring location using GPS technology based on the MN County Coordinate System (Washington County) in US Survey Feet. GPS Coordinates at the boring locations are provided on Figure 2 in the Appendix. 2.0 FIELD PROCEDURES The standard penetration test borings were advanced on September 7th and 8th,2021 by HGTS with a rotary drilling rig, using continuous flight augers to advance the boreholes. Representative samples were obtained from the borings, using the split-barrel sampling procedures in general accordance with ASTM Specification D-1586. In the split-barrel sampling procedure, a 2-inch O.D. split-barrel spoon is driven into the ground with a 140- pound hammer falling 30 inches.The number of blows required to drive the sampling spoon the last 12 inches of an 18-inch penetration is recorded as the standard penetration resistance value, or "N" value. The results of the standard penetration tests are indicated on the boring log. The samples were sealed in containers and provided to HGTS for testing and soil classification. A field log of each boring was prepared by HGTS.The logs contain visual classifications of the soil materials encountered during drilling, as well as the driller's interpretation of the subsurface conditions between samples and water observation notes. The final boring logs included with this report represent an interpretation of the field logs and include modifications based on visual/manual method observation of the samples. The soil boring logs, general terminology for soil description and identification, and classification of soils for engineering purposes are also included in the appendix. The soil boring logs identify and describe the materials encountered,the relative density or consistency based on the Standard Penetration resistance (N-value, "blows per foot") and groundwater observations. 5 The strata changes were inferred from the changes in the samples and auger cuttings. The depths shown as changes between strata are only approximate. The changes are likely transitions,variations can occur beyond the location of the boring. 3.0 RESULTS 3.1 Soil Conditions At the surface the soil borings encountered about l to 1 foot of topsoil that was composed of sandy lean clay, or silty clayey sand that was brown, dark brown or black in color and contained some roots. Below the topsoil soil borings SB-2 and SB-4 encountered Possible Fill soil that extended to depths ranging from 7 to 9 i/z feet below the ground surface. Soils were composed of poorly graded sand,silty sand or clayey sand that contained some roots at depth and because of that the soils were identified as Possible Fill. Penetration resistance values (N-Values), shown as blows per foot (bpf) on the boring logs, within the sandy alluvial soils (poorly graded sand with silt, silty sand, and clayey sand) ranged from 11 to 27 bpf. These values indicate the sandy Fill soils had a medium dense relative density. Below the topsoil and Possible Fill, the soil borings encountered native alluvial soils that extended to the termination depths of the borings. The alluvial soils consisted of poorly graded sand, poorly graded sand with silt, silty sand, sandy silt, lean clay, and sandy lean clay. These soils generally correspond to the ASTM Classifications SP,SP-SM,SM, ML, and CL,respectively. N-Values within the sandy and silty alluvial soils ranged from 7 to 54 bpf indicating a loose to very dense relative density, however most of the values ranged from about 7 to 30 bpf, indicating a loose to medium dense relative density. The higher N-Values,generally greater than 30 bpf were likely due to gravel and cobbles. 3.2 Groundwater Groundwater was not encountered in the soil borings while drilling and sampling or after removal of the auger from the boreholes. Groundwater appears to be below the depths explored by our borings. Water levels were measured on the dates as noted on the boring logs and the period of water level observations was relatively short. Groundwater monitoring wells or piezometers would be required to more accurately determine water levels. Seasonal and annual fluctuations in the groundwater levels should be expected. 6 3.3 Laboratory Testing Laboratory moisture content tests were performed on selected samples recovered from the soil borings. Table 1 summarizes the results of the laboratory tests. Results of the moisture content tests are also shown on the boring logs adjacent to the sample tested. Table 1.Summary of Laboratory Tests Boring Sample Depth Moisture Number Number (feet) Content(%) * SB-2 SS-11 121 281/2 SB-4 SS-24 7/ 17 SB-5 SS-34 71 121 SB-5 SS-36 121/z 291 SB-6 SS-43 5 151/2 SB-6 SS-45 10 21 *Moisture content values rounded to the nearest 1/2 percent. 3.4 OSHA Soil Classification The soils encountered in the borings consisted of a variety of soil types including; poorly graded sand,poorly graded sand with silt,silty sand,clayey sand,silty clayey sand,lean clay, sandy lean clay and sandy silt,corresponding to the ASTM Classifications of SP,SP-SM,SM, SC,SC-SM, CL and ML, respectively. The sandy soils will generally be Type C soils under Department of Labor Occupational Safety and Health Administration (OSHA) guidelines. The clayey soils generally had a soft consistency and for that reason they will also generally be Type C soils under OSHA guidelines. An OSHA-approved qualified person should review the soil classification in the field. Excavations must comply with the requirements of OSHA 29 CFR, Part 1926, Subpart P, "Excavations and Trenches." This document states excavation safety is the responsibility of the contractor.The project specifications should reference these OSHA requirements. 4.0 DISCUSSION AND RECOMMENDATIONS 4.1 Proposed Construction We understand the proposed apartment building will include 3 levels of living spaces above a below ground parking level along with the associated surface parking areas drive lanes and underground utilities. We were not provided specific structural drawings or design information structure. For the purpose of this evaluation, we assume the below grade construction will consist of cast in- place concrete or masonry block foundation walls supported on concrete spread footings. Cast in-place concrete or precast concrete columns will likely support precast concrete floor plans over the garage level. Above grade construction is anticipated to consist of wood framing,a pitched roof and asphalt shingles. 7 Based on the assumed construction we estimate perimeter footing loads on the order of 5 to 6 kips (5,000 to 6,000 pounds) per lineal foot and interior column loads will be on the order of 300 kips(300,000 pounds). We further anticipate that soil bearing pressure(s)of 3,000 pounds per square foot(psf)will be required for foundation support. We understand that building grades have not yet been determined. For this evaluation we've assume that the main floor will bear at or slightly above existing site grades corresponding to about elevation 938 feet with the garage slab about 10 feet below that corresponding to about elevation 928 feet MSL. We have attempted to describe our understanding of the project. If the proposed loads exceed these values or if the design or location of the proposed building changes, we should be informed. Additional analyses and revised recommendations may be necessary. 4.2 Discussion The vegetation and topsoil encountered in the borings are compressible and are not suitable for building,pavement or utility support and will need to be removed from below these areas and oversize areas and replaced,as needed,with suitable compacted engineered fill. The soil borings encountered soft clayey soil at the anticipated foundation levels which are not suitable for foundation support. The soft clays will need to be removed and replaced with suitable compacted engineered fill to provided adequate foundation support. Soft clayey soils extended to about 15 feet at soil boring SB-2 and to depths ranging from about 15 to 20 feet below the ground surface near soil boring B-5. It might be possible to reuse the clayey soils excavated during soil corrections provided they are free of debris or other unsuitable material. Laboratory moisture content of the clayey sols ranged from about 17 to 28 l percent indicating they were likely above their assumed optimum soil moisture content based in the standard Proctor. Clayey soils that will be reused will require some moisture conditioning(drying)to meet the recommend compaction levels. Summer months are typically more favorable for drying wet soils. The underlying sandy alluvial soils in our opinion are suitable for foundation support. Lose sands,if any,and any soils disturbed during excavation and grading activities will need to be compacted prior to placing additional fill or foundations. Groundwater was not encountered in the borings while drilling and sampling or after removal of the auger from the boreholes.We do not anticipate that groundwater will be encountered during construction and do not anticipate that dewatering will be required. With the building pad prepared as recommended, it is our opinion the footings can be designed for a net allowable bearing pressure up to 3,000 pounds per square foot(psf). 8 4.3 Site Grading Recommendations Excavation We recommend that all vegetation, topsoil and any soft or otherwise unsuitable materials be removed from below the proposed building and oversize areas. Table 2 below summarizes the anticipated excavation depths at the soil boring locations. Excavation depths may vary and could be deeper. Table 2.Anticipate d Excavation Depths Measured Anticipated Anticipated Approximate Boring Surface Excavation Excavation Groundwater Number Elevation Depth(feet)* Elevation(feet)* Elevation* (feet) SB-1 938.4 2 1/2(Parking) 936 NE SB-2 936.2 141 921 1/2 NE SB-3 936.7 1 (Parking) 936 NE SB-4 936.3 91h 927 NE SB-5 933.6 15-20 9181 -9131 NE SB-6 941.0 121h 9281 NE *=Excavation and groundwater elevations were rounded to nearest 1/2 foot. NE=Not Encountered Oversizing In areas where the excavations extend below the proposed footing elevations,the excavations require oversizing.We recommend the perimeter of the excavation be extended a foot outside the proposed footprint for every foot below footing grade(1H:1V oversizing).The purpose of the oversizing is to provide lateral support of the foundation. Fill Material Fill required to attain site grades may consist of any debris-free, non-organic mineral soil,provided it is free of debris,organic materials or other unsuitable material. We recommend granular material meeting the ASTM Classification of SP or SP-SM soils for ease in compaction and to provide a uniform subgrade. The on-site native alluvial soils appear generally suitable for reuse as structural fill,provided they are free of organic matter or other deleterious material. However, portions of the soils could require some moisture conditioning(wetting or drying)to achieve proper compaction. The topsoil or soils that are black in color are not suitable for reuse as structural fill or backfill. Backfilling We recommend that any loose sands or soil disturbed during excavation activities be surface compacted to increase their density and uniformity prior to placing additional fill and/or footings. We recommend the exposed soil be surface compacted with a large self- propelled vibratory compactor operating in vibratory mode. We recommend that backfill placed to attain site grades be compacted to a minimum of 95 percent of its standard Proctor density(ASTM D 698). Granular fill classified as SP or SP-SM should be placed within 65 percent to 105 percent of its optimum moisture content as determined by the standard Proctor. Other fill soils should be placed within 3 percentage points above and 1 percentage point below its optimum moisture content as determined by 9 the standard Proctor.All fill should be placed in thin lifts and be compacted with a large self- propelled vibratory compactor operating in vibratory mode. Foundations We recommend the perimeter footings bear a minimum of 42 inches below the exterior grade for frost protection. Interior footings may be placed immediately below the slab provided construction does not occur during below freezing weather conditions. Foundation elements in unheated areas(i.e.,deck or porch footings)should bear at least 5 feet below exterior grade for frost protection. We anticipate the foundations and floor slabs will bear on compacted engineered fill over native alluvial soils. With the building pad prepared as recommended, it is our opinion the footings can be designed for a net allowable bearing pressure up to 3,000 pounds per square foot(psf). We anticipate total and differential settlement of the foundations will be less than 1 inch and l inch,respectively,across a 30-foot span. 4.4 Dewatering Groundwater was not encountered in the soil borings while drilling and sampling or after removal of the auger from the boreholes. We do not anticipate that groundwater will be encountered during construction and do not anticipate that dewatering will be required. 4.5 Interior Slabs The anticipated floor subgrade will consist of compacted sandy engineered fill or sandy alluvial soils. It is our opinion a modulus of subgrade reaction,k, of 100 pounds per square inch per inch of deflection may be used to design the floor. If floor coverings or coatings less permeable than the concrete slab will be used, we recommend that a vapor retarder or vapor barrier be placed immediately beneath the slab. Some contractors prefer to bury the vapor barrier or vapor retarder beneath a layer of sand to reduce curling and shrinkage,but this practice often traps water between the slab and vapor retarder or barrier. Regardless of where the vapor retarder or vapor barrier is placed, we recommend consulting the floor covering manufacturer regarding the appropriate type,use and installation of the vapor retarder or vapor barrier to preserve the warranty. We recommend following all state and local building codes with regards to a radon mitigation plan beneath interior slabs. 4.6 Below Grade Walls We recommend general waterproofing of the below grade walls. We recommend either placing drainage composite against the backs of the exterior walls or backfilling adjacent to the walls with sand having less than 50 percent of the particles by weight passing the#40 sieve and less than 5 percent of the particles by weight passing the #200 sieve. The sand backfill should be placed within 2 feet horizontally of the wall. We recommend the balance of the backfill for the walls consist of sand however the sand may contain up to 20 percent of the particles by weight passing the#200 sieve. 10 We recommend installing drain tile behind the below grade walls,adjacent to the wall footing and below the slab elevation. Preferably the drain tile should consist of perforated pipe embedded in gravel. A geotextile filter fabric should encase the pipe and gravel. The drain tile should be routed to a storm sewer,sump pump or other suitable disposal site. Foundation walls or below grade (basement) walls will have lateral loads from the surrounding soil transmitted to them. Active earth pressures can be used to design the below grade walls if the walls are allowed to rotate slightly. If wall rotation cannot be tolerated,then below grade wall design should be based on at-rest earth pressures. It is our opinion that the estimated soil parameters presented in Table 3 can be used for below grade wall design. These estimated soil parameters are based on the assumptions that the walls are drained,there are no surcharge loads within a horizontal distance equal to the height of the wall and the backfill is level. Table 3. Soil Parameters Estimated Estimated Active Unit Friction At-Rest Soil Passive Soil Soil Type Pressure Pressure Weight Angle Pressure (pcf) (degrees) (pcf) (pcf) (pcf) Sands 120 32 55 35 390 (SP&SP-SM) Clayey and Silty Soils 135 28 70 50 375 (CL,ML,SC&SM) Resistance to lateral earth pressures will be provided by passive resistance against the wall footings and by sliding resistance along the bottom of the wall footings. We recommend a sliding coefficient of 0.35.This value does not include a factor of safety. 4.7 Exterior Slabs Exterior slabs will likely be underlain by silty or clayey soils which are considered moderately to highly frost susceptible. If these soils become saturated and freeze,frost heave may occur. This heave can be a nuisance in front of doors and at other critical grade areas. One way to help reduce the potential for heaving is to remove the frost-susceptible soils below the slabs down to bottom of footing grades and replace them with non-frost-susceptible backfill consisting of sand having less than 5 percent of the particles by weight passing the number 200 sieve. If this approach is used and the excavation bottoms terminate in non-free draining granular soil,we recommend a drain tile be installed along the bottom outer edges of the excavation to collect and remove any water that may accumulate within the sand. The bottom of the excavation should be graded away from the building. If the banks of the excavations to remove the frost-susceptible soils are not sloped, abrupt transitions between the frost-susceptible and non-frost-susceptible backfill will exist along which unfavorable amounts of differential heaving may occur. Such transitions could exist between exterior slabs and sidewalks, between exterior slabs and pavements and along the slabs themselves if the excavations are confined to only the building entrances. To address 11 this issue, we recommend sloping the excavations to remove frost-susceptible soils at a minimum 3:1 (horizontal:vertical)gradient. Another alternative for reducing frost heave is to support the slabs on frost depth footings. A void space of at least 4 inches should be provided between the slab and the underlying soil to allow the soil to heave without affecting the slabs. 4.8 Site Grading and Drainage We recommend the site be graded to provide positive run-off away from the proposed building. We recommend landscaped areas be sloped a minimum of 6 inches within 10 feet of the building and slabs be sloped a minimum of 2 inches. In addition, we recommend downspouts with long splash blocks or extensions. We recommend the lowest floor grades be constructed to meet City of Oak Park Heights requirements with respect to groundwater separation distances. In the absence of city requirements,we recommend maintaining at least a 4-foot separation between the lowest floor slab and the observed groundwater levels and at least a 2-foot separation between the lowest floor slab and the 100-year flood level of nearby wetlands,storm water ponds or other surface water features. 4.9 Utilities We anticipate that new utilities could be installed as part of this project.We further anticipate that new utilities will bear at depths ranging from about 7 to 10 feet below the ground surface. At these depths, we anticipate that the pipes will bear on native alluvial soils which in our opinion are generally suitable for pipe support. We recommend removing all vegetation, topsoil and any soft or otherwise unsuitable materials, if any, beneath utilities prior to placement. We recommend bedding material be thoroughly compacted around the pipes. We recommend trench backfill above the pipes be compacted to a minimum of 95 percent beneath slabs and pavements, the exception being within 3 feet of the proposed pavement subgrade, where 100 percent of standard Proctor density is required.In landscaped areas,we recommend a minimum compaction of 90 percent. Groundwater was not encountered in the soil borings and we do not anticipate that groundwater will be encountered during utility construction. 4.10 Pavements General The city of Oak Park Heights may have standard plates that dictate pavement design. If so, we recommend that pavements be designed and constructed in accordance with the appropriate standard plates. The following paragraphs provide general pavement recommendations in the absence of City of Oak Park Heights standard plates. Based on the site Building location Study it appears that the surface the parking lot will include approximately 75 stalls. We anticipate that the parking areas will be used predominately by automobiles and light trucks with weekly use by heavier vehicles such as garbage trucks. Based on the assumed traffic types we anticipate that both light duty and heavy-duty 12 pavements will be required. Based on the assumed traffic types we estimate the pavements will be subjected to a maximum of 50,000 Equivalent Single Axel Loads(ESAL's)over a design life of 20 years. Subgrade Preparation We recommend removing all vegetation and topsoil and any soft or otherwise unsuitable materials from beneath the pavement subgrade. Prior to placing the aggregate base(Class 5)we recommend compacting the subgrade and/or performing a proof- roll to identify soft,weak,loose,or unstable areas that may require additional subcuts. Backfill, if needed, to attain pavement subgrade elevation can consist of any mineral soil provided it is free of organic material or other deleterious materials. Granular fill classified as SP or SP-SM should be placed within 65 percent to 105 percent of its optimum moisture content as determined by the standard Proctor. Other fill soils should be placed with moisture contents within a range of 1 percentage point below and 3 percentage points above its optimum moisture content. The upper 3 feet of fill and backfill should be compacted to a minimum of 100 percent of its standard Proctor maximum dry density. Subgrade R-Value R-Value testing was beyond the scope of this project. Below the topsoil the soil borings predominantly encountered silty sand soils. R-Values in these soils can range from 20 to 50 or more. It is our opinion that an R-Value of 30 can be used for pavement design. Bituminous Pavements It should be noted that the pavement sections presented below are not absolutes. Depending on serviceability expectations,material availability,and cost,there could be circumstances under which alternative sections could be more practicable. For silty sand subgrade soils,an estimated R-value of 30 and a maximum of 50,000 ESAL's we recommend a light duty pavement section consisting of a minimum of 3 1/2 inches of bituminous(11/2 inches of wear course and 2 inches of base course)underlain by a minimum of 8 inches of aggregate base. If heavy duty section is required,we recommend a pavement section consisting of a minimum of 4 inches of bituminous(2 inches of wear course and 2 inches of base course)underlain by a minimum of 9 inches of aggregate base. 4.11 Materials and Compaction We recommend specifying aggregate base meeting MN/DOT Class 5 aggregate base. We recommend the aggregate base be compacted to 100 percent of its maximum standard Proctor. We recommend that the bituminous wear and base courses meet the requirement of Mn/DOT Specification 2360 for bituminous mixes. We recommend the bituminous pavements be compacted to at least 92% of the maximum theoretical density. We recommend specifying concrete that has a minimum 28-day compressive strength of 4,000 psi,and a modulus of rupture of at least 600 psi. We recommend Type I cement meeting the requirements of ASTM C150. We recommend specifying 5 to 7 percent entrained air for exposed concrete to provide resistance to freeze-thaw deterioration. We also recommend using a water/cement ratio of 0.45 or less for concrete exposed to deicers. 13 4.12 Infiltration Areas - Stormwater Ponds We anticipate that storm water/infiltration pond(s)could be constructed as part of this project. However, no information regarding their locations on the property or the bottom of pond elevations were provided. The soil borings encountered a variety of soil types which can have a wide range of infiltration rates. Once the location(s)and depths of any ponds has been determined we can provide estimated soil infiltration rates for use in pond design. Alternately, field tests(double ring infiltrometer) could be performed within the proposed basin areas to determine infiltration rates of the in- situ soils. We would be pleased to provide these services if required or requested. 5.0 CONSTRUCTION CONSIDERATIONS 5.1 Excavation The soils encountered in the borings consisted of a variety of soil types including; poorly graded sand,poorly graded sand with silt,silty sand,clayey sand,silty clayey sand,lean clay, sandy lean clay and sandy silt,corresponding to the ASTM Classifications of SP,SP-SM,SM, SC, SC-SM, CL and ML, respectively. The sandy soils will generally be Type C soils under Department of Labor Occupational Safety and Health Administration (OSHA) guidelines. The clayey soils generally had a soft consistency and for that reason they will also generally be Type C soils under OSHA guidelines. Temporary excavations in Type C soils should be constructed at a minimum of 11 foot horizontal to every 1 foot vertical within excavations. Slopes constructed in this manner may still exhibit surface sloughing. If site constraints do not allow the construction of slopes with these dimensions,then temporary shoring may be required. 5.2 Observations A geotechnical engineer or qualified engineering technician should observe the excavation subgrade to evaluate if the subgrade soils are similar to those encountered in the borings and adequate to support the proposed construction. 5.3 Backfill and Fills We recommend moisture conditioning(drying or wetting) all soils that will be used as fill or backfill in accordance with Section 4.3 above. We recommend that fill and backfill be placed in lifts not exceeding 4 to 12 inches, depending on the size of the compactor and materials used. 5.4 Testing We recommend density tests of backfill and fills placed for the proposed foundations.Samples of the proposed materials should be submitted to our laboratory prior to placement for evaluation of their suitability and to determine their optimum moisture content and maximum dry density(Standard Proctor). 14 5.5 Winter Construction If site grading and construction is anticipated to proceed during cold weather, all snow and ice should be removed from cut and fill areas prior to additional grading and placement of fill. No fill should be placed on frozen soil and no frozen soil should be used as fill or backfill. Concrete delivered to the site should meet the temperature requirements of ASTM and/or ACI. Concrete should not be placed on frozen soil.Concrete should be protected from freezing until the necessary strength is obtained. Frost should not be permitted to penetrate below the footings. 6.0 PROCEDURES 6.1 Soil Classification The drill crew chief visually and manually classified the soils encountered in the borings in general accordance with ASTM D 2488, "Description and Identification of Soils (Visual- Manual Procedure)."Soil terminology notes are included in the Appendix.The samples were returned to our laboratory for review of the field classification by a soils engineer. Samples will be retained for a period of 30 days. 6.2 Groundwater Observations Immediately after taking the final samples in the bottom of the boring,the hole was checked for the presence of groundwater. Immediately after removing the augers from the borehole the hole was once again checked and the depth to water and cave-in depths were noted. 7.0 GENERAL 7.1 Subsurface Variations The analyses and recommendations presented in this report are based on data obtained from a limited number of soil borings. Variations can occur away from the borings,the nature of which may not become apparent until additional exploration work is completed, or construction is conducted. A reevaluation of the recommendations in this report should be made after performing on-site observations during construction to note the characteristics of any variations. The variations may result in additional foundation costs and it is suggested that a contingency be provided for this purpose. It is recommended that we be retained to perform the observation and testing program during construction to evaluate whether the design is as expected,if any design changes have affected the validity of our recommendations, and if our recommendations have been correctly interpreted and implemented in the designs, specifications and construction methods. This will allow correlation of the soil conditions encountered during construction to the soil borings and will provide continuity of professional responsibility. 15 7.2 Review of Design This report is based on the design of the proposed structures as related to us for preparation of this report.It is recommended that we be retained to review the geotechnical aspects of the design and specifications. With the review, we will evaluate whether any changes have affected the validity of the recommendations and whether our recommendations have been correctly interpreted and implemented in the design and specifications. 7.3 Groundwater Fluctuations We made water level measurements in the borings at the times and under the conditions stated on the boring logs. The data was interpreted in the text of this report. The period of observation was relatively short and fluctuations in the groundwater level may occur due to rainfall,flooding,irrigation,spring thaw,drainage,and other seasonal and annual factors not evident at the time the observations were made. Design drawings and specifications and construction planning should recognize the possibility of fluctuations. 7.4 Use of Report This report is for the exclusive use of Suite Living/Hampton Companies,LLC and their design team to use to design the proposed structures and prepare construction documents. In the absence of our written approval,we make no representation and assume no responsibility to other parties regarding this report. The data, analysis and recommendations may not be appropriate for other structures or purposes.We recommend that parties contemplating other structures or purposes contact us. 7.5 Level of Care Haugo GeoTechnical Services has used the degree of skill and care ordinarily exercised under similar circumstance by members of the profession currently practicing in this locality. No warranty expressed or implied is made. 16 APPENDIX -,:-.47-7' _.,,_ ' � '�' .mss,. :z Y= : yr SB-6 SB 5 - • g SB-4 � a _ a.. 's a '^ —,, „' -, ' -ANs SB 3 r 1 Z SB-2 G k lki- r ,a"` ff . * SB-1 ger. N Legend Approximate Soil Boring Location w ,,' : `E a ee Disclaimer:Map and parcel data are believed to be accurate,but accuracy is not guaranteed.This is not a legal document and should not be substi[uned for a title search,appraisal,survey,or for zoning verifcation. Figure#: 1 Haugo GeoTechnical Soil Boring Location Sketch Drawn By:EC Services,LLC Suite Living Oak Park Heights Date:9/10/2021 2825 Cedar Avenue S. Scale:9N/100n/ None Minneapolis,MN 55407 Oak Park Heights, MN Project#:21-0927 H A lJ C3 C a ..a. . .:. HGTS# 21-0927 Figure 2: GPS Boring Locations- Apartment Site Boring Number Elevation Northing Easting (US Survey Feet) Coordinate Coordinate SB-1 938.4 204592.2 497495.1 SB-2 936.2 204679.9 497681.3 SB-3 936.7 204763.7 497575.3 SB-4 936.3 204903.4 497610.4 SB-5 933.6 204960.9 497698.7 SB-6 941.0 204962.1 497452.8 Referencing Minnesota County Coordinates Basis-Washington County 2825 Cedar Avenue S, Minneapolis, MN 55407 Haugo GeoTechnical Services BORING NUMBER SB-1 HAUGO 2825 Cedar Ave South PAGE 1 OF 1 •• Minneapolis,MN 55407 SERVICES Telephone: 612-729-2959 Fax: 763-445-2238 CLIENT Suite Living/Hampton Companies PROJECT NAME Oak Park Heights Apartments PROJECT NUMBER 21-0927 PROJECT LOCATION Oak Park Heights,MN DATE STARTED 9/8/21 COMPLETED 9/8/21 GROUND ELEVATION 938.4 ft HOLE SIZE 3 1/4 inches O DRILLING CONTRACTOR HGTS-750 GROUND WATER LEVELS: • DRILLING METHOD Hollow Stem Auger/Split Spoon AT TIME OF DRILLING —Not Encountered 1 LOGGED BY MS CHECKED BY PG AT END OF DRILLING —Not Encountered a NOTES AFTER DRILLING —Not Encountered w a z A SPT N VALUE A r rY >_ w w O 20 40 60 80 • ^ =O am wo �z� w^ w PL � LL • o- a O MATERIAL DESCRIPTION >0 O p< rr o • ov <J CLD O� mo> �` O 20 40 60 80 • C7 <z w U z o 0 FINES CONTENT(%)❑ 0 20 40 60 80 J.• ` Sandy Lean Clay,with Grass and Roots,brown to dark brown, �- -/,. 1./• moist.(Topsoil) AU 1 a 1.l•: (ML)Sandy Silt,brown,moist,medium dense.(Alluvium) ,- SS 4-7-10 - - (SP)Poorly Graded Sand,fine to medium grained,trace Gravel, 2 (17) brown,moist,medium dense(Alluvium) W 5 V SS 3-13-15 o3 (28) a ▪_ _ O - XSS 4-8-13 4 (21) 10 (ML)Sandy Silt,brown,moist,medium dense.(Alluvium) X SS 4-8-10 5 (18) Bottom of borehole at 11.0 feet. O LU c7 O ( O O m a O O LU LU N (V- 0 O o] O U N 0- 03 m w O U./ Haugo GeoTechnical Services BORING NUMBER SB-2 HAUGO 2825 Cedar Ave South PAGE 1 OF 1 •, _ Minneapolis,MN 55407 SERVICES Telephone: 612-729-2959 Fax: 763-445-2238 CLIENT Suite Living/Hampton Companies PROJECT NAME Oak Park Heights Apartments PROJECT NUMBER 21-0927 PROJECT LOCATION Oak Park Heights,MN DATE STARTED 9/7/21 COMPLETED 9/7/21 GROUND ELEVATION 936.2 ft HOLE SIZE 31/4 inches • DRILLING CONTRACTOR HGTS-750 GROUND WATER LEVELS: vi z DRILLING METHOD Hollow Stem Auger/Split Spoon AT TIME OF DRILUNG -Not Encountered w LOGGED BY MS CHECKED BY PG AT END OF DRILUNG -Not Encountered re a NOTES AFTER DRILUNG -Not Encountered in _o w 1- F: ♦SPT N VALUE A _ o 1° _ >c }_ w j 8 Cl) 20 40 60 80 cci• =-� C7- ~m re- z_J w-, w PL LL a a? -o MATERIAL DESCRIPTION ±I2 >O O D> X," • 18- §-I m p O rX m 0> P- O 20 40 60 80 p t7 <z 0 U z O Z ❑FINES CONTENT(%)0 0 0 2 20 40 60 80 ' .-.. Silty Sand,trace Roots,brown,moist.(Topsoil)in /-/ AU ������ Poorly Graded Sand with Silt,fine to medium grained,trace w ”•� Gravel,brown,moist.(Possible Fill) 6 iJJJ' cr X SS 5-6-9 7 (15) m- �ii�i� 5 .• I- �0 w � 'o v.� X SS 6-13-14 . 8 (27) - l•• ;$• , Silty Sand,trace Fibers,brown,moist.(Possible Fill) SS 4-8-8 :i�ii� X 9 (16) • iii�ii • 10 (CL)Lean Clay,trace Gravel,brown with rust staining,rather soft SS 2-2-2 2 Z / w / to soft.(Alluvium) 10 (4) ILIO CD)- \SS 1-1-1 • / 11 (2) 28.5 (SP-SM)Poorly Graded Sand with Silt,fine to medium grained, 15 brown,moist,medium dense.(Alluvium) SS 3-11-12 x X 12 (23) o CO a O- a 0 U) I _- 20 SS 6-11-11 CD 3 .. X 13 (22) \ ;:l 0 _ N- a O •• 25 (SM)Silty Sand,fine to medium grained,trace Gravel,brown, O moist,dense.(Alluvium) SS 8-16-17 3_ • X 14 (33) U I- 0- N H Z- - 30 (SP)Poorly Graded Sand,fine to medium grained,trace Gravel, SS 7-14-17 1 _ \ brown ,dense.(Alluvium) [X 15 (31) co I (SM)Silty Sand,fine to medium grained,trace Gravel,brown, / moist,dense.(Alluvium) o Bottom of borehole at 31.0 feet. 0 Haugo GeoTechnical Services BORING NUMBER SB-3 A .GO 2825 Cedar Ave South PAGE 1 OF 1 ' • Minneapolis,MN 55407 SERVICES Telephone: 612-729-2959 Fax: 763-445-2238 CLIENT Suite Living/Hampton Companies PROJECT NAME Oak Park Heights Apartments PROJECT NUMBER 21-0927 PROJECT LOCATION Oak Park Heights,MN DATE STARTED 9/7/21 COMPLETED 9/7/21 GROUND ELEVATION 936.7 ft HOLE SIZE 3 1/4 inches DRILUNG CONTRACTOR HGTS-750 GROUND WATER LEVELS: CI) DRILUNG METHOD Hollow Stem Auger/Split Spoon AT TIME OF DRILUNG —Not Encountered LOGGED BY MS CHECKED BY PG AT END OF DRILUNG —Not Encountered NOTES AFTER DRILLING —Not Encountered with Cave-In Depth of 3 Feet En ASPTNVALUEA Y = va. } cn w 20 40 60 80 a n c1-0 MATERIAL DESCRIPTION w m w 0 z< U-1-7; PL • LL W" J J� >0J�Q Q'o � o m �z O m Q>Oz F v z 20 40 60 80 Q w ❑FINES CONTENT(%)❑ 0 0 2 20 40 60 80 - - ISilty Clayey Sand,trace Roots,dark brown to black,moist. AU (Topsoil) (SP-SM)Poorly Graded Sand with Silt,fine to medium grained, 16 a trace Gravel,brown,moist,medium dense.(Alluvium) SS 6-9 7 • X 17 (16) m • 5 • (SP)Poorly Graded Sand,fine to medium grained,brown,moist, medium dense.(Alluvium) SS 4-8-10 a - X 18 (18) SS _ - Approximate 2 inch layer of Sandy Silt at about 7 1/2 Feet X 19 2(20)2 10 ✓ SS 3-8-11 2 X 20 (19) F Bottom of borehole at 11.0 feet. 0 w 0 0 U rn t- 2 X 0 0 0 0 in Co I O x Co CO w C) 0 r, O 0 w CO 0 I CO z to 0 a x m x U w I- O w Haugo GeoTechnical Services BORING NUMBER SB-4 HAU G❑ 2825 Cedar Ave South PAGE 1 OF 1 ' •• = Minneapolis,MN 55407 SERVICES Telephone: 612-729-2959 Fax: 763-445-2238 CLIENT Suite Living/Hampton Companies PROJECT NAME Oak Park Heights Apartments PROJECT NUMBER 21-0927 PROJECT LOCATION Oak Park Heights,MN DATE STARTED 9/7/21 COMPLETED 9/7/21 GROUND ELEVATION 936.3 ft HOLE SIZE 3 1/4 inches O DRILLING CONTRACTOR HGTS-750 GROUND WATER LEVELS: 0 DRILLING METHOD Hollow Stem Auger/Split Spoon AT TIME OF DRILLING —Not Encountered w LOGGED BY MS CHECKED BY PG AT END OF DRILLING —Not Encountered a NOTES AFTER DRILLING —Not Encountered w 1- r c1 w o z A SPT N VALUE• z = 0 >-o' >- c w O co 20 40 60 80 Q a w °-O MATERIAL DESCRIPTION CO > p Q o PL • LL a O v g J o O m O> Z 20 40 60 80 o O <zW z ❑FINES CONTENT(%)❑ m Cl) w 0 0 0 2 20 40 60 80 fly h :1 Silty Sand,with Grass and Roots,dark brown to black,moist. 1-• - �•����� (Topsoil) AU - • . Silty Sand,fine to medium grained,trace Gravel,brown,moist. 21 cc i •���� (Possible Fill) � SS 4-7-12 D- •*• • 22 (19) o - :�:.•: co • Clayey Sand,Trace Gravel,gray to grayish brown,moist. O 5 �,���� (Possible Fill) SS 3-5-6 �•• X 23 (11) z O (ML)Sandy Silt,brown,moist,loose.(Alluvium) SS 4-4-4 co 0 - . X 24 (8) 17 5 K- (SP)Poorly Graded Sand,fine to medium grained,trace Gravel, a 10 brown,moist,medium dense.(Alluvium) SS 3-8-9 z X 25 (17) w o SS 3-9-11 o X 26 (20) a x- - _ 15 SS 3-9-11 X X 27 (20) 0 0 o 0 w w 20 w SS 3-9-12 3 _ X 28 (21) 0 _ CO W O (SM)Silty Sand,fine to medium grained,trace Gravel, brown, I 25 moist,dense.(Alluvium) X SS 8-22-28 a 29( 50) w - 0 I-- w F- - 3 N - a 30SS 16-18-26 m . .•. X 30 (44) O Bottom of borehole at 31.0 feet. w i- 0 W 0 Haugo GeoTechnical Services BORING NUMBER SB-5 AUGO 2825 Cedar Ave South PAGE 1 OF 1 i ■ •• : Minneapolis,MN 55407 SERVICES Telephone: 612-729-2959 Fax: 763-445-2238 CLIENT Suite Living/Hampton Companies PROJECT NAME Oak Park Heights Apartments PROJECT NUMBER 21-0927 PROJECT LOCATION Oak Park Heights,MN DATE STARTED 9/7/21 COMPLETED 9/7/21 GROUND ELEVATION 933.6 ft HOLE SIZE 3 1/4 inches g DRILLING CONTRACTOR HGTS-750 GROUND WATER LEVELS: vi z DRILLING METHOD Hollow Stem Auger/Split Spoon AT TIME OF DRILLING —Not Encountered W LOGGED BY MS CHECKED BY PG AT END OF DRILLING —Not Encountered cca a NOTES AFTER DRILLING —Not Encountered U) 1- o w o z A SPT N VALUE A >-o' >- co w8 20 40 60 80 a• o_= o-O MATERIAL DESCRIPTION w >0 oz Q ,r i__ PLS MCLL a pv �J �D O . m0> 2` Z 20 40 60 80 0 FINES CONTENT(%)0 0 0 2 20 40 60 80 P.:. `' Silty Sand,trace Roots,dark brown to black,moist.(Topsoil) AU W (SM)Silty Sand,fine to medium grained,brown,moist,medium 31 a II dense.(Alluvium) cc g 4-7-10 Y "® (17) a CD 5 MEM (SP)Poorly Graded Sand,fine to medium grained,brown,moist, " q_r� a medium dense.(Alluvium) . (11) a (CL)Sandy Lean Clay,gray,wet,rather stiff.(Alluvium) _ 1- z p , oii, (ML)Sandy Silt,gray,moist,medium dense.(Alluvium) "® 2 6 7 12.5 0 . (13) J • 10 V (CL)Lean Clay, brown,wet, medium to soft.(Alluvium) 1E 3-3-4 0 i. oo (7) 0rj SS 1-1-1 0 A 36 (2) 29.5 x ; 15 0 1-1-1 o ,® (2) o o 1-- 0 w 20 .. (SP-SM)Poorly Graded Sand with Silt,fine to medium grained, 1% 3-9-13 U .. brown,moist,medium dense.(Alluvium) . (22) o co N O O 25 .. oi a '/B 2202 .. • o .. 1- Z Z 5 co o 30 • a SS 4-11-10 I Fl40 (21) 0 Bottom of borehole at 31.0 feet. W 1- 0 W 0 Haugo GeoTechnical Services BORING NUMBER SB-6 HAUGO 2825 Cedar Ave South PAGE 1 OF 1 1 Minneapolis,MN 55407 SERVICES Telephone: 612-729-2959 Fax: 763-445-2238 CLIENT Suite Living/Hampton Companies PROJECT NAME Oak Park Heights Apartments PROJECT NUMBER 21-0927 PROJECT LOCATION Oak Park Heights,MN DATE STARTED 9/7/21 COMPLETED 9/7/21 GROUND ELEVATION 941 ft HOLE SIZE 3 1/4 inches E DRILLING CONTRACTOR HGTS-750 GROUND WATER LEVELS: vi DRILLING METHOD Hollow Stem Auger/Split Spoon AT TIME OF DRILLING —Not Encountered w LOGGED BY MS CHECKED BY PG AT END OF DRILLING —Not Encountered NOTES AFTER DRILLING —Not Encountered m w z9, z ASPTNVALUE• L.Tia >-_ u>w O 20 40 60 80 a a= 0-O wm w0 �z� w^ w PL LL a w 0 MATERIAL DESCRIPTION _j 2 >a O D Q Ce o a p v CI-7 O Z m O> `- Z 20 40 60 80 o 0 2z 0 0Z ❑FINES CONTENT(%)❑ 0 0 2 20 40 60 80 +.:.a � Sandy Lean Clay,with Grass and Roots,brown to dark brown, �I AU 12- - : \ moist.(Topsoil) W (SM)Silty Sand,fine grained,brown,moist,loose.(Alluvium) 41 0- gSS 2-3-5 Y X 42 (8) a- m (ML)Sandy Silt,brown,moist,loose.(Alluvium) W 5 SS 2-2-5 15.5 a X 43 (7) a (ML)Sandy Clayey Silt,brown,wet,loose.(Alluvium) SS 3-4-4 544 (8) w- w `-' 10 X SS 45 2-22 21 0 w r . o- - oo0_ (SP)Poorly Graded Sand,fine to coarse grained,with Gravel, X 46 SS 3 30 8 a brown,moist,mediumd dense to dense.(Alluvium) ( ) x- - PI 15 X SS 4-3-29 o - 47 (32) o 0 CO I0 (SM)Silty Sand,fine to medium grained,trace Gravel,brown, wm 20 moist,very dense.(Alluvium) SS 4-6-48 m :: `: X 48 (54) 0- - to N- w o IL o 25 X SS 28-27-24 g 49 (51) w 7 U) I- I- 3 C0 _ a :.. •- SS 13-25-27 m X 50 (52) o Bottom of borehole at 31.0 feet. w 1- 0 Li, o HAU G o Descriptive Terminology of Soil S E R V I C ES 4., Standard D 2487-00 Classification of Soils for Engineering Purposes urreaxa., � (Unified Soil Classification System) Criteria for Assigning Group Symbols and Soils Classification Particle Size Identification Group Names Using Laboratory Tests a Group Boulders over 12" Symbol Group Name° Cobbles.._ 3"to 12' w c Gravels Clean Gravels Co 2 4 and 1<Co< 3 o GW Well-graded gravel' Gravel a More than 50%of 5%or less fines a Coarse 3/4'to 3' ui)B.� d coarse fraction Co<4 and/or 1 >Co>3° GP Poorly graded gravel' Fine No.4 to 3/4' a m m retained on Gravels with Fines Fines classify as ML or MN GM Silty gravel°'' Sand c g-, No.4 sieve More than 12%fines a Fines classify as CL or CH GC Clayey gravel°'y Coarse No.4 to No.10 B in N Sands Clean Sands Co 2 6 and 1 < C <3° „ Medium No.10 to No.40 SW Well-graded sand Fine . No.40 to No.200 `t a 50%or more,of 5%or less fines' C <6 and/or 1>Cc>3` SP Poorly graded sand' Silt <No.200,PI<4 or R— coarse fraction below`A"line oo passes Sands with Fines Fines classify as ML or MH SM Silty sand'9' Clay <No.200,PI24 and E No.4 sieve +More than 12%' Fines classify as CL or CH SC Clayey sand''" on or above"A"line N P1>7 and plots on or above'A'line i CL Lean clay`-' ' a£ Sifts and Clays Inorganic o a a Liquid limit PI<4 or plots below"A'liner ML Silt R' Relative Density of cn N m less than 50 Liquid limit-oven dried OL Organic clay"'m" Cohesionless Soils -o m m Organic < 0.75 C d o Liquid limit-not dried OL Organic silt i``'"` Very loose 0 to 4 BPF a,E N Silts and clays Inorganic PI plots on or above"A'line CH Fat clay"I" Loose 5 to 10 BPF o z° Liquid limit PIplots below"A'line MH i m Medium dense 11 to 30 BPF mElastic silt' c Dense 31 to 50 BPF 50 or moreLiquid limit-oven dried OrganicOH Organic clay C I m c LL m Liquid limit-not dried < 0.75 OH Organic silt''m Very dense over 50 BPF Highly Organic Soils Primarily organic matter,dark in color and organic odor PT Peat Consistency of Cohesive Soils a Based on the material passing the 3-in(75mm)sieve. Very soft 0 to 1 BPF b. If field sample contained cobbles or boulders,or both.add'with cobbles or boulders or both'to group name. Soft 2 to 3 BPF c. C.= Dwr0.0 Co=(D;.;' Rather soft_ 4to5BPF D„x DeoMedium 6 to 8 BPF Rather stiff 9 to 12 BPF d If soil contains215%sand,add'with sand'to group name _ Stiff 13 to 16 BPF e Gravels with 51012%foes require dual aynlbols: GW-GM well-graded gravel with silt Very stiff 17 to 30 BPF GW-GC well-graded gravel with Gay Hard over 30 BPF GP-GM poorly graded gravel with silt GP-GC poorly graded gravel with'ctay 1. If fines classify as CL-ML,use dual symbol GC-GM or SC-SM. . g. If fines are organic add'with organic fines`to group name. h. if soil contains 2 15%gravel.add'with graver to group name. i. Sands with 5 to 12%fines require dual symbols: ` Drilling Notes SI SM well-graded sand with silt SW-SC well-graded sand with day Standard penetration test borings were advanced by 3 1/4'or 6 1/4' SP-SM poorly graded sand with silt ID hollow-stem augers unless noted otherwise,Jetting water was used SP-SC poorly graded sand with clay to clean out auger prior to sampling only where indicated on logs. i. If Ane berg limits plot in hatched area,soil is a CL-ML_slay clay. Standard penetration test borings are designated by the prefix'Sr k If soil contains 10 to 29%plus No.200,add'with sand'or'with gravel'whichever is predominant. I. If soil contains 230%plus No.200.predominantly sand.add'sandy'to group name. (Split Tube). All samples were taken with the standard 2'OD split-tube m. If soil contains2 30%plus No.200 predominantly gravel.add-gravelly'to group name. sampler,except where noted. n. PI 2 4 and plots on or above`A'line. o. PI<4 or plots below'A'line. Power auger borings were advanced by 4'or 6'diameter continuous- p. Pt plots on or above'A`line. flight,solid-stem augers.Soil classifications and strata depths were in- q. PI plots below'A'line. ferred from disturbed samples augered to the surface and are,therefore, 60 somewhat approximate. Power auger borings are designated by the prefix"B_" 50 . ca ,- Hand auger borings were advanced manually with a 1 1/2'or 3 1/4" .--.. v`. diameter auger and were limited to the depth from which the auger could `3' ebe manually withdrawn. Hand auger borings are indicated by the prefix - 40 ' Cis-'' "P "H.' x / of N i "o , G`T BPF: Numbers indicate blows per foot recorded in standard penetration = 30 - / test.also known as"N"value. The sampler was set 6'into undisturbed r • , soil below the hollow-stem auger.Driving resistances were then counted for second and third 6'increments and added to get BPF. Where they .17 20 - ,' Off' differed significantly,they are reported in the following form: 2/12 for the re / of second and third 6'increments,respectively. a ,' & MH or OH 10i. WH:WH indicates the sampler penetrated soil under weight of hammer ' and rods alone;driving not required. 4 ��jCL-ML�j/% ML or OL WR: WR indicates the sampler penetrated soil under weight of rods 0 alone;hammer weight and driving not required, 0 10 16 20 30 40 50 60 70 80 90 100 110 TW indicates thin-walled(undisturbed)tube sample. Liquid Limit(LL) Note: All tests were run in general accordance with applicable ASTM Laboratory Tests standards. DO Dry density,pcf OC Organic content.% WD Wet density. pcf S Percent of saturation,% MC Natural moisture content, % SG Specific gravity LL Liqiuid limit,% C Cohesion,psf PL Plastic limit.% 0 Angle of internal friction PI Plasticity index, % qu Unconfined compressive strength.psf P200 %passing 200 sieve qp Pocket penetrometer strength,tsf Rev 7/07