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Home My WebLink AboutHeron Village Apartmets - Stormwater Management CalculationsStormwater Management Calculations for HERON VILLAGE APARTMENTS 2250 N. Meridian Rd Meridian, Idaho 83642 Prepared for Doug Clegg Heron Village, LLC 1342 E. Covey Run Eagle, Idaho 83616 (208) 870-5900 Prepared by Lance Warnick, P.E. Principal Engineer Aspen Engineers, Chartered Date Prepared June 26, 2013 ASPEN ENGINEERS Aspen Engineers, Chartered 2422 12th Ave Rd #323 Nampa, Idaho 83686 Phone (208) 466-8181 Fax(208)442-7858 Aspen File 13004 lance@AspenEngineers.com P:\2013\13004\Documents\Storm Calcs\Draft 01\1. Storm Calculation Introduction Dutchman.doc Stormwater Management Calculations for Heron Village Apartments 2250 N. Meridian Rd Meridian, Idaho 83642 Table of Contents ASPEN ENGINEERS Section and Description Page 1. Project Description............................................................................................................................. 3 2. Sources of Information....................................................................................................................... 3 3. Applicable Standards.......................................................................................................................... 4 4. Drawing Showing Site Drainage Areas............................................................................................... 5 5. Stormwater Runoff Calculations for Drainage Area#1...................................................................... 6 6. Stormwater Runoff Calculations for Drainage Area #2...................................................................... 8 7. Stormwater Runoff Calculations for Drainage Area #3.................................................................... 10 8. Stormwater Runoff Calculations for Drainage Area#4.................................................................... 12 9. Stormwater Runoff Calculations for Drainage Area #5.................................................................... 14 10. Stormwater Runoff Calculations for Drainage Area#6.................................................................... 16 11. Stormwater Runoff Calculations for Drainage Area#7.................................................................... 18 Appendices A. Runoff Coefficient and Rainfall Intensity.................................................................................. 2 pages B. Infiltration Rate Information.....................................................................................................27 page C. Sand / Grease Trap Cut Sheet.....................................................................................................1 page P:\2013\13004\Documents\Storm Calcs\Draft 01\1. Storm Calculation Introduction Heron Village Apartments.doc Page 2 Stormwater Management Calculations for Heron Village Apartments 2250 N. Meridian Rd Meridian, Idaho 83642 1. Project Description 0 ASPEN 4 ENGINEERS These calculations and attachments provide the background for the design for a new stormwater management system associated with new the new Heron Village Apartments located at 2250 N. Meridian Road in Meridian, Idaho. These calculations, together with the associated civil plans are meant to provide information on the proposed size and location of the seepage beds that will be used to manage stormwater runoff from the proposed building, driveway and parking areas. The proposed stormwater system will use pavement grading and gutters to direct the stormwater runoff to several inlet catch basins and seepage beds. Eight 1,000 gallon sand / grease traps will be used to help remove sediment and oil prior to entering the proposed seepage beds. The distance between the baffles of the sand / grease trap was selected to keep the velocity of the water below 0.50 ft/sec to help provide residence time so sediment can settle in the trap. The seepage beds were sized to handle the anticipated runoff from the 100 -year, 1 -hour storm event using a combination of internal storage in the drain rock and the calculated percolation volume during the 1 -hour design storm event. The seepage beds will be constructed with drain rock underlain by a 6-12" layer of ASTM C-33 filter sand. This will help provide some treatment before the stormwater infiltrates into the subsurface as well as promote infiltration into the subsurface. The site specific soils report indicated an infiltration of 8 in/hr however for the purpose of these calculations an infiltration rate of 4 in/hr was used which is about 1/2 of the rate observed for filter sand. The elevation of seasonal high groundwater was calculated to be at least 10 feet below existing grade using the information provided by Materials Testing & Inspection Geotechnical Engineering Report. 2. Sources of Information The following sources of data were used in preparing these calculations: A. Urban Runoff Control Handbookfor Ada and Canyon Counties, Idaho Ada/Canyon Waste Treatment Management Committee (January 1977). B. Site Layout provided by ULC Management (April 2013). C. Geotechnical Report provided by Materials Testing & Inspection (February 2013). P:\2013\13004\Documents\Storm Calcs\Draft 0111. Storm Calculation Introduction Heron Village Apartments.doc Page 3 Stormwater Management Calculations for Heron Village Apartments 2250 N. Meridian Rd Meridian, Idaho 83642 3. Applicable Standards The following standards were used in preparing these calculations: ASPEN ENGINEERS A. Idaho Standard Public Works Construction Committee. Idaho Standards for Public Works Construction, Current Edition. B. City of Meridian, Ada County, Idaho. Supplementation Specification and Drawings to the Idaho Standards for Public Works Construction. 2008. C. Linsley, Ray, et al, 1992. Water Resources and Environmental Engineering, Fourth Edition, McGraw-Hill, Publishers, Inc. P:\2013\13004\Documents\Storm Calcs\Draft 01\1. Storm Calculation Introduction Heron Village Apartments.doc Page 4 51 Project: Heron Village Apartments Number: 13004ASPEN Given: Subject: Stormwater Runoff Calculations Date: 06/26/13 ENGINEERS By: I- Warnick Page: G 3.1 in/hr 5. RUNOFF CALCULATIONS FOR DRAINAGE AREA 1 A. FIND TIME OF CONCENTRATION (tc) Assume: The time of concentration (tc) for this area is defined as the time needed to reach the inlets from the point that is farthest away. It is assumed the time is 10 minutes. B. FIND PEAK DISCHARGE (Q) Design Storm 100- r, 10 -min Using the Rational Method (Q = CIA) for the 100 -yr, 10 -min storm which is the estimated C. FIND FLOW THROUGH DRAIN PIPE Given: time of concentration. Total Area D Given: 12 in A Pipe flow area = pi * DA2 / 4 = C Runoff Coefficient 0.80 See Appendix A.1 1 Intensity 3.1 in/hr See Appendix A.2 A Drainage Area 0.65 acres See Page 5 Solution: Q Peak Discharge = C*I*A 1.61 cfs C. FIND FLOW THROUGH DRAIN PIPE Given: Total Area D Pipe Diameter 12 in A Pipe flow area = pi * DA2 / 4 = 0.79 ftZ n Roughness coefficient = 0.009 R Hydraulic Radius = D/4 0.250 feet s Slope = 0.40% Solution: q Flow = [1.49 / n * A * RA2/3 * sA0.51 q Flow = 3.26 cfs Check: Flow (q) > Peak Discharge (Q)? YES D. FIND VELOCITY IN GREASE TRAP (v) Given: Grease Trap Size 1,000 gal See Appendix C.1 wt Trap Width 4.00 ft d Distance Between Baffles 12 in a Flow Area = wt*d 4.00 sf Solution: v Velocity = Q/a 0.40 fps Check: Velocity (v) < 0.5 fps? YES P:\2013\13004\Documents\Storm Calcs\Draft 01\3. Storm Calcs - 13004 Project: Heron Village Apartments Number: 13004A S P E N Subject: Stormwater Runoff Calculations Date: 06/26113 ENGINEERS By: L.Warnick Page: E. FIND EXPECTED RUNOFF VOLUME (Vr) AND DESIGN VOLUME (Vd) Design Storm 1 00- r, 1 -hr Using the Rational Method (Q = CIA) for the 100 -yr, 1 -hr storm which is the estimated Solution: Vr Runoff Volume= Q*t 1,872 cf Vd Allow for 15% Sedimentation= Vr*1.15 2,153 cf F. FIND SEEPAGE BED PROPERTIES Given: H Height 5.5 ft Seepage Bed #1 = 5.5'x 12'x 71' W Width 12 ft L Length 71 ft Solution: Vb Bed (Rock) Volume = He*W *L 4,686 cf Vs Storage Volume = Vb*0.4 1,874 cf G. FIND VOLUME FROM INFILTRATION Given: As Area of bottom of infiltration window 852 sf r Infiltration Rate 4 in/hr Assumed t Duration 1 hr Solution: Vi Volume from Infiltration = As*(r/12)*t 284 cf H. CHECK AVAILABLE STORAGE > REQUIRED STORAGE (V) Given: Va Available Storage Volume (Vs + Vi) 2,158 cf Vd Required Volume 2,153 cf This is okay P:\2013\13004\Documents\Storm Calcs\Draft 01\3. Storm Calcs - 13004 time of concentration. Given: C Runoff Coefficient 0.80 See Appendix A.1 I Intensity 1 in/hr See Appendix A.2 A Drainage Area 0.65 acres See Page 5 Q Discharge = C*I*A 0.52 cfs t Storm Duration 1 hr Solution: Vr Runoff Volume= Q*t 1,872 cf Vd Allow for 15% Sedimentation= Vr*1.15 2,153 cf F. FIND SEEPAGE BED PROPERTIES Given: H Height 5.5 ft Seepage Bed #1 = 5.5'x 12'x 71' W Width 12 ft L Length 71 ft Solution: Vb Bed (Rock) Volume = He*W *L 4,686 cf Vs Storage Volume = Vb*0.4 1,874 cf G. FIND VOLUME FROM INFILTRATION Given: As Area of bottom of infiltration window 852 sf r Infiltration Rate 4 in/hr Assumed t Duration 1 hr Solution: Vi Volume from Infiltration = As*(r/12)*t 284 cf H. CHECK AVAILABLE STORAGE > REQUIRED STORAGE (V) Given: Va Available Storage Volume (Vs + Vi) 2,158 cf Vd Required Volume 2,153 cf This is okay P:\2013\13004\Documents\Storm Calcs\Draft 01\3. Storm Calcs - 13004 Project: Heron Village Apartments Subject: Stormwater Runoff Calculations By: L.Warnick 6. RUNOFF CALCULATIONS FOR DRAINAGE AREA 2 A. FIND TIME OF CONCENTRATION (tc) Number: 13004 * A S P E N Date: 06/26/13 ENGINEERS Page: 9 - Assume: The time of concentration (to) for this area is defined as the time needed to reach the inlets from the point that is farthest away. It is assumed the time is 10 minutes. B. FIND PEAK DISCHARGE (Q) Design Storm 100 -yr, 10 -min Using the Rational Method (Q =CIA) for the 100 -yr, 10 -min storm which is the estimated C. FIND FLOW THROUGH DRAIN PIPE Given: Total Area D Pipe Diameter 12 in A Pipe flow area = pi * DA2/4 = 0.79 ft' n Roughness coefficient = 0.009 R Hydraulic Radius = D/4 0.250 feet S Slope = 0.40% Solution: q Flow = [1.49 / n * A * RA2/3 * SAO .51 q Flow = 3.26 cfs Check: Flow (q) > Peak Discharge (Q)? YES D. FIND VELOCITY IN GREASE TRAP (v) Given: Grease Trap Size 1,000 gal See Appendix CA wt Trap Width 4.00 ft d Distance Between Baffles 12 in a Flow Area = wt*d 4.00 sf Solution: v Velocity = Q/a 0.22 fps Check: Velocity (v) < 0.5 fps? YES P:\2013\13004\Documents\Storm Calcs\Draft 01\3. Storm Calcs -13004 time of concentration. Given: C Runoff Coefficient 0.80 See Appendix A.1 I Intensity 3.1 in/hr See Appendix A.2 A Drainage Area 0.36 acres See Page 5 Solution: Q Peak Discharge = C*I*A 0.89 cfs C. FIND FLOW THROUGH DRAIN PIPE Given: Total Area D Pipe Diameter 12 in A Pipe flow area = pi * DA2/4 = 0.79 ft' n Roughness coefficient = 0.009 R Hydraulic Radius = D/4 0.250 feet S Slope = 0.40% Solution: q Flow = [1.49 / n * A * RA2/3 * SAO .51 q Flow = 3.26 cfs Check: Flow (q) > Peak Discharge (Q)? YES D. FIND VELOCITY IN GREASE TRAP (v) Given: Grease Trap Size 1,000 gal See Appendix CA wt Trap Width 4.00 ft d Distance Between Baffles 12 in a Flow Area = wt*d 4.00 sf Solution: v Velocity = Q/a 0.22 fps Check: Velocity (v) < 0.5 fps? YES P:\2013\13004\Documents\Storm Calcs\Draft 01\3. Storm Calcs -13004 Project: Heron Village Apartments Number: 13004 A S P E N Subject: Stormwater Runoff Calculations Date: 06/26/13 ENGINEERS * By: L.Warnick Page: q Intensity E. FIND EXPECTED RUNOFF VOLUME (Vr) AND DESIGN VOLUME (Vd) FDesi n Storm 100- r, 1 -hr Using the Rational Method (Q = CIA) for the 100 -yr, 1 -hr storm which is the estimated time of concentration. Given: C Runoff Coefficient 0.80 See Appendix A.1 I Intensity 1 in/hr See Appendix A.2 A Drainage Area 0.36 acres See Page 5 Q Discharge = C*I*A 0.29 cfs I Storm Duration 1 hr Solution: Vr Runoff Volume= Q*t Vd Allow for 15% Sedimentation= Vr*1.15 1,192 cf F. FIND SEEPAGE BED PROPERTIES Given: H Height 5.5 ft Seepage Bed #2 = 5.5'x 12'x 40' W Width 12 ft L Length 40 ft Solution: Vb Bed (Rock) Volume = He*W*L 2,640 cf Vs Storage Volume = Vb*0.4 1,056 cf G. FIND VOLUME FROM INFILTRATION Given: As Area of bottom of infiltration window 480 sf r Infiltration Rate 4 in/hr Assumed t Duration 1 hr Solution: Vi Volume from Infiltration= As*(r/12)*t 160 cf H. CHECK AVAILABLE STORAGE > REQUIRED STORAGE (V) Given: Va Available Storage Volume (Vs + Vi) 1,216 cf Vd Required Volume 1,192 cf This is okay P:\2013\13004\Documents\Storm Calcs\Draft 01\3. Storm Calcs - 13004 Project: Heron Village Apartments Number: 13004 ASPEN Subject: Stormwater Runoff Calculations Date: 06/26/13 ENGINEERS 0 Roughness coefficient = By: L.Warnick Page: 10 S 7. RUNOFF CALCULATIONS FOR DRAINAGE AREA 3 A. FIND TIME OF CONCENTRATION (tc) Assume: The time of concentration (tc) for this area is defined as the time needed to reach the inlets from the point that is farthest away. It is assumed the time is 10 minutes. B. FIND PEAK DISCHARGE (Q) Design Storm 100- r, 10 -min Using the Rational Method (Q = CIA) for the 100 -yr, 10 -min storm which is the estimated time of concentration. Given: C Runoff Coefficient 0.80 See Appendix A.1 I Intensity 3.1 in/hr See Appendix A.2 A Drainage Area 0.68 acres See Page 5 Solution: Q Peak Discharge = C*I*A 1.69 cfs C. FIND FLOW THROUGH DRAIN PIPE Given: Total Area D Pipe Diameter 12 in A Pipe flow area = pi * DA2/4 = 0.79 ft' n Roughness coefficient = 0.009 R Hydraulic Radius = D/4 0.250 feet S Slope = 0.40% Solution: q Flow = [1.49 / n * A * RA2/3 * SAO .51 q Flow = 3.26 cfs Check: Flow (q) > Peak Discharge (Q)? YES D. FIND VELOCITY IN GREASE TRAP (v) Given: Grease Trap Size 1,000 gal See Appendix CA wt Trap Width 4.00 ft d Distance Between Baffles 12 in a Flow Area = wt*d 4.00 sf Solution: v Velocity= Q/a 0.42 fps Check: Velocity (v) < 0.5 fps? YES P:\2013\13004\Documents\Storm Calcs\Draft 01\3. Storm Calcs - 13004 Project: Heron Village Apartments Number: 13004A S P E N ft Subject: Stormwater Runoff Calculations Date: 06/26/13 ENGINEERS By: L.Warnick _ Page: 11 E. FIND EXPECTED RUNOFF VOLUME (Vr) AND DESIGN VOLUME (Vd) I Design Storm 100 -yr, 1 -hr Using the Rational Method (Q = CIA) for the 100 -yr, 1 -hr storm which is the estimated Solution: Vr Runoff Volume= Q*t 1,958 cf Vd Allow for 15% Sedimentation = Vr*1.15F--2.-25-2—cf---1 F. FIND SEEPAGE BED PROPERTIES Given: H Height 5.5 It Seepage Bed #3 = 5.5'x 10'x 90' W Width loft L Length 90 ft Solution: Vb Bed (Rock) Volume = He*W*L 4,950 cf Vs Storage Volume = Vb*0.4 1,980 cf G. FIND VOLUME FROM INFILTRATION Given: As Area of bottom of infiltration window 900 sf r Infiltration Rate 4 in/hr Assumed I Duration 1 hr Solution: Vi Volume from Infiltration= As*(r/12)*t 300 cf H. CHECK AVAILABLE STORAGE > REQUIRED STORAGE (V) Given: Va Available Storage Volume (Vs + Vi) 2,280 cf Vd Required Volume 2,252 cf This is okay P:\2013\13004\Documents\Storm Calcs\Draft 01\3. Storm Calcs - 13004 time of concentration. Given: C Runoff Coefficient 0.80 See Appendix A.1 I Intensity 1 in/hr See Appendix A.2 A Drainage Area 0.68 acres See Page 5 Q Discharge = C*I*A 0.54 cfs t Storm Duration 1 hr Solution: Vr Runoff Volume= Q*t 1,958 cf Vd Allow for 15% Sedimentation = Vr*1.15F--2.-25-2—cf---1 F. FIND SEEPAGE BED PROPERTIES Given: H Height 5.5 It Seepage Bed #3 = 5.5'x 10'x 90' W Width loft L Length 90 ft Solution: Vb Bed (Rock) Volume = He*W*L 4,950 cf Vs Storage Volume = Vb*0.4 1,980 cf G. FIND VOLUME FROM INFILTRATION Given: As Area of bottom of infiltration window 900 sf r Infiltration Rate 4 in/hr Assumed I Duration 1 hr Solution: Vi Volume from Infiltration= As*(r/12)*t 300 cf H. CHECK AVAILABLE STORAGE > REQUIRED STORAGE (V) Given: Va Available Storage Volume (Vs + Vi) 2,280 cf Vd Required Volume 2,252 cf This is okay P:\2013\13004\Documents\Storm Calcs\Draft 01\3. Storm Calcs - 13004 Project: Heron Village Apartments Subject: Stormwater Runoff Calculations By: L.Warnick 8. RUNOFF CALCULATIONS FOR DRAINAGE AREA 4 A. FIND TIME OF CONCENTRATION (tc) Number: 13004A S P E N Date: 06/26/13 ENGINEERS Page: 12 Assume: The time of concentration (tc) for this area is defined as the time needed to reach the inlets from the point that is farthest away. It is assumed the time is 10 minutes. B. FIND PEAK DISCHARGE (Q) Design Storm 100 -yr, 10 -min Using the Rational Method (Q = CIA) for the 100 -yr, 10 -min storm which is the estimated time of concentration. Given: C Runoff Coefficient 0.80 See Appendix A.1 I Intensity 3.1 in/hr See Appendix A.2 A Drainage Area 0.77 acres See Page 5 Solution: Q Peak Discharge = C*1*A 1.91 cfs C. FIND FLOW THROUGH DRAIN PIPE Given: Total Area D Pipe Diameter 12 in A Pipe flow area = pi * DA2 / 4 = 0.79 fe n Roughness coefficient = 0.009 R Hydraulic Radius = D/4 0.250 feet S Slope = 0.40% Solution: q Flow = [1.49 / n * A * RA2/3 * SAO .51 q Flow = F 3.26 cfs Check: Flow (q) > Peak Discharge (Q)? YES D. FIND VELOCITY IN GREASE TRAP (v) Given: Grease Trap Size 1,000 gal See Appendix CA wt Trap Width 4.00 ft d Distance Between Baffles 15 in a Flow Area = wt*d 5.00 sf Solution: v Velocity= Q/a F ---0-38 —f s Check: Velocity (v) < 0.5 fps? YES P:\2013\13004\Documents\Storm Calcs\Draft 01\3. Storm Calcs -13004 Project: Heron Village Apartments Number: 13004 AS P E N Subject: Stormwater Runoff Calculations Date: 06/26/13ENGINEERS By: L.Warnick Page: 1$ QW E. FIND EXPECTED RUNOFF VOLUME (Vr) AND DESIGN VOLUME (Vd) I Design Storm 100 -yr, 1 -hr Using the Rational Method (Q = CIA) for the 100 -yr, 1 -hr storm which is the estimated Solution: Vr Runoff Volume= Q*t 2,218 cf Vd Allow for 15% Sedimentation = Vr*1.15 2,550 cf F. FIND SEEPAGE BED PROPERTIES Given: H Height 5.5 ft Seepage Bed #4 = 5.5'x 12'x 84' W Width 12 ft L Length 84 ft Solution: Vb Bed (Rock) Volume = He*W*L 5,544 cf Vs Storage Volume = Vb*0.4 2,218 cf G. FIND VOLUME FROM INFILTRATION Given: time of concentration. As Given: 1008 sf r Infiltration Rate C Runoff Coefficient 0.80 See Appendix A.1 I Intensity 1 in/hr See Appendix A.2 A Drainage Area 0.77 acres See Page 5 Q Discharge = C*I*A 0.62 cfs Va t Storm Duration 1 hr Required Volume Solution: Vr Runoff Volume= Q*t 2,218 cf Vd Allow for 15% Sedimentation = Vr*1.15 2,550 cf F. FIND SEEPAGE BED PROPERTIES Given: H Height 5.5 ft Seepage Bed #4 = 5.5'x 12'x 84' W Width 12 ft L Length 84 ft Solution: Vb Bed (Rock) Volume = He*W*L 5,544 cf Vs Storage Volume = Vb*0.4 2,218 cf G. FIND VOLUME FROM INFILTRATION Given: As Area of bottom of infiltration window 1008 sf r Infiltration Rate 4 in/hr Assumed I Duration 1 hr Solution: Vi Volume from Infiltration= As*(r/12)*t 336 cf H. CHECK AVAILABLE STORAGE > REQUIRED STORAGE (V) Given: Va Available Storage Volume (Vs + Vi) 2,554 cf Vd Required Volume 2,550 cf This is okay P:\2013\13004\Documents\Storm Calcs\Draft 01\3. Storm Calcs - 13004 Project: Heron Village Apartments Number: 13004 A S P E N Subject: Stormwater Runoff Calculations Date: 06/26/13ENGINEERS By: L.Warnick Page: I°/ AW 9. RUNOFF CALCULATIONS FOR DRAINAGE AREA 5 A. FIND TIME OF CONCENTRATION (tc) Assume: The time of concentration (tc) for this area is defined as the time needed to reach the inlets from the point that is farthest away. It is assumed the time is 10 minutes. B. FIND PEAK DISCHARGE (Q) Desi n Storm 100- r, 10 -min Using the Rational Method (Q =CIA) for the 100 -yr, 10 -min storm which is the estimated time of concentration. Given: C Runoff Coefficient 0.80 See Appendix A.1 I Intensity 3.1 in/hr See Appendix A.2 A Drainage Area 0.28 acres See Page 5 Solution: Q Peak Discharge = C*I*A 0.69 cfs C. FIND FLOW THROUGH DRAIN PIPE Given: Total Area D Pipe Diameter 12 in A Pipe flow area = pi * DA2/4 = 0.79 fe n Roughness coefficient = 0.009 R Hydraulic Radius = D/4 0.250 feet s Slope = 0.40% Solution: q Flow= [1.491n * A * RA2/3 * sA0.5] q Flow = 3.26 cfs Check: Flow (q) > Peak Discharge (Q)? YES D. FIND VELOCITY IN GREASE TRAP (v) Given: Grease Trap Size 1,000 gal See Appendix CA wt Trap Width 4.00 ft d Distance Between Baffles 12 in a Flow Area = wt*d 4.00 sf Solution: v Velocity = Q/a 0.17 fps Check: Velocity (v) < 0.5 fps? YES P:\2013\13004\Documents\Storm Calcs\Draft 01\3. Storm Calcs - 13004 Project: Heron Village Apartments Number: 13004 S P E NSubject: Given: StormwaterRunoffCalculations Date: 06/26/13GINEERS *2A By: L.Warnick Page: i� Intensity E. FIND EXPECTED RUNOFF VOLUME (Vr) AND DESIGN VOLUME (Vd) Desi n Storm 100 -7r7,1 -=hr Using the Rational Method (Q = CIA) for the 100 -yr, 1 -hr storm which is the estimated time of concentration. Given: C Runoff Coefficient 0.80 See Appendix A.1 I Intensity 1 in/hr See Appendix A.2 A Drainage Area 0.28 acres See Page 5 Q Discharge = C*1*A 0.22 cfs t Storm Duration 1 hr Solution: Vr Runoff Volume= Q*t 806 cf Vd Allow for 15% Sedimentation = Vr*1.15 927 cf F. FIND SEEPAGE BED PROPERTIES Given: H Height 5.5 ft Seepage Bed #5 = 5.5'x 12'x 31' W Width 12 ft L Length 31 ft Solution: Vb Bed (Rock) Volume = He*W*L 2,046 cf Vs Storage Volume = Vb*0.4 818 cf G. FIND VOLUME FROM INFILTRATION Given: As Area of bottom of infiltration window 372 sf r Infiltration Rate 4 in/hr Assumed t Duration 1 hr Solution: Vi Volume from Infiltration= As*(r/12)*t 124 cf H. CHECK AVAILABLE STORAGE > REQUIRED STORAGE (V) Given: Va Available Storage Volume (Vs + Vi) 942 cf Vd Required Volume 927 cf This is okay P:\2013\13004\Documents\Storm Calcs\Draft 01\3. Storm Calcs -13004 Project: Heron Village Apartments Number: 13004A S P E N Subject: StormwaterRunoffCalculations Date: 06/26/13 ENGINEERS By: L.Warnick Page: 1/4 0.250 feet 10. RUNOFF CALCULATIONS FOR DRAINAGE AREA 6 A. FIND TIME OF CONCENTRATION (tc) Assume: The time of concentration (tc) for this area is defined as the time needed to reach the inlets from the point that is farthest away. It is assumed the time is 10 minutes. B. FIND PEAK DISCHARGE (Q) Design Storm 100- r, 10 -min Using the Rational Method (Q = CIA) for the 100 -yr, 10 -min storm which is the estimated time of concentration. Given: C Runoff Coefficient 0.80 See Appendix A.1 I Intensity 3.1 in/hr See Appendix A.2 A Drainage Area 0.67 acres See Page 5 Solution: Q Peak Discharge = C*I*A 1.66 cfs C. FIND FLOW THROUGH DRAIN PIPE Given: Total Area D Pipe Diameter 12 in A Pipe flow area = pi * DA2/4 = 0.79 ft2 n Roughness coefficient = 0.009 R Hydraulic Radius = D/4 0.250 feet s Slope = 0.40% Solution: q Flow = [1.49 / n * A * RA2/3 * SAO .51 q Flow = 3.26 cfs Check: Flow (q) > Peak Discharge (Q)? YES D. FIND VELOCITY IN GREASE TRAP (v) Given: Grease Trap Size 1,000 gal See Appendix CA wt Trap Width 4.00 ft d Distance Between Baffles 12 in a Flow Area = wt*d 4.00 sf Solution: v Velocity= Q/a 0.42 fps Check: Velocity (v) < 0.5 fps? YES P:\2013\13004\Documents\Storm Calcs\Draft 01\3. Storm Calcs - 13004 Project: Heron Village Apartments Number: 13004A S P E N Subject: Stormwater Runoff Calculations Date: 06/26/13 ENGINEERS By: L Warnick Page: E. FIND EXPECTED RUNOFF VOLUME (Vr) AND DESIGN VOLUME (Vd) Design Storm 100 -yr, 1 -hr Using the Rational Method (Q =CIA) for the 100 -yr, 1 -hr storm which is the estimated time of concentration. Given: C Runoff Coefficient 0.80 See Appendix A.1 I Intensity 1 in/hr See Appendix A.2 A Drainage Area 0.67 acres See Page 5 Q Discharge = C*I*A 0.54 cfs t Storm Duration 1 hr Solution: Vr Runoff Volume= Q*t 1,930 cf Vd Allow for 15% Sedimentation = Vr*1.15 2,219 cf F. FIND SEEPAGE BED PROPERTIES Given: H Height 5.5 ft Seepage Bed #6 = 5.5'x 16'x 55' W Width 16 ft L Length 55 ft Solution: Vb Bed (Rock) Volume = He*W*L 4,840 cf Vs Storage Volume = Vb*0.4 1,936 cf G. FIND VOLUME FROM INFILTRATION Given: As Area of bottom of infiltration window 880 sf r Infiltration Rate 4 in/hr Assumed I Duration 1 hr Solution: Vi Volume from Infiltration= As*(r/12)*t 293 cf H. CHECK AVAILABLE STORAGE > REQUIRED STORAGE (V) Given: Va Available Storage Volume (Vs + Vi) 2,229 cf Vd Required Volume 2,219 cf This is okay P:\2013\13004\Documents\Storm Calcs\Draft 01\3. Storm Calcs -13004 Project: Heron Village Apartments Subject: Stormwater Runoff Calculations By: LWarnick 11. RUNOFF CALCULATIONS FOR DRAINAGE AREA 7 A. FIND TIME OF CONCENTRATION (tc) Number: 13004 ASPEN Date: 06/26/13 ENGINEERS Page: I� Assume: The time of concentration (tc) for this area is defined as the time needed to reach the inlets from the point that is farthest away. It is assumed the time is 10 minutes. B. FIND PEAK DISCHARGE (Q) Desi n Storm 100- r,10 -min Using the Rational Method (Q = CIA) for the 100 -yr, 10 -min storm which is the estimated time of concentration. Given: C Runoff Coefficient 0.80 See Appendix A.1 I Intensity 3.1 in/hr See Appendix A.2 A Drainage Area 0.36 acres See Page 5 Solution: Q Peak Discharge = C*1*A 0.89 cfs C. FIND FLOW THROUGH DRAIN PIPE Given: Total Area D Pipe Diameter 12 in A Pipe flow area = pi * DA2 / 4 = 0.79 ft n Roughness coefficient = 0.009 R Hydraulic Radius = D/4 0.250 feet s Slope = 0.40% Solution: q Flow = [1.49 / n * A * RA2/3 * sA0.51 q Flow = 3.26 cfs Check: Flow (q) > Peak Discharge (Q)? YES D. FIND VELOCITY IN GREASE TRAP (v) Given: Grease Trap Size 1,000 gal See Appendix CA wt Trap Width 4.00 ft d Distance Between Baffles 12 in a Flow Area = wt*d 4.00 sf Solution: v Velocity= Q/a 0.22 TDS Check: Velocity (v) < 0.5 fps? YES P:\2013\13004\Documents\Storm Calcs\Draft 01\3. Storm Calcs - 13004 Project: Heron Village Apartments Number: 13004 r-- ASPEN Subject: StormwaterRunoffCalculations Date: 06/'2p6113 ENGINEERS By: I-Warnick Page: _.�..._ IF E. FIND EXPECTED RUNOFF VOLUME (Vr) AND DESIGN VOLUME (Vd) Design Storm 100 -yr, 1 -hr Using the Rational Method (Q = CIA) for the 100 -yr, 1 -hr storm which is the estimated time of concentration. Given: C Runoff Coefficient 0.80 See Appendix A.1 I Intensity 1 in/hr See Appendix A.2 A Drainage Area 0.36 acres See Page 5 Q Discharge = C*I*A 0.29 cfs I Storm Duration 1 hr Solution: Vr Runoff Volume= Q*t 1,037 cf Vd Allow for 15% Sedimentation = Vr*1.15 1,192 cf F. FIND SEEPAGE BED PROPERTIES Given: H Height 5.5 ft Seepage Bed #7 = 5.5'x 12'x 40' W Width 12 It L Length 40 It Solution: Vb Bed (Rock) Volume = He*W*L 2,640 cf Vs Storage Volume = Vb*0.4 1,056 cf G. FIND VOLUME FROM INFILTRATION Given: As Area of bottom of infiltration window 480 sf r Infiltration Rate 4 in/hr Assumed t Duration 1 hr Solution: Vi Volume from Infiltration= As*(r/12)*t 160 cf H. CHECK AVAILABLE STORAGE > REQUIRED STORAGE (V) Given: Va Available Storage Volume (Vs + Vi) 1,216 cf Vd Required Volume 1,192 cf This is okay P:\2013\13004\Documents\Storm Calcs\Draft 01\3. Storm Calcs -13004 Stormwater Management Calculations for Heron Village Apartments 2250 N. Meridian Rd Meridian, Idaho 83642 APPENDIX A 0 ASPEN 6 ENGINEERS RUNOFF COEFFICIENTS AND RAINFALL INTENSITY P:\2013\13004\Documents\Storm Calcs\Draft 01\1. Storm Calculation Introduction Dutchman.doc EXHIBIT "A" Recommended "C" Coefficients for "Rational Method Equation" Peak Rate of Discharge cytptioh of faunOff AT" Runoff Coefficients "G" Business Downtown areas 0.95 Urban neighborhood areas 0.70 Residential Single-family 0.50 Multi -family 0.75 Residential (rural) 0,40 Apartment dwelling areas 0.70 Industrial and Commercial Light areas 0.80 Heavy areas 0.90 Parks, cemeteries 0.10 Playgrounds 0.20 Railroad yard areas 0.20 Unimproved areas 0.10 Streets Asphalt 0.95 Concrete 0.95 Brick 0.85 Drives and walks 0.85 Roofs 0.95 Fields: Sandy soil Flat 2% 0.05 Average 2-7% 0.10 Steep 7% 0.15 Fields: Clay soil Flat 2%u 0.13 Average 2-7% 0.18 Steep 7%n 0.25 Adapted from ASCE (1972 A.1 -- USE 0.80 Shea. , c± No rr CY ANALYSIS BY QUEN ! t 6 Mml• ° as!/�8sr�rrr " a��!!1•r�rrr . am!!!�rlrr�lrrr��■rrrrrr��1� ZONE A RIM ME fI � a��ls►�r■r�►i.��►� . 'rrl� .. a�!llL��'!�ri�il� • as r 0.4 z W F- 02 z J Q .08 .06 z Q .04 M I N U T E 8 ` 3 4 5 8 ! H O U R S 0 U R A T 1 0 Stormwater Management Calculations for Heron Village Apartments 2250 N. Meridian Rd Meridian, Idaho 83642 APPENDIX B INFILTRATION RATE INFORMATION 0 ASPEN ENGINEERS P:t2013\13004\Documents\Storm Calcs\Draft 01\1. Storm calculation Introduction Dutchman.doc Prepared for: r GEOTECHNICAL ENGINEERING REPORT of Heron Village Apartments N. Meridian Rd. £r W. Blue Heron Ln. Meridian, ID MTI File Number B1301229 2791. south Victory View `Nay - Boise. ID 83709 - ;208; 376-4748 • Fax (208) 822-65;5 mti@mYi-id.com • www.mii-id.corn Mr. Cory Swain Heron Village, LLC PO Box 191028 Boise, ID 83719 208-629-7333 Re: Geotechnical Engineering Report Heron Village Apartments Meridian, ID Dear Mr. Swain: 25 February 2013 Page # i of 26 b 134122g_geotech.dvc:x ,.i 91316-11 Tle.. otY s In compliance with your instructions, we have conducted a soils exploration and foundation evaluation for the above referenced development. Fieldwork for this investigation was conducted on 12 February 2013. Data have been analyzed to evaluate pertinent geotechnical conditions. Results of this investigation, together with our recommendations, are to be found in the following report. We have provided a PDF copy and one paper copy for your review and distribution. Often questions arise concerning soil conditions because of design and construction details that occur on a project. MTI would be pleased to continue our role as geotechnical engineers during project implementation. Additionally, IvTFI would be pleased in providing materials testing and special inspection services during construction of this project. If you will advise us of the appropriate time to discuss these engineering services, we will be pleased to meet with you at your convenience. MTI appreciates this opportunity to be of service to you and looks forward to working with you in the future. If you have questions, please call (208) 376-4748. Respectfully Submitted, Materials' Testing & Ins�RO�p� Oy l IN L. at T+ctY OEDER 1' s Z • Fa is • 2At 15 6 964 chroe er, P. '. 6�- �o Reviewed by. Geotechnical Services A rOF 1OP Geotechnical Engineer Copyrigln w ZAl3 Matcrials Testin- K Inspection. Inc. 2791 south Victory View Way • Boise, ID 83709 • (206) 876-4748 - Fax j208) 322-6515 mti@mti-id.com • www,niti-id.com TABLE OF CONTENTS 75 Fwbnmrv70}1 Page 2of26 ^130122:�cNtcch dvcu o"pnig1v*»)uwmc,ia,r,u/";um,r^uo°,Inc 2T91South Victory View Way ° Boise, 08J7U9^ ^ Fax (208022'G5\5 \wnR000cnow-...-~.~—.`---~-^-~^^.~-~.~~.-.,.^~'. _,~,~_~~_,^',,~_._...�] ^^-~— Project Deocdydoo~_^__^~~^~,~,`'_~__~~,~,^,,_,,._~__'___,,_,^'_' .......} &utb"bcudvo � .~.-~~~~..~.~.~'^~~-.`~^.__.__.~~-^.,~'^,'' -'--- � Yurpoon..--,-.--.~^~-~-^~~..^..~.-^~.~,~~,'..^.-'^^~~-~..-- .-~~.~'� 4 Scope oflnve:bgutiou.... ............... ~^~~..... ........ ............................ ......... ....... ...... .......... ...... 4 TNonan�'and ljoihngCnod�iono..-.....-^-.~,.._~-~'_~-~._'~',_,.-_,,,' Exclusive Use '---~-~.--~-.~,__~,^,,_^,__,__,,,^~`,,~`~___'_,,,_,4 -- 4 Report 8oco,nm*ndx,ionare Umi1»Jand 8uWectu>NU»intrqxxtmiou--.,-^..-~.--^.~~-'� EnvironmentalConcerns ........ .... ................................... ..................... ......... .................... .~~~~.-' SITEDESCRIPTION ......... ...... ........ ,...... ........ _,~.^~,_~,_~__^~_~,~_,.......... ~,^~~~,,_,_, 8keAccess.--..`-.-~—',_-'~_,_^,~^~,_~,_~~_~~_~,,__,____^~,^_,~,, 5 Regional 5�okg��-.-~.^'^`--`-^~~`-~^~^'~~-^--^^~^^^^^^~-~^"`^~~~^^'~~~~ 6 General Site Cburu�erod,x-._....'~^~..~~-.^~'.^'-.^~-^~~^~~.-~,,^^~~~~~~ , Regional��hx0roxm|o�yu"d8*nc�on�nry...-.^'—^-~..^~,.-~'`'-.~-^~___^-~� Geo»oimninSruiuD.-..-..-^.'-~~~-^~,~~'.~~,-^,,~_~__^_`__,,__,,^~^,_ 6 SVn..S EXPLORATION ..................... ~'-~'^............... ,~,,`~.... ........ ~,,'_,,^,,~~,_~~~,_^^__ Exploration—and SnopJbn&Procedures ..-....,...~~.^-~'^^'.'~-~.^~^.~.~~^^~,-^'- " y��b�&Yrogrum..-...-...--..~-~~~-^.-~~-~,.^-~~.~~~, Laboratory7 -~~,^~' 3o|uudSodimrruPro�|o.-^.,-..,.----'^~.^-..^^.-'-~~,^.__,__~,__~,_~_� , � Vok�|e(}r&uoicScan .--.-..^.~--.-~-~`'~.-~~.-.^~.--.^,--..-----.,~-^ 8 S/rsHYDROLOGY .--..^-~^-~^~~-^~^~.~..--~-^~.,-~~~-`.'--^.'`-----'-' 8 Groundwater....... ......... ...... ........... ...... ~~.^~~,~~_'_,~,_.......................... .............. ........ _, Soil lu�hzuduoKuus........~~~~.~~~,.--.---.,--~.^--'~-^~-~~_^^,^^^ 8 FOUNDATION, SLAB. AND PAvs/a5wTDISCUSSION AND 8scoaxvpwoar/owS................... -............ ........... 9 Foundation Design Recommendations ....... -................ .-........... ....................... ....... ............ ...... ' Floor Sbh'on-3rudo---.--,-~^.^.-~.~.~-^-----~.-~~..-'.`---~.~-~`.� l0 xccon�,um`dodPuven�m/,Soob"u»-...^....,~.....-.^-~`__^~-_~,,_^_~__~,__ ll Iqox��oPavement 3*cdoux..-.....-....,-.~~'-.~.'~`~^'-~^.—,-..^.,-_.~~~. l| Common Pavement Section Construction Issues .................................... `,^~........... ^~.............. ....... ~l\ CONSranCTmNCONS |osxaT/nwS-...---..~..-~.-'`-~~~~,.~.~.^..`..'~~,~~~--. \2 Bmtbxod'----.-.-..~-~~_,~_~'_^,_,_^,-_~~_^^~_,_^~~~_^,~,_~^~'_ |2 DryWeather .............. ........ ................................ ........ ,-.................... ............................. ... -'~~~. \� WetWeather -....'—~,.-...,._-~~.—'—^~-.^-~..-''^~.~^.-^.~~-.-.--^~ l3 Soft 8ohgrmdoSoils ............. .......... ........ .~............................................................................ ..... .... � l� Frozen 3ohgmdeSoi|s-.,....-.-.-.`.-~-.~.-~-~.-~^~~.---~~~.~^..-~~~. |4 DUoctx,u7iU.,-...,-.,-.^-~~.^-~..^-~.~.-.~'~,,^^~~,~_~,_,,_~~''_,', (4 Backfill u[vYob-...-.._....~-~~.,~^~,'-_~~~__~~_'^^,~,_^.~_~,,_,,. |� Encuvahoos..-....--.,.~~~~^'^.-~~..~~.'--,.^~~^~~.'-.-~,.~-~~^^—~� l� Groundwater Cou�n..-~........--~~.--.~.,.~.~~~^.~.~~-'-^.~.`~.~_-. |� GENERAL Comx/swT8.......°...,..~~.^~~_-.I~.~`^~^.,.-^^~-.`.--~~~-,~~~� \h KEPE8SwCpo.........-..,...~~~.`.-~~~~.~~....^~~^^^~^~,,~^-~.,`.~-~~--' l? 'lppawnl(3s...,-..-...-...--~~~~..-^~.~^,.--~'~.-'~~~~'-^'~~~--'.`.- \8 &nr^ey/nLia...-.....--....~..-.^~'^^-^~~^~,~~~~~..^..'..-..--.....--. 18 Geotechnical General Notes ................. ..................... ~~...... .,~^~~-..... ........ ....... ......... ....... |V Geotechnical Investigation Test Pit Log .............. ............... ............... ....... ................. -...... -....... lo &/\DHTOPuvcmontTbickuo»sDesign Procedures ............................. -........... ..... --.......... ............. l3 P��l:Yicinhy�8ap-....`-....--.-..~~-^^^^~~^,_-~~~_^_______'____ Z� 26P|�e2:Sbr�4up.-,.-..`—.-.-.-..._,~,',_,,_,~~__^_~^,,,,`__^^~,.___ o"pnig1v*»)uwmc,ia,r,u/";um,r^uo°,Inc 2T91South Victory View Way ° Boise, 08J7U9^ ^ Fax (208022'G5\5 MATERIALS TESTING & z,. INSPECTION INTRODUCTION 25 February 2013 Page # 3 of 26 b 1301229__geotech.docx This report presents results of a geotechnical investigation and analysis in support of data utilized in design of structures as defined in the 2009 International Building Code (IBC). Information in support of groundwater and storm water issues pertinent to the practice of Civil Engineering is included. Observations and recommendations relevant to the earthwork phase of the project are also presented. Revisions in plans or drawings for the proposed structures from those enumerated in this report should be brought to the attention of the soils engineer to determine whether changes in foundation recommendations are required. Deviations from noted subsurface conditions, if encountered during construction, should also be brought to the attention of the soils engineer. Project Description The proposed development is within the northern -most portion of the City of Meridian, Ada County, ID, and occupies a portion of the NW 'aSW'f< of Section 6, Township 3 North, Range I East, Boise Meridian. This project will consist of construction of 5 three-story multi -unit apartment structures, without basement levels. Total settlements are limited to 1 inch. Loads of up to 2,000 pounds per lineal foot for wall footings, and column loads of up to 50,000 pounds were assumed for settlement calculations. Additionally., assumptions have been made for traffic loading of pavements. Retaining walls are not anticipated as part of the project. MTI has not been informed of the proposed grading plan. Authorization Authorization to perforin this exploration and analysis was given in the form of a written authorization to proceed from Mr. Cory Swain of Heron Village, LLC to Kevin L. Schroeder of Materials Testing and Inspection, Inc. (MTI), on 5 February 2013. Said authorization is subject to terms, conditions, and limitations described in the Professional Services Contract entered into between Heron Village, LLC and MTI. Our scope of services for the proposed development has been provided in our proposal dated 21 January 2013 and repeated below. Purpose The purpose of this Geotechnical Engineering Report is to determine various soil profile components and their engineering characteristics for use by either design engineers or architects in: • Preparing or verifying suitability of foundation design and placement • Preparing site drainage designs • Indicating issues pertaining to earthwork construction • Preparing light and heavy duty pavement section design requirements Copyright 42013 Materials Testing & Inspection, Inc. 2791 South Victory View Way - Boise, ID 83709 - (208) 376.4748 - Fax (208) 322-6515 mti@lmti-id.com • www,mti-id.com MM Scope of Investigation 25 February 2013 Page 9 4 of 26 J J b 130122g._geotechA)cx The scope of this investigation included review of geologic literature and existing available geotechnical studies of the area, visual site reconnaissance of the immediate site, subsurface exploration of the site, field and laboratory testing of materials collected, and engineering analysis and evaluation of foundation materials. Warranty and Limiting Conditions MTI warrants that findings and conclusions contained herein have been formulated in accordance with generally accepted professional engineering practice in the fields of foundation engineering, soil mechanics, and engineering geology only for the site and project described in this report. These engineering methods have been developed to provide the client with information regarding apparent or potential engineering conditions relating to the site within the scope cited above and are necessarily limited to conditions observed at the time of the site visit and research. Field observations and research reported herein are considered sufficient in detail and scope to form a reasonable basis for the proposes cited above. Exclusive Use This report was prepared for exclusive use of the property owner(s), at the time of the report, and their retained design consultants ("Client'). Conclusions and recommendations presented in this report are based on the agreed-upon scope of work outlined in this report together with the Contract for Professional Services between the Client and Materials Testing and Inspection, Inc. ("Consultant"). Use or misuse of this report, or reliance upon findings hereof, by parties other than the Client is at their own risk. Neither Client nor Consultant make representation of warranty to such other parties as to accuracy or completeness of this report or suitability of its use by such other parties for purposes whatsoever, known or unknown, to Client or Consultant. Neither Client nor Consultant shall have liability to indemnify or hold harmless third parties for losses incurred by actual or purported use or misuse of this report. No other warranties are implied or expressed. Report Recommendation are Limited and Subiect to Misinterpretation There is a distinct possibility that conditions may exist that could not be identified within the scope of the investigation or that were not apparent during our site investigation. Findings of this report are limited to data collected from noted explorations advanced and do not account for unidentified fill zones. unsuitable soil types or conditions, and variability in soil moisture and groundwater conditions. To avoid possible misinterpretations of findings, conclusions, and implications of this report. MTI should be retained to explain the report contents to other design professionals as well as construction professionals. Since actual subsurface conditions on the site can only be verified by earthwork, note that construction recommendations are based on general assumptions from selective observations and selective field exploratory sampling. Upon cora nencement of construction,. such conditions may be identified that required corrective actions, and these required corrective actions may impact the project budget. Therefore. construction recommendations in this report should be considered preliminary, and MI -I should be retained to observe actual subsurface conditions during earthwork construction activities to provide additional construction recommendations as needed. Copyright* 2013 Materials Testing B Inspection, Inc. 2791 South Victory View Way - Boise. ID 83709 • {208) 376-4748 • Fax (208) 322-6515 mti@mtbid.com * www.mti-id.com MATERIALS TESTING & INSPECTION 25 February 2013 Page # 5 of 26 b 130122- ge mh.dom J ,r �t Wit_.., �:..•> i .Ar�pgr J - - Since geotechnical reports are subject to misinterpretation, do not separate the soil logs from the report. Rather, provide a copy, or authorize for their use, of the complete report to other design professional or contractors. This report is also limited to information available at the time it was prepared. In the event additional r information is provided to MTI following publication of our report, it will be forwarded to the client for evaluation in the form received. Environmental Concerns Comments in this report concerning either onsite conditions or observations, including soil appearances and odors, are provided as general information. These continents are not intended to describe, quantify, or evaluate environmental concerns or situations. Since personnel, skills, procedures, standards, and equipment differ, a geotechnical investigation report is not intended to substitute for a geoenvironmental investigation or a Phase II/III Environmental Site Assessment. If the potential for petroleum or hazardous materials contamination or other environmental hazards relating to the site exists. MTI must be informed prior to the commencement of the geotechnical investigation. If environmental services are needed, MTI can provide, via a separate contract, those personnel who are trained to investigate and delineate soil and coater contamination.. SITE DESCRIPTION Site Access Access to the site may be gained via Interstate 84 to the Meridian Road off ramp (Exit #44). Travel north on S. Meridian Road then S. Mann Street approximately 1'/< miles to E. Fairview. Turn left, heading west for a block back to Meridian Road then turn north again and travel % mile to Blue Heron Lane. The proposed development is immediately to the south and west of this intersection, and presently consists of both developed and undeveloped properties. The location is depicted in site map plates included in the Appendix. Regional Geology The site is located within the Boise Valley, which is directly underlain by a thick sequence of alluvial sands and gravels typically deposited on basalt formations. These sediments are loosely named the Boise River Gravels and were deposited as river floodplain and stream overwash from the Boise River. These gravel deposits tend to have imbricated well-rounded clasts, poor sorting and crude stratification of beds of gravel and lenses of cross -bedded sand suggesting deposition in braided channels. Boise River Gravels consist of unconsolidated clay, silt, sand, gravel, and cobbles. These gravels have been subdivided into smaller units based on their age and are exposed as distinct alluvial terraces. Five of these terraces are well exposed in the Boise area and range in age from Middle Pleistocene to Holocene (Recent) (0 - 0.9 million years ago). The site lies on the Whitney Terrace, the second terrace above the currently defined floodplain (Othberg and Stanford, 1992). Copyright ro) 2013 Materials Testing+ & Inspection, hic. 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 * Fax (208) 322-6515 rnti@mti-id.00m - www.mti-id.com MATERIALS v TESTING & General Site Characteristics 25 February 2013 Page 4 6 of 26 Is 130122g_,.geotecit.docx This proposed development consists of approximately 5.5 acres of relatively flat and level terrain. Throughout the majority of the site, surficial soils consist of fine-grained lean clay soils or disturbed surficial materials. Vegetation primarily consists of grasses, thick weed growths, and Iimited landscape areas associated wvith the two remaining residences. The site is bisected by varied irrigation works that also lay along portions of the perimeter. A shallow swale has been cut in the northwestern -most lot of the property. Two residential structures remain along the western -most edge of the site fronting Meridian Road, and varied fencing also remains along portions of parcel perimeters. Regional drainage is north and west through the Boise River drainage. Storm water drainage for the site is achieved predominately by percolation through surficial soils. No significant intermittent off-site storm water should drain onto the project. Storm water drainage collection and retention systems are not in place on the project site, however they do exist within the adjacent road sections, Regional Site Climatology and Geochemistry According to the Western Regional Climate Center, the average precipitation for Treasure Valley is on the order of 10 to 12 inches per year, with an annual snowfall of approximately 20 inches and a range from 3 to 49 inches. The monthly mean daily temperatures range from 21'F to 95° F with daily extremes ranging from -25° F to 111° F. Winds are generally from the northwest or southeast with an annual average wind speed of approximately 9 miles per hour (mph) with a maximum of 62 mph. Soils and sediments in the area are primarily derived from siliceous materials and exhibit low electro -chemical potential for corrosion of metals or concretes. Local aggregates are generally appropriate for Portland cement and lime cement mixtures. Surface waters, groundwaters, and soils in the region typically have pH levels ranging from 7.2 to 8.2. Geoseismic Setting Soils on site are classed as Site Class D in accordance with Chapter 16 of the 2009 edition of the IBC. Strictures constructed on this site should be designed per IBC requirements for such a seismic classification. Our investigation did not reveal hazards resulting from potential earthquake motions including: slope instability, liquefaction, and surface rupture caused by faulting or lateral spreading. Incidence and anticipated acceleration of seismic activity in the area is low. SOILS )C' xPLORATION Exploration and Sampling Procedures Field exploration conducted to determine engineering characteristics of subsurface materials included a reconnaissance of the project site and investigation by test pit. Test pit sites were located in the field by means of visual approximation from on-site features or known locations and are presumed to be accurate to within a few feet. Upon completion of investigation, each test pit was backfilled with loose excavated Copyright CJ 2013 Maicrials Testing & Inspection, Inc. 2791 South Victory. View Way • Boise, ID 83709 • (208) 376-4748 - Fax (208) 322-6515 mti@ml;-id.com • www rot-id.com 1t � 25 February 2013 Page # 7 of 26 bI30122g eeoteAdoa materials. Re -excavation and compaction of these test pit areas are required prior to construction of overlying structures. In addition, samples were obtained from representative soil strata encountered. Samples obtained have been visually classified in the field by professional staff, identified according to test pit number and depth, placed in scaled containers, and transported to our laboratory for additional testing. Subsurface materials have been described in detail on logs provided in the Appendix. Results of field and laboratory tests are also presented on these logs. MTI recommends that these logs not be used to estimate fill material quantities. Laboratory Testing Program Along with our field investigation, a supplemental laboratory testing program was conducted to determine additional pertinent engineering characteristics of subsurface materials necessary in an analysis of the anticipated behavior of the proposed structures. Laboratory tests were conducted in accordance with current applicable American Society for Testing and Materials (ASTM) specifications, and results of these tests are to be found on the accompanying logs located in the Appendix. The laboratory testing program for this report included: Atterberg Limits Tests - ASTM D4318 and Grain Size Analysis - ASTM CI 17/C136. Soil and Sediment Profile The profile below represents a generalized interpretation for the project site. Note that on site soils strata, encountered between test pit locations, may vary from the individual soil profiles presented in the logs, which can be found in the Appendix. The materials encountered during exploration were quite typical for the geologic area mapped as the Whitney Terrace Gravels. Surficial soils were predominately lean clays. These clays were dark brown in color, generally exhibited moisture contents of slightly moist to moist, and had consistencies of medium stiff to stiff. Organic materials were noted to extend throughout this layer. Beneath this horizon in each test pit, silts that were light brown or brown, usually slightly moist to dry, and varied from medium stiff to hard were encountered. In most of the test pits the silts exhibited some degree of calcium carbonate cementation, usually occurring as weak or vveak to moderate in strength. Within test pits 1 and 4, a thin bed of silty sand was noted at the transition from the fine grained soils to the more granular gravel sediments. This sediment was brown, slightly moist, and medium dense. Below these silty sands and below the silt horizons in the other test pits, silty to poorly graded gravel sediments were encountered. These appeared to grade back and forth with depth, eventually grading to poorly graded sandy gravels. The presence of the silts through this layer allowed for the occurrence of seeps that were found in test pits I and 5. Clasts within the gravels tended to be roughly 6 inches or less in size. However, some larger Clasts were noted within the test pit logs. Competency of test pit walls varied little across the site. In general, fine grained soils remained stable while more granular sediments exhibited some degree of sloughing. Moisture contents will also affect wall competency, and saturated soils and sediments will have a tendency to slough when under load and unsupported. Copyright oC 2013 Materials Testing & Inspection, Inc:. 27q'i South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 rrti@roti-id.com • www.mti-id.com tMATERIALS TESTING £r _110 INSPECTION Volatile Organic Scan 25 February 2013 Page 3# 8of26 ni?o122g geolechdocx No environmental concerns were identified prior to commencement of the investigation. Therefore, soils obtained during on -.site activities were not assessed for volatile organic compounds by portable photoionization detector. Samples obtained during our exploration activities exhibited no odors or discoloration typically associated with this type contamination. No groundwater was encountered. SITE HYDROLOGY Existing surface drainage conditions are defined in the General Site Characteristics section. Information provided in this section is limited to observations made at the time of the investigation. Either regional or local ordinances may require information beyond the scope of this report. Groundwater During this field investigation, groundwater was not encountered in test pits advanced to a maximum depth of 16.8 feet bgs. Soil moistures in the test pits were generally slightly moist to dry through the shallower soils across the site. Within the silty to poorly -graded sands, soil moistures were usually slightly moist. However, the variable amount of silt through some of the shallower gravels was sufficient to allow limited water to perch, and show as seeps through this formation. In the vicinity of the project site, groundwater levels are controlled in large part by residential and commercial irrigation activity and leakage from nearby canal. Maximum groundwater elevations likely occur during the later portion of the irrigation season. A series of geotechnical investigations were performed within roughly mile of this site from 2004 to 2007. During these investigations, evidence of groundwater was generally encountered at depths of I 1 to 15 feet of depth. Based on evidence of this investigation and background knowledge of the area. MTI estimates groundwater depths to remain greater than approximately 10 to 11 feet bgs throughout the year. However, this depth can be confirmed through long-term groundwater monitoring of the site via the piezometer installed in test pit I. If desired, MTI is available to perform this monitoring. Soil Infiltration Rates Soil permeability, which is a measure of the ability of a soil to transmit a fluid, was not tested in the field. Given the absence of direct measurements, for this report an estimation of infiltration is presented using generally recognized values for each soil type and gradation. Of soils comprising the generalized soil profile for this study, lean clay and silt soils generally offer little permeability, with typical hydraulic infiltration rates of less than 2 inches per hour; though calcitun carbonate cementation noted through most of the silt formations may reduce this value to near zero. Silty sand sediments usually display rates of 4 to 8 inches per hour. Silty to poorly graded gravel sediments typically exhibit infiltration values in excess of 12 inches per hour; though seep encountered in test pits 1 and 5 indicates that infiltration is limited within the silty gravel sediments. Infiltration testing is generally not required within the poorly graded sandy gravel sediments because of their free -draining nature. Copyright 1i 2013 Materials'icsung K Inspection, Inc. 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 Fax (208) 322-6515 mti@mti-id.com • www:mtHd.com C -`°m MATERIALS TESTING & INSPECTION 25 February 2013 Page # 9 of 26 b 130122g_geotech.docx . It is recommended that infiltration facilities constructed on the site be extended into native sandy gravel sediments. Excavation depths of approximately 10 to 12 feet bgs should be anticipated to expose these sandy gravel sediments, Because of the high soil permeability, ASTM C33 filter sand, or equivalent, should be incorporated into design of infiltration facilities. An infiltration rate of 8 inches per hour should be used in design. Actual infiltration rates should be confirmed at the time of construction. FOUNDATION, SLAB, AND PAVEMENT DISCUssioN AND RECOMMENDATIONS Various foundation types have been considered for support of the proposed structures. Two requirements must be met in the design of foundations. First, the applied bearing stress must be less than the ultimate bearing capacity of foundation soils to maintain stability. Second, total and differential settlement must not exceed an amount that will produce an adverse behavior of the superstructure. Allowable settlement is usually exceeded before bearing capacity considerations become important; thus, allowable bearing pressure is normally controlled by settlement considerations. Considering subsurface conditions and the proposed construction, it is recommended that the structure be founded upon conventional spread footings and continuous wall footings. Total settlements should not exceed 1 inch if the following design and construction recommendations are observed. Foundation Design Recommendations Based on data obtained from the site and test results from various laboratory tests performed, MTI recommends following guidelines for the net allowable soils bearing capacity: Soil Bearing Canacitv 'It is recommended that MTI personnel verify the bearing soil suitability for each structure at the time of construction. The following sliding frictional coefficient values should be used: 1) 0.35 for footings bearing on native cemented silts and 2) 0.35 for footings bearing on granular structural fill. A passive lateral earth pressure of 349 pounds per square foot (psf) should be used for cemented silt soils; though the maximum material size should not be greater than 4 inches in diameter and silt soils must be non -plastic. For compacted sandy gravel fill, a passive lateral earth pressure of 496 psf should be used. Copyright til 2013 Matcriais Testing & Inspection. lnc. 2791 South Victory View Way • Boise, ID 83709 - (208) 376-4748 • Fax (208) 322-6515 mti@mti-id.com • www.mti-id.com Footings must bear on competent, undisturbed, z 2,0001bs/ft native silt or cemented silt soils, or compacted Not Required for structural fill, Existing lean clay soils must be Native Soil A 1/3 increase is allowable completeljy removed from below foundation for short-term loading, elements. Excavation depths of approximately 1 95% for Structural Fill which is defined by seismic foot bgs should be anticipated to expose proper events or designed wind bearing soils. speeds. 'It is recommended that MTI personnel verify the bearing soil suitability for each structure at the time of construction. The following sliding frictional coefficient values should be used: 1) 0.35 for footings bearing on native cemented silts and 2) 0.35 for footings bearing on granular structural fill. A passive lateral earth pressure of 349 pounds per square foot (psf) should be used for cemented silt soils; though the maximum material size should not be greater than 4 inches in diameter and silt soils must be non -plastic. For compacted sandy gravel fill, a passive lateral earth pressure of 496 psf should be used. Copyright til 2013 Matcriais Testing & Inspection. lnc. 2791 South Victory View Way • Boise, ID 83709 - (208) 376-4748 • Fax (208) 322-6515 mti@mti-id.com • www.mti-id.com 25 February 2013 Page # 10 01726 b 1301221geotech.docx Footings should be proportioned to meet either the stated soil bearing capacity or the 2009 IBC minimum requirements. Total settlement should be limited to approximately 1 inch, and differential settlement should be limited to approximately 'l2 inch. Objectionable soil types encountered at the bottom of footing excavations should be removed and replaced with structural till. Excessively loose or soft areas that are encountered in the footing subgrade will require over -excavation and backfilling with structural till. To minimize the effects of slight differential movement that may occur because of variations in character of supporting soils and seasonal moisture content. MTI recommends continuous footings be suitably reinforced to make them as rigid as possible. For frost protection the bottom of external footings should be 30 inches below finished grade. Floor Slab -on -Grade Native clay soils are moderately plastic and will be susceptible to shrink/swell movements associated with moisture changes. Areas of the site within the proposed structures should be excavated to sufficient depths to expose lean clay. The clay soils should be scarified to a depth of 6 inches and re -compacted between 92 percent and 98 percent of the maximum density as determined by ASTM D698. The moisture content should range from i to 4 percentage points above optimum. Structural fill should be placed as soon as possible after re -compaction of clay soils in order to limit moisture loss within the upper clays. Ground surfaces should be sloped away from structures at a minimum of 5 percent for a distance of 10 feet to provide positive drainage of surface water away from buildings. Grading must be provided and maintained following construction. Uncontrolled fill may be encountered associated with the residential properties soon to be vacated and with the irrigation systems developed through the varied parcels MTI recommends that these fill soils be excavated to a sufficient depth to expose competent native soils MTI personnel should be present during excavation to identify these materials. Organic, loose, or obviously compressive materials must be removed prior to placement of concrete floors or floor -supporting fill. In addition, the remaining subgrade should be treated in accordance with guidelines presented in the )'earthwork section. Areas of excessive yielding should be excavated and backfilled with structural fill. Fill. used to increase the elevation of the floor slab should meet requirements detailed in the Structural Fill section. Fill materials must be compacted to a minimum 95 percent of maximum density as determined by ASTM D1557. A free -draining granular mat (drainage fill course) should be provided below slabs -on -grade. This should be a minimurn of 4 inches in thickness and properly compacted. The mat should consist of a sand and gravel mixture, complying with Idaho Standards for Public Works Construction (ISPWC) specifications for'/ -inch ("type 1) crushed aggregate. A moisture -retarder should be placed beneath floor slabs to minimize potential ground moisture effects on moisture -sensitive floor coverings. The moisture -retarder should be at least 15 -mil in thickness and have a permeance of less than 0.01 US perms as determined by ASTM E96. Placement of the moisture -retarder will require special consideration with regard to effects on the slab -on -grade. The granular mat should be compacted to no less than 95 percent of maximum density as determined by ASTM D1557. Upon request, MTI can provide further consultation regarding installation. Copyright 0 2013 Materials Testing B Inspection, Inc. 2791" South Victory View Way • Boise. ID 83709 • (208) 378-4748 • Fax (208) 322-8515 mti@mti-d.com • www.mti-id.com i � L Recommended Pavement Sections 25 February 2013 Page 4 11 of 26 b 1 3,0122e geotech docx MTI has made asstmiptions for traffic loading variables based on the character of the proposed construction. The client shall review and understand these assumptions to make sure they reflect intended use and loading of pavements both now and in the future. Based on experience with soils in the region, a subgrade California Bearing Ratio (CBR) value of 5 has been assumed for near -surface non-cemented silt soils on site. The following are minimum thickness requirements for assured pavement function. Depending on site conditions. additional work, e.g. soil preparation, may be required to support construction equipment. These have been listed within the Soft Subgrade Soils subsection. Flexible Pavement Sections The AASHTO design method has been used to calculate the following pavement sections. Calculation sheets provided in the Appendix indicate the soils constant, traffic loading, traffic projections, and material constants used to calculate the pavement sections. MTI recommends that materials used in the construction of asphaltic concrete pavements meet requirements of the ISPWC Standard Specification for Highway Construction. Construction of the pavement section should be in accordance with these specifications and should adhere to guidelines recommended in the section on Construction Considerations. AASHTO Flexible Asphaltic Concrete 25 Inches 3.0 Inches Crushed Aggregate Base 4.0 Inches 6.0 Inches Structural Subbase 8.0 Inches 12,0 Inches Compacted Subgrade Not Required Not Required alt is recommended that MTI personnel verify subgrade competency at the time of construction. Asphaltic Concrete: Asphalt mix design shall meet the requirements of ISPWC, Section 810 Class III plant mix. Materials shall be placed in accordance with ISPWC Standard Specifications for Highway Construction. Aggregate Base: Material complying with ISPWC Standards for Crushed Aggregate Materials. Structural Subbase: Material should comply with the requirements detailed in the Structural Fill section of this report except that the maximum material diameter is no more than'/: the component thickness. Common Pavement Section Construction Issues The subgrade upon which above pavement sections are to be constructed must be properly stripped, inspected, and proof -rolled. Proof rolling of subgrade soils should be accomplished using a heavy rubber - tired, fully loaded, tandem -axle dump truck or equivalent. Verification of subgrade competence by MTI personnel at the time of construction is required. Fill materials on the site must demonstrate the indicated compaction prior to placing material in support of the pavement section. MTI anticipates that pavement areas will be subjected to moderate traffic. MT] does not anticipate pumping material to become evident during Copyright @ 2013 Materials 'resting & Inspection, Ino. 2791 South Victory View Way • Boise, ID 83709 o (208) 376-4748 - Fax (208) 322-6515 mtl@niti-id.com • www.mti-id.coni 25 February 2013 Page # 12 of 26 b 130122 g_geotech. docx t uovssrt�._r.t - G."0*0" ,.r rs* .� 'J .-c ,S,rs,. �,1,.� , compaction, but subgrade silts near and above optimum moisture contents may tend to pump. Pumping or soft areas must be removed and replaced with structural fill, Fill material and aggregates in support of the pavement section must be compacted to no less than 95 percent of the maximum dry density as determined by ASTM D698 for flexible pavements and by ASTM DI 557 for rigid pavements. If a material placed as a pavement section component cannot be tested by usual compaction testing methods, then compaction of that material must be approved by observed proof rolling. Minor deflections from proof rolling for flexible pavements are allowable. Deflections from proof rolling of rigid pavement support courses should not be visually detectable. MTI recommends that rigid concrete pavement be provided for heavy garbage receptacles. This will eliminate damage caused by the considerable loading transferred through the small steel wheels onto asphaltic concrete. Rigid concrete pavement should consist of Portland Cement Concrete Pavement (PCCP) generally adhering to ITD specifications for Urban Concrete. PCCP should be 6 inches thick on a 4 -inch drainage fill course (see Floor Slab -on -Grade section), and should be reinforced with welded wire fabric. Control joints must be on 12 -foot centers or less. CONSTRUCTION CONSIDERATIONS Recommendations in this report are based upon structural elements of the project being founded on competent undisturbed, native cemented silt soils or compacted structural fill. Structural areas should be stripped to an elevation that exposes these soil types. Earthwork Excessively organic soils, deleterious materials, or disturbed soils generally undergo high volume changes when subjected to loads, which is detrimental to subgrade behavior in the area of pavements, floor slabs, structural fills, and foundations. Mature trees, brush, and thick grasses with associated root systems were noted at the time of our investigation. It is recommended that organic or disturbed soils, if encountered, be removed, and wasted or stockpiled for later use. Stripping depths should be adjusted in the field to assure that the entire root zone or disturbed zone (plow depths) or topsoil are removed prior to placement and compaction of structural fill materials, Exact removal depths should be determined during grading operations by a qualified geotechnical representative, and should be based upon subgrade soil type, composition, and firmness or soil stability, If underground storage tanks, underground utilities, wells, or septic systems are discovered during construction activities, they must be decommissioned then removed or abandoned in accordance with governing Federal, State, and local agencies. Excavations developed as the result of such removal must be backfilled with structural fill materials as defined in the Structural Fill section. MTI should oversee subgrade conditions (i.e., moisture content) as well as placement and compaction of new fill (if required) after native soils are excavated to design grade. Recotmnendations for structural fill presented in this report can be used to minimize volume changes and differential settlements that are detrimental to the behavior of footings, pavements, and floor slabs. Sufficient density tests should be performed to properly monitor compaction. For structural fill beneath building structures, one in-place density test per lift for every 5,000 square feet is recommended. In parking and driveway areas, this can be decreased to one test per lift for every 10,000 square feet. Copyright @ 2013 h1atcrials resting & Inspection, Inc. 2791 south Victory View Way • Boise, IA 83709 • (206) 3?6-4748 • Fax (200) 322-6515 mti@mti-id.com - www.niti-id.com w Pry Weather 25 February 2013 Page # 13 of 26 b 130122g_geotech.doc� J C,'....,?.... If construction is to be conducted during dry seasonal conditions, many problems associated with soft soils may be avoided. However, some rutting of subgrade soils may be induced by shallow groundwater conditions related to springtime runoff or irrigation activities during late summer through early fall. Solutions to problems associated with soft subgrade soils are outlined in the Soft Subgrade Soils section. Problems may also arise because of lack of moisture in native and fill soils at time of placement. This will require the addition of water to achieve near -optimum moisture levels. Low -cohesion soils exposed in excavations may become friable, increasing chances of sloughing or caving. Measures to control excessive dust should be considered as part of the overall health and safety management plan. Wet Weather If construction is to be conducted during wet seasonal conditions (commonly from mid-November through May), problems associated with soft soils must be considered as part of the construction plan. During this time of year, fine-grained soils such as silts and clays will become unstable with increased moisture content, and eventually deform or rut. Additionally, constant low temperatures reduce the possibility of drying soils to near optimum conditions. Soft Subgrade Soils Shallow fine-grained subgrade soils high in moisture content should be expected to pump and rut under construction traffic. During periods of wet weather, construction may become very difficult if not impossible. The following recommendations and options have been included for dealing with soft subgrade conditions: • Track -mounted vehicles should be used to strip the subgrade of root matter and other deleterious debris. Heavy rubber -tired equipment should be prohibited from operating directly on the native subgrade and areas in which structural fill materials have been placed. Construction traffic should be restricted to designated roadways that do not cross, or cross on a limited basis, proposed roadway or parking areas. • Construction roadways on soft subgrade soils should consist of a minimum 2 -foot thickness of large cobbles of 4 to 6 inches in diameter with sufficient sand and fines to fill voids. Construction entrances should consist of a 6 -inch thickness of clean, 2 -inch minimum, angular drain -rock and must be a minimum of 10 feet wide and 30 to 50 feet long. During the construction process, top dressing of the entrance may be required for maintenance. • Scarification and aeration of subgrade soils can be employed to reduce the moisture content of wet subgrade soils. After stripping is complete, the exposed subgrade should be ripped or disked to a depth of 1'/z feet and allowed to air dry for 2 to 4 weeks. Further disking should be performed on a weekly basis to aid the aeration process. • Alternative soil stabilization rv.ethods include use of geotextiles, lime, and cement stabilization. MTI is available to provide recommendations and guidelines at your request. Copyright.@'013 Materials'I'esting& Inspection, tnc: 2791 South Victory View Way • Boise, ID &9709 • (203) 376-4748 - Fax (203) 322.6515. mti@mti-d.com • www.mti-id.com MATERIALS TESTING & INSPECTION 25 February 2013 Page 4 14 ol'26 h 130122e, geotech.docx `:7 E�i.:e?i71, c ,::; U ,.,. .. ::a< 'J".�,.,7Si.>; .. n. ;.,rig-. Frozen Subgrade Soils Prior to placement of structural fill materials or foundation elements, frozen subgrade soils must either be allowed to thaw or be stripped to depths that expose non -frozen soils and wasted or stockpiled for later use. Stockpiled materials must be allowed to thaw and return to near -optimal conditions prior to use as structural fill. Structural Fill Soils recommended for use as structural fill are those classified as GW, GP, SW, and SP in accordance with the Unified Soil Classification System (USCS) (ASTM D2487). Use of silty soils (USCS designation of GM, SM, and ML) as structural fill may be acceptable. However, use of silty soils (GM, SM, and ML) as structural fill below footings is_prohibited. These materials require very high moisture contents for compaction and require a long time to dry out if natural moisture contents are too high and may also be susceptible to frost heave under certain conditions. Therefore these materials can be quite difficult to work with as moisture content, lift thickness, and compactive effort becomes difficult to control. If silty soil is used for structural fill, lift thicknesses should not exceed 6 inches (loose), and fill material moisture must be closely monitored at both the working elevation and the elevations of materials already placed. Following placement, silty soils must be protected from degradation resulting from construction traffic or subsequent construction. Recommended granular structural fill materials, those classified as GW, GP, SW, and SP, should consist of a 6 -inch minus select, clean, granular soil with no more than 50 percent oversize (greater than'/ -inch) material and no more than 12 percent fines (passing No. 200 sieve). These fill materials should be placed in Iayers not to exceed 12 inches in loose thickness. Prior to placement of structural fill materials, surfaces must be prepared as outlined in the Construction Considerations section. Structural fill material should be moisture - conditioned to achieve optimum moisture content prior to compaction. For structural fill below footings, areas of compacted backfill must extend outside the perimeter of the footing for a distance equal to the thickness of fill between the bottom of foundation and underlying soils, or 5 feet, whichever is less. All fill materials must be monitored during placement and tested to confirm compaction requirements, outlined below, have been achieved. Each layer of structural fill must be compacted, as outlined below: • Below Structures and Rigid Pavements: A minimum of 95 percent of the maximum dry density as determined by ASTM D1557. • Below Flexible Pavements: A minimum of 92 percent of the maximum dry density as determined by ASTM D1557 or 95 percent of the maximum dry density as determined by ASTM D698. The ASTM D1557 test method must be used for samples containing up to 40 percent oversize (greater than %-inch) particles, If material contains more than 40 percent but less than 50 percent oversize particles, compaction of fill must be confirmed by proof rolling each lift with a 10 -ton vibratory roller (or equivalent) until the maximum density has been achieved. Density testing must be performed after each proof rolling pass until the in-place density test results indicate a drop (or no increase) in the dry density, defined as the maximum density or "break over" point. The number of required passes should be used as the requirement on the remainder of fill placement. Material should contain sufficient fines to fill void spaces, and must not contain more than 50 percent oversize particles. Copyright @ 2013 Materials Testing &I Inspcetion, Inc. 2791 South Victory View Way - Boise, ID 83709 • {208) 376-4748 • Fax (208) 322-6515 mti@mti-id.com - www.mti-id.com Backfill of Walls 25 February 2013 Page 9 15 of 26 b130122& aeotech-doca Backfill materials must conform to the requirements of structural fill, as defined in this report. For wall heights greater than 2.5 feet, the maximum material size should not exceed 4 inches in diameter. Placing oversized material against rigid. surfaces interferes with proper compaction, and can induce excessive point loads on walls. Backfill shall not commence until the wall has gained sufficient strength to resist placement and compaction forces. Further, retaining walls above 2.5 feet in height shall be backfilled in a manner that will limit the potential for damage from compaction methods and/or equipment. It is recommended that only small hand -operated compaction equipment be used for compaction of backfill within a horizontal distance equal to the height of the wall, measured from the back face of the wall. Backfill should be compacted in accordance with the specifications for structural fill, except in those areas where it is determined that future settlement is not a concern, such as planter areas. In nonstructural areas, backfill must be compacted to a firm and unyielding condition. Excavations Shallow excavations that do not exceed 4 feet in depth may be constructed with side slopes approaching vertical. Below this depth, it is recommended that slopes be constructed in accordance with Occupational Safety and Health Administration (OSHA) regulations, section 1926, subpart P. Based on these regulations, on-site soils are classified as type "C" soil, and as such, excavations within these soils should be constructed at a maximum slope of I Moot horizontal to I foot vertical (1 %:H:1 V) for excavations up to 20 feet in height. Excavations in excess of 20 feet will require additional analysis. Note that these slope angles are considered stable for short-term conditions only, and will not be stable for lone -term conditions. During our subsurface exploration, test pit sidewalls generally exhibited little indication of collapse; however, sloughing of fill materials and native granular sediments from test pit sidewalls was observed. For deep excavations, native granular sediments cannot be expected to remain in position. These materials are prone to failure and may collapse, thereby, undermining upper soils layers. This is especially true when excavations approach depths near the water table. Care must be taken to ensure that excavations are properly backfilled in accordance with procedures outlined in this report. Shallow soil cementation (caliche) was observed throughout much of the site and may cause difficulties during foundation development and utility placement. Cemented soils should be anticipated throughout the site at depths of 2 to 5 feet bgs. Groundwater Control Groundwater was not encountered during the investigation and is anticipated to be below the depth of construction. Special precautions may be required for control of surface runoff and subsurface seepage. It is recommended that runoff be directed away from open excavations. Silty or clayey soils may become soft and pump if subjected to excessive traffic during time of surface runoff. Ponded water in construction areas should be drained through methods such as trenching, sloping, crowning grades, nightly smooth drum rolling, or installing a French drain system. Additionally, temporary or permanent driveway sections should be constructed if extended wet weather is forecasted. Copyright G 2013 Materials Testing & Inspection, Inc, 2791 South Victory View Way • Boise, 16 83709 • (208) 376-4748 - Fax {2081322-6515 mti@mti-id.com + www.mti-id.com ' (MATERIALS TESTING & INSPECTION 25 February 2013 Page 0 16 of 26 It 130122g_f-eotech.docx U'.' GENERAL COMMENTS When plans and specifications are complete, or if significant changes are made in the character or location of the proposed structures, consultation with MTI should be arranged as supplementary recommendations may be required. It is recommended that suitability of subgrade soils and compaction of structural fill materials be verified by MTI personnel prior to placement of structural elements. Additionally, monitoring and testing should be performed to verify that suitable materials are used for structural fill and that proper placement and compaction techniques are utilized. Copyright @ 201, Materials resting& Inspection. Inc. 2791 South Victory View Way • Boise, 16 83709 • (208j 376-4748 • Fax (208) 322-6515 mtiC inti-id.com . wwwmti-id.com MATERIALS TESTING & iNSPECTi®N REFERENCES 25 February 201 3) Page ;# 17 of 26 b i 30122g_geotech.aoex American Society for Testing and Materials (ASTM) (2004). Standard Test Method for Materials Finer than 75 -um (No. 200) Sieve in Mineral Aggregates by Washing_ASTM 0117. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2006). Standard Test Method for Sieve Analysis of Fine and Coarse Ag_gt-egates: ASTM C136. West Conshohocken, PA: ASTM. American Society for Testing and Materials (AS"I'M) (2007). Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort D698. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2009). Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort D1557. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2007). Standard Test Methods for California Bearing Ratio, ASTM D1883. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2011). Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System) D2487. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2010). Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils: ASTM D4318. West Conshohocken, PA: ASTM. American Society of State Highway and Transportation Officials (AASHTO) (1993). AASHTO Guide for Design of Pavement Structures 1993, Washington, D. C.: AASHTO. Collett, R. A., U. S. Department of Agriculture. Soil Conservation Service. (1980). Soil Survey of Ada County Area, Idaho. Washington, DC: U. S. Government Printing Office. Desert Research Institute. Western Regional Climate Center. [Online] Available: <http://www,wrcc.dri.edLLI> (2013). International Building Code Council (2009). International Building Code, 2009. Country- Club Hills, IL: Author. Local Highway Technical Assistance Council (LI-ITAC) (2010). Idaho Standards for Public Works Construction, 2010. Boise, iD: Author. Othberg, K. L. and Stanford, L. A., Idaho Geologic Society (1992). Geologic Map of the Boise Valley and Adjoining Area Western Snake River Plain, Idaho. (scale 1:100,000. Boise, Idaho: Joslyn and Morris. U. S. Department of Agriculture, Natural Resource Conservation Service. Web Soil Survey. [Online] Available: <http://websoilsurvey.nres.usda.gov/app/> (2013). U. S. Dept. of Labor, Occupational Safety and Health Administration. "CFR 29. Part 1926, subpart 1': Safety and Health Regulations for Construction. Excavations. (1986)". [Online] Available: < www.osha.gov> (2013). U. S. Geological Survey. (2011). National Water Information System: Web Interface. [Online] Available: <http://waterdata.usgs.govinwis> (2013). Copyright @ 2013 Materials Testing @ Inspection, Inc. 2791 South Victory View Way • Boise, ID 83709 - (208) 376-4748 - Fax (208) 322-5515 mti@mti-id.com • www.tnti-id.com CMATERIALS TESTING & INSPECTION 25 February 2013 Page # 18 of 26 b 130122g_geotech.does _ .: 1'!rv5,. ` 'n"'. ,i it ,� .J APPENDICES ACRONYM LIST AASHTO: American Association of State highway and Transportation Officials ACCP: Asphalt Cement Concrete Pavement ACRD: Ada County highway District ASTM: American Society for Testing and Materials AU: Auger sample bgs: below ground surface CB: Carbide bit CBR: California Bearing Ratio D: natural dry unit weight, pcf DB: diamond bit DM: Dames & Moore sampling tube GS: grab sample IBC: International Building Code ISPWC: Idaho Standards for Public Works Construction ITD: Idaho Transportation Department LL: Liquid Limit M: water content MSL: mean sea level N: Standard "N" penetration: blows per foot, Standard Penetration Test NP: nonplastic PCCP: Portland Cement Concrete Pavement PERM: vapor permeability PI: Plasticity Index PID: photoionization detector PVC: polyvinyl chloride QC: cone penetrometer value, unconfined compressive strength, psi QP: Penetrometer value, unconfined compressive strength, tsf Qu: Unconfined compressive strength, tsf SPT: Standard Penetration Test (140:pound hammer falling 30 in. on a 2:in. split spoon) SS: split spoon (I318:in. inside diameter, 2:in. outside diameter, except where noted) ST: shelby tube (3: in. outside diameter, except where noted) USCS: Unified Soil Classification System USDA: United States Department of Agriculture UST: underground storage tack V: vane value, ultimate shearing strength, tsf WT: apparent groundwater level Copyright © 2013 Materials Testing& Inspection. Ine. 2791 South Victory View Way • Boise, 10 83709 • (208) 378-4748 • Fax l208,322-6515 mti@mti-id.com • www.mti-id.eom GEOTECHNICAL GENERAL NOTES 25 Febniary 201 1 Page # 19 of 26 6130122g F ,elotecli.doi Mr_ 'NW'ZX YN 1, Coarse -Grained Soils SPT Blow Counts (N) Fine -Grained Soils SPT Blow Counts (N) Very Loose; <4 Very Soft: <2 Loose: 4-10 Soft: 2-4 Medium Dense: 10-30 Medium Stiff. 4-8 Dense: 30-50 Stiff. 8-15 Very Dense: >50 Very Stiff: 15-30 asses No.4 sieve Hard: >30 Cop,tight @ 2013 Materials Testing & InsIviol Inc 2791 South Victory View Way - Boise, ID 83709 - (208) 376-4748 - Fax (208) 322-65115 mti@mti-id.com - Description Field Test Weakly Crumbles or breaks with handling or slight Finger pressure Moderately Crumblesor beaks, with considerable Soils <50% coarse fraction passes No.4 sieve GP Poorly -graded gravels; gravel/sand mixtures with little or no fines Strongly Will not crumble or break with finger Sand & Sandy Soils >50% coarse fraction pressure Cop,tight @ 2013 Materials Testing & InsIviol Inc 2791 South Victory View Way - Boise, ID 83709 - (208) 376-4748 - Fax (208) 322-65115 mti@mti-id.com - WE M0 1,19R741*2 Gravel & Gravelly GW Well -graded gravels; gravel/sand mixtures with little or no fines Coarse -Grained Soils <50% Soils <50% coarse fraction passes No.4 sieve GP Poorly -graded gravels; gravel/sand mixtures with little or no fines GM Silty gravels: poorly -graded gravel/san&lsilt mixtures GC Clayey gravels; poorly -graded gravel/sand/clay mixtures Sand & Sandy Soils >50% coarse fraction sw Well -graded sands; gravelly sands with little or no fines passes No.200 sieve SP Poorly -graded sands; gravelly sands with little or no fines SM Silty sands; poorly -graded sand/gravel/silt mixtures SC Clayey sands; poorly -graded sand/gravel/clay mixtures asses No.4 sieve Fine Grained Silts & Clays LL < 50 ML Inorganic silts; sandy, gravelly or clayey silts CL Lean clays; inorganic, gravelly, sandy, or silty, low to medium -plasticity clays OL Organic, low -plasticity clays and silts Soils >50% passes Noi sieve Silts & Clays LL > 50 MH Inorganic, elastic silts: sandy, gravelly or clavey elastic silts CH Fat clays; high -plasticity, inorganic clays OH Organic, medium to high -plasticity clays and silts Highly Organic Soils PT Peat, humus, hydric soils with high organic content Cop,tight @ 2013 Materials Testing & InsIviol Inc 2791 South Victory View Way - Boise, ID 83709 - (208) 376-4748 - Fax (208) 322-65115 mti@mti-id.com - MATERIALS 25 February 2013 TESTING & Page 20 of 26 INSPECTION I, 130122g_geotnch.doc.c CIE rc n.i,ewa� -rti.- M D GE07'ECIINIC:AI, INVESTIGATION TEST PIT LOG Test Pit Log #: TP -1 Date Advanced: 12 Feb 2013 Logged by: Kevin L. Schroeder, P.G. Excavated by: Struckman's Backhoe Service Location: See Site Map Plates Depth to Water Table: Not Encountered Total Depth: 16.8 Feet bgs Notes: Piezometer installed to 16.8 feet bgs. Depth Field Description and Sample Sample Depth Lab Feet bgs) USCS Soil and Sediment Classification Type (Feet bgs) Qp Test ID Lean Clay (CL): Dark brown, slightly moist, 0.0-1.1 medium stiff to stiff. --Orgastic material throughout. --Grades to the horizon below. Silt (ML): Light brown, slightly moist to dry, 1.1-4.0 medium stiff to hard --Weak calcium carbonate cementation from 1.9 to 2.4feet bgs. 4.0-6.2 Silty Sand (SM): Brown, slightly moist, medium dense. Silty to Poorly Graded Sandy Gravel (GM/GP): Brown, slightly moist to wet, medium dense to dense. 6.2-16.8 --Seeps at 9.2 feet bgs. --Gravel clasts are sub -rounded to rounded predominately minus 6 inches in sire with minor clasts to 18 inches. Copyright sJ 2013 Materials 'I esting & Inspection, Inc. 2791 South Victory View Way • Boise, ID 63709 • (208) 376-4748 - Fax (203) 322-6515 mii@mti-id.com • www.mti-id.corr, 1 � Y 25 February 2013 Page 4 21 of 26 I 130122g_geotech.doex ❑ _ ""j Bf:• :i -J GEOTECHNICAL INVESTIGATION TEST PFT LOG Test Pit Log 4: TP -2 Date Advanced: 12 Feb 2013 Logged by: Kevin L. Schroeder, P.G. Excavated by: Struckman's Backhoe Service Location: See Site Map Plates Depth to Water Table: Not Encountered Total Depth: 8.8 Feet bgs Depth Field Description and Sample Sample Depth Qp Lab (Feet bgs) USCS Soil and Sediment Classification Type (Feet bgs) Qp Test ID Lean Clay (CL): Dark brown, slightly moist, 0.0-0.7 medium stiff to stiff. 1.0-1.5 --0r anic material throughout. Silt (ML): Light brown, slightly moist to dry. 0.7-4.4 very stiff to hard. ?.5-4.5+ --Weak to moderate calcium carbonate cementation from 3. t to 4.4 feet bgs. 4.2-8.3 Silty to Poorly Graded Sandy Gravel (GM/GP): Red brown to brown, slightly moist, 4.4-8.8 medium dense to vety dense. --Gravel clasts are sub -rounded to rounded. predominately mimes 6 inches in size. Test Pit Log �: TP -3 Date Advanced: 12 Feb 2013 Logged by: Kevin L. Schroeder, P.G. Excavated by: Struckman's Backhoe Service Depth to Water Table: Not Encountered Location: See Site Map Plates Total Depth: 8.3 Feet bgs Depth Field Description and Sample Sample Depth Lab (Feet bgs) USCS Soil and Sediment Classification Type (Feet bgs) Qp Test ID Lean Clay (CL): Dark brown, slightly moist to 0.0-0.7 moist, medium stiff to stiff I.0-1.5 --Dr anic material throughout. Silt (ML): Brown, slightly moist to dry, stiff to 0.7-4.2 hard --Weak to moderate calcium carboncue 2.045+ cementation from 2.6 to 3.3 feet bgs. Silty to Poorly Graded Sandy Gravel 4.2-8.3 (Glvll(JP): Red brown to brown. slightly moist, medium dense to eery dense. Copyright �J 2013 Matenals Testing C Inspcetion, Inc, 2791 South Victory View Way • Boise. ID 53709 - (208) 376-4748 • Fax (208) 322-6515 mflLtrnti-id com • wvww.rnti-iB.com t t� 25 February 2013 Page ,r 22 of 26 tr130I �'e_geouch docx GEOTECHNICAL INVESTIGATIONTEST PIT LOG Test Pit Log,",: TP4 Date Advanced: 12 Feb 2013 Logged by: Kevin L. Schroeder, P.G. Excavated by: Struckman's Backhoe Service Location: See Site Map Plates Depth to Water Table: Not Encountered Total Depth: 8.3 Feet bgs Depth Field Description and Sample Sample Depth Qp Lab Feet bgs) USCS Soil and Sediment Classification Type (Feet bgs) Test ID Lean Clay (CL): Dark brown, slightly moist to 0 0-0.6 moist, medium stiff f to stiff. 0.0-1.0 1.0-I.5 _Organic material throughout. --Grades to the horizon below. 0.6-5.8 Silt (ML): Light brown, slightly moist to dry, 2.5-4.5+ verb stiff to hard. 5.8-6.8 Silty Sand (SM): Brown, slightly moist, 4.5-8.1 medium dense. Silty to Poorly Graded Sandy Gravel 6.8-83 (GM/GP): Brown, slightly, moist to wet, medium dense to dense. Test Pit Log 4: TP -5 Date Advanced: 12 Feb 2013 Logged by: Kevin L. Schroeder, P.G. Excavated by: Struekman's Backhoe Service Location: See Site Map Plates Depth to Water Table: Not Encountered Total Depth: 8.1 Feet bgs Depth Field Description and Sample Sample Depth Qp Lab Feet bas) USCS Soil and Sediment Classification Type (Feet bgs) Test ID Lean Clay (CL): Dark brown, slightly moist to 0.0-0.9 moist, medium stiff to stiff 0.0-1.0 1.0-1.5 --Organic material throughoutGS --Grades to the horizon below. 0.9-4.5 Silt (ML): Light brown, slightly moist to wet, 2.0-4.5+ stiff to hard. Silty to Poorly Graded: Sandy Gravel 4.5-8.1 (GM/GP): Brown, slightly moist to wet, medium dense to very dense. --Seeps at 6.8,feet bgs. Copmelit On 2013 kintenitts testing A inspection, Inc, 2791 South Victory View Way • Boise, ID 83709 • (1208) 376.474.8 • Fax (208) 322-6515 mti§mti-id.com • www.mti-id.com MATERIALS TESTING & INSPECTION 25 February 2013 Page N 23 of 26 h I 3rl22g_gcotech,docx Ll E CI L_I -*ch! ifC: J i.0 C r,�,:., 3 AASHTO PAVEMENT THICKNESS .DESIGN PROCEDURES Copyright 4) 2013 Materials Testing & Inspection. Inc. 2791 South Victory View Way . Boise. ID 83708 • (208) 376-4748 * Fax (208) 322-6515 roti@mti-id.corn - www roti-id.com Pavement Section Design Location: Proposed Heron t5(Inge Apartments. Nu Truck Access Average Daily Traffic Count: 212 All Lanes& Beth Directions Design Life: 20 Years Percent of Traffic in Design Lane: 100% Terminal Seviceability Index (Pt): 2.5 Level of Reliability: 95 Subgrade CBR Value: 5 Subgrade Mr; 7,500 Calculation of Design -18 kip ESAIs Daily Cao"th Load Design Trnffic Rate Factors ESALs Passenger Cars: 70 2.0% 0.0008 497 Buses: 2 2.0% 0.6806 12,072 Panel & Pickup Trucks: 30 2.0% 0.0122 3246 2 -Axle, 6 -Tire Trucks: 3 2.0% 0.1890 5.028 Concrete Trucks: 1.0 2.0% 4.4800 39,731 Diunp Trucks: 0 2.0% 3.6300 0 Tractor Semi Trailer Trucks: 0 2.0% 2.3719 0 Double Trailer Trucks 0 2.0% 2.3187 0 Heavy Tractor Trailer Combo Trucks: 0 2.0% 29760 0 Average Daily Traffic in Design Lane: 106 Total Design Life 18 -kip ESALs: W574 Actual Log (ESALs): 4.782 Trial SN: 2.41 Trial Log ([SAI.$): 4.878 This number most be equal to or greater than the Actual Log Pavement Section Design SN: 2.41 This number must be equal to or greater than the Trial SN. Design Depth Structural Drainage Inches Coefficient Coefficient Asphaltic Concrete, 2.50 0.42 Ain Asphalt Treated Base: 0.00 0.25 n/a Cement Treated Base. 0.00 0.17 Ala Crushed Aggregate Base: 4.00 0.14 1.0 Pit Run Aggregate Subgrade: 8.00 0.10 1.0 Special Aggregate Subgrade: 0.00 0.09 0.9 Copyright 4) 2013 Materials Testing & Inspection. Inc. 2791 South Victory View Way . Boise. ID 83708 • (208) 376-4748 * Fax (208) 322-6515 roti@mti-id.corn - www roti-id.com SPANiGLEbrz 6f AaqN Id N� -91:5�"' -7- V q N1 1'S3AV N IN CHANTIt.LY'AVE �A A� Nj Lt1CHN E;ipWAY f NS U�M£RBROi3K Pt N N SHEEPH90 AVE _ fi, --I' � 1, —P—,AMETHYST-' ' -;, - N AVEA N SAPPHIREOLF k AV E i I aAV DNISSOaO AVd N g ;� 11 ,-( �1, r I AVE zlikco% N quEk7f*'WM -1-1 " % , --c � 1� 11 1% iS I IOW,)hk , g " -,, AEAIC!j aAf Xnd MO�jlaX N' N" N $HIRE Pt. WAY 3AV =&Eni LINT ?N11SNOWY IGOOSE-WAY ,'� -k?ji,AVE71, to NT a 10 N1 INAlUd N .RAVHIOTgN -&a"],M K 4 N WOCVk L4 . ..... COO AVE CAP* ............. VM GO> A adY-1 N Ucl 1lJM VY CL j',kVM70dbkL MO�UV N,,'I, a VC 4 cc INcl UY, L e3 RAV N BAV Vb#rIll N &Q, A*W)ih3 N 3AVVNVZMN ERIDIXN RD N OWN N . tJ0� W 2ND� ST -LS -d-MVW N N 5pptN(i 51 CH? 1 4TH ST k4 P 'ISF Embp U; -- I, IUIPI A_ , / 2N MIDTOWN'ST' Ila �Jal AVM H:6kNatl-dD N 3 4 N 0 rA xi Ila 'ERE OR, qjv KENM, YEN_ eL -WR-1Y.f AVE e N .... ... . ..... —NOT44 AVE IBLOSSOM PL JIS Hie nn NW 'AV 1,1111, - Td HIG MN NW 12TH ST, BAV I-LLI I MN tuhi0 Wini'ST .4 CLEARBKC* PL 0, 4) Nwlitnl STjo ST _NW 'AVE �N N LINDER iNWS j --NU R RE TS N Id DL7vd3A N TAIA. PINE Pl. 41169 N Ul it z ;g Or E t9 m z E E2 E Ul NW m E :510 z �3&6fW N : VW -N ...... Q-1 ML, N, ; g N AVE(��. Uy, j iIAVawl SPANiGLEbrz 6f AaqN Id N� -91:5�"' -7- V q N1 1'S3AV N IN CHANTIt.LY'AVE �A A� Nj Lt1CHN E;ipWAY f NS U�M£RBROi3K Pt N N SHEEPH90 AVE _ fi, --I' � 1, —P—,AMETHYST-' ' -;, - N AVEA N SAPPHIREOLF k AV E i I aAV DNISSOaO AVd N g ;� 11 ,-( �1, r I AVE zlikco% N quEk7f*'WM -1-1 " % , --c � 1� 11 1% iS I IOW,)hk , g " -,, AEAIC!j aAf Xnd MO�jlaX N' N" N $HIRE Pt. WAY 3AV =&Eni LINT ?N11SNOWY IGOOSE-WAY ,'� -k?ji,AVE71, to NT a 10 N1 INAlUd N .RAVHIOTgN -&a"],M K 4 N WOCVk L4 . ..... COO AVE CAP* ............. VM GO> A adY-1 N Ucl 1lJM VY CL j',kVM70dbkL MO�UV N,,'I, a VC 4 cc INcl UY, L e3 RAV N BAV Vb#rIll N &Q, A*W)ih3 N 3AVVNVZMN ERIDIXN RD N OWN N . tJ0� W 2ND� ST -LS -d-MVW N N 5pptN(i 51 CH? 1 4TH ST k4 P 'ISF Embp U; -- I, IUIPI A_ , / 2N MIDTOWN'ST' Ila �Jal AVM H:6kNatl-dD N 3 4 N 0 rA xi Ila 'ERE OR, qjv KENM, YEN_ eL -WR-1Y.f AVE e N .... ... . ..... —NOT44 AVE IBLOSSOM PL JIS Hie nn NW 'AV 1,1111, - Td HIG MN NW 12TH ST, BAV I-LLI I MN tuhi0 Wini'ST .4 CLEARBKC* PL 0, 4) Nwlitnl STjo ST _NW 'AVE �N N LINDER iNWS j --NU R RE TS N Id DL7vd3A N TAIA. PINE Pl. 41169 N Ln zor- Lazu w aEro n 9W V, 0 E L4 09 2 ---- -- - -- ------------ _TF-711 'A Stormwater Management Calculations for Heron Village Apartments 2250 N. Meridian Rd Meridian, Idaho 83642 APPENDIX C SAND / GREASE TRAP CUT SHEETS P:\2013\13004\Documents\Storm Calcs\Draft 01\t. Storm Calculation Introduction Dutchman.doc 0 ASPEN ENGINEERS CA .L OUTLET FLOW I 'Pill Exxvivol"I . . a. PLAN VIEW ALLOWED CONSTRUCTION JOI OUTLET BAFFLE WALL ®EL.B �EL. OUT.® ` EL IN7 —INLET BAFFLE WALL (see calculations and plan for distance between baffles) SECTION A—A NOTES AO DESIGN LOAD: AASHTO HS -25 HIGHWAY LOADING. O ALL REINFORCING STEEL SHALL BE GRADE 60. DETAILED DRAWING OF A PRECAST BOX OR A POURED IN PLACE BOX DESIGN MUST BE APPROVED BY THE ENGINEER PRIOR TO CONSTRUCTION. QD HEIGHT OF OUTLET BAFFLE WALL AND LENGTH OF INLET BAFFLE WALL DETERMINED BY TANK CAPACITY AND FLOW RATE. OE BEFORE THESE BOXES ARE USED THE APPLICATION MUST BE APPROVED BY THE ENGINEER. OF MANHOLE FRAME, COLLAR AND COVER SHALL BE PER SD -616 AND SD -617. © PROVIDE STEPS WHEN THE DISTANCE FROM TOP OF MANHOLE FRAME TO TOP OF BOX EXCEEDS 24'. 0 LEGEND INLET FLOW 1O MANHOLE FRAME AND COVER PER SO -617 (TYPICAL) Q LOCATION AND FL ELEV. PER DESIGN PLANS. (TYPICAL) 3O Hs12" USE GRADE RINGS (TYPICAL) 12"<H 24" USE 24" DIA RCP RISER 24"<H 120" USE MANHOLE CONE & 45" Dl� RAERS. ® EL. IN > EL. B BY 1" MIN. EL. OUT < EL B BY 1" MIN. UNLESS OTHERWISE APPROVED BY ACHD 5O WATERTIGHT SEAL © PRECAST BOX MANUFACTURER SHALL MARK FLOW DIRECTION AND LABEL INLET OR OUTLET ON SIDE OF BOX ACHD 2010 Revisions IDAHO STANDARDS STANDARD DRAWING FOR RUTSAND AND GREASE TRAP NO. CONSTRUCTION oN S (ACHD SUPPLEMENif