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HomeMy WebLinkAboutCC - Drainage Report Prepared For: Gasser Land Development Subdivision No. 1 GFI — Meridian Investments LLC, ACHD Meridian, Idaho Storm Drainage Report ,SONAL ENG Digitally signed by Q� Lachlin Kinsella g 60 Date:2025.12.07 12:33:14-07'00' s� 12/7/25 o Q 0 /A/ c. K\N� Prepared By: Jeff Duplechain, EIT Project Engineer Reviewed By: Lachlin Kinsella, P.E. Project Manager KM Engineering, LLP 5725 North Discovery Way Boise, I D 83713 208.639.6939 Ikinsella@kmengllp.com Ian December 2025 E N G I N E E R I N G Project No: 25-129 TABLE OF CONTENTS Introduction ................................................................................................................................. 1 ProjectDescription ...................................................................................................................... 1 SiteDescription............................................................................................................................... 1 Scopeand Methods........................................................................................................................ 1 Existing Drainage Conditions .......................................................................................................... 1 Proposed Drainage Conditions and Analysis .................................................................................. 1 Inletand Gutter Capacities ............................................................................................................. 2 SeepageBeds.................................................................................................................................. 2 Summary......................................................................................................................................... 3 APPENDICES Appendix A - Figures Figure 1 - Vicinity Map Figure 2 - Post-Development Drainage Map Figure 3 - Storm Water Improvement Plans Appendix B - Tables Table 1 - Peak Flow Rates and Runoff Volumes Appendix C - Calculations Post-Development 25-year Calculations Post-Development 100-year Calculations Inlet and Gutter Capacities Seepage Bed Calculations Appendix D - Geotechnical Engineering Report & Groundwater Data Geotechnical Engineering Report— Proposed Mixed Use Development (MTI, 03/06/2020) Test Pit Map Ground Water Monitoring Data INTRODUCTION The purpose of this report is to show that the storm drainage facilities for the proposed Gasser Land Development Subdivision No. 1 (Project) are designed to meet Ada County Highway District (ACHD) and the water quality requirements of the Idaho Department of Environmental Quality (DEQ). This report has been prepared at the request of the developer, GFI — Meridian Investments II LLC. PROJECT DESCRIPTION The project consists of two public roadways, with right turn lanes, along N. Ten Mile Rd. that will be utilized during future commercial and residential development of the site. A right turn lane along W. Franklin Rd. is also proposed for future use. The proposed improvements include roadways, sidewalks, lot grading, and site utilities. SITE DESCRIPTION The project site is located north east of the intersection of W. Franklin Rd. and N.Ten Mile Rd. in Meridian, Idaho. See Appendix A, Figure 1 for a vicinity map of the project. SCOPE AND METHODS The stormwater system for the Project has been designed per the 2017 ACHD Stormwater Policy. The Rational Method is the standard method for small catchments and was used to calculate post-development peak runoff rates and runoff volumes. The Rational Method provided in the ACHD calculation sheets was used to calculate the storm water volumes and flow rates for this project (see Appendix C - Calculations). Flow rates and storm volumes were established for each basin for the 25-year and 100-year storms. Refer to Appendix B, Table 1 - Peak Flow Rates and Runoff Volumes, for a summary of flow rates and runoff volumes. Calculations for the seepage beds were completed to verify capacity. EXISTING DRAINAGE CONDITIONS The pre-project watershed consists primarily of agricultural land that was previously irrigated through open channels and includes two drainage basins. The irrigation wastewater and stormwater runoff are currently being collected to the southwest and northeast of the Project site. Along W. Franklin Rd., there are existing storm water inlets capturing runoff from the road and connecting to an existing storm water system. PROPOSED DRAINAGE CONDITIONS AND ANALYSIS The proposed drainage system improvements consist of roadway inlets and gutters, sand and grease traps, manholes, seepage beds, and a sediment box. The post-development site was broken into four (4) basins as shown in Appendix A, Figure 2- Post-Development Drainage Map. For land use type and runoff coefficients (0.1—open space, 0.95 — impervious) for each basin, refer to ACHD calculations in Appendix C. Each basin was delineated according to the tributary area draining to each drainage structure 1 or facility such as gutter, catch basin inlet, etc. For individual sub-basin peak flow calculations, in addition to combined sub-basin peak flows used for downstream facility sizing and analysis, see Table 1 (Peak Flow Rates and Runoff Volumes). The proposed drainage basins include all the proposed roadways, curb and gutters, and sidewalks, as well as landscaping strips. The basins were also delineated based off of future roadway extensions into the site. Storm water runoff consists of overland sheet flow over short grass that is conveyed with curb and gutter to catch basin inlets. The storm water runoff is then conveyed from the catch basin inlets to the proposed seepage beds. There are two new right-turn lanes on N. Ten Mile Rd. and one right-hand lane on W. Franklin Rd. The improvements along N. Ten Mile Rd. will include relocating a double catch basin inlet and replacing one single catch basin inlet to new curb and gutter locations. The improvements along W. Franklin Rd. will include relocating one catch basin inlet and one sediment box to the new curb and gutter location. The existing drainage basins and facilities should be maintained for the offsite roadway improvements. INLET AND GUTTER CAPACITIES The catch basin inlets should be built per the details shown on the civil construction plans. There is a total of five (5) single inlets, one (1) double inlet, and one (1) double inlet that includes a combination sediment box and inlet. The gutter capacity of the proposed roadways was verified to ensure that overtopping of the curb would not occur in the 25-year and 100-year storm event (refer to Appendix C— Inlet and Gutter Capacities). SEEPAGE BEDS The Project includes two (2) seepage beds (SB #1 and SB #2) that should be built per the details shown on the civil construction plans. Based on our calculations,the seepage beds are adequately sized to ensure that no ponding should occur on the surface and the volume required to retain the 100-year storm event are met. Once the sizes of the seepage beds were calculated, the times necessary for 90% of the 100-year storm events to be infiltrated into the ground were calculated at less than 48- hours for each of the seepage beds. The design infiltration rate at 8 in/hr was used in the calculations and is based on the recommended rate for poorly graded gravel sediments from the geotechnical report prepared by MTI. The calculations included with this report show the volumes that are required to be retained for the 100-year storm and the drain time through the bottom of the seepage beds. Refer to Appendix B, Tables and Appendix C, Seepage Bed Calculations. 2 SUMMARY This report determines that the Project storm water design sizing and analysis should conform to ACHD and the water quality requirements of the Idaho Department of Environmental Quality (DEQ). The post-development storm water runoff for the proposed roadway, curb and gutters, sidewalks, and landscaping strips should be completely retained onsite through the proposed seepage beds. The existing drainage basins and facilities should be maintained for the offsite roadway improvements along N. Ten Mile Rd. and W. Franklin Rd. 3 APPENDIX A - FIGURES om FFFF (11111111111mv Im - - - - - - - - - - - - - - PROJECT W.FRANKLIN RD. 0 cJ G z o 77- Lu a � a (z x x o6 C m a 0 a O N 0 N n N c-I W Z Y Z 2 5 3 0 a z v 0 1000 2000 3000 N N Plan Scale: 1" = 1000' lam E N G I N E E R I N G 5725 NORTH DISCOVERY WAY X PHONE(08)639-6939 GASSER LAND DEVELOPMENT SUBDIVISION NO. 1 o kmengllp.com MERIDIAN, ID a i DATE: DECEMBER 2025 > PROJECT: 25-129 SHEET: VICINITY MAP 1 OF 1 a DRAINAGE LEGEND DESIGN POINTS A BASIN DESIGNATION 2 INLET#2 ------- Er ------ 2.5 AREA IN ACRES 3. INLET#3 w'sD 3ssD �3c:so— — — — — — — — — — — — — — — — — — — — — #5 , r_____ ____ DESIGN POINT 5 INLET# 7 N.TEN MILE RD. _ _ _ _ _ r _ _ _ _ _ _ _ # s. INLErs##sa& s6 EXISTING GRADE CONTOUR 8. SST#17 ------- --- -- 1=D- ,zs ,zs ,z sD 2470— 9. SOT#2. -- — --_ 10. #ENT BOX#1 111.SB 1 _ � —f' _ ` _ FINISHED GRADE CONTOUR 12.56#2 2568 3 _�. — / ---- ------ —�--- J r' ® \ 8 9 / / - - 2570 zo 2571 //----- ———./ BE B7 A2 EP ^M 0.29 0.29 -- —2573---------------1----- ------------------� 0.33 Al — `( 0.34 2573 \ i w Lu -' H Q � m 7 { \ / — z H Z Id—Id—Idia �H Z N � 9 / V a —— / / J W Q LU a L.I..I O °C Oa r u, LLJ Q z PUBLIC STREET "A" AND PUBLIC STREET "B" - SITE w W w F- 0 40 80 120 Q F Plan Scale:1"=40' z N U Q 0J CO Lu Q x U x A N L x �\x �_zs ----- _ h z '2583� Q U R w r r 5 M�0 � `Lh Ih� � rY�^ ryM0 2y81 ---j"-- j-- ------r--.� _--_-_-_— - - - - -/-m--_-_- N W.FRANKLIN RD. / / / z 5 16'S0 I.-SD to"SD 18'SD�18"SD �(8"SD �'SD 8'SD 98•SD �+✓D 18"SD 8" O 6 y�D �L 6�D 'SD— \ \ \ ^\ \\ \\ \\ ENGINEERING LL 5725 NORTH DISCOVERY WAY W \ \ \ \ BOISE,IDAH083713 C I \ PHONE1208I 639-6939 Q kmengllp.com z DESIGN BY: LCK RIGHT TU D RN LANE - W. FRANKLIN RD. RECKEDB < AWN Y: ,AD C LCK Q 51 5 0 30 60 90 DATE: DECEMBER 2025 z x w S PROJECT: Plan Scale:1"=30' SHHEET25-129 ET N0. 1 OF 1 w a a SHEET NOTES A. SEE SHEET C1.1 FOR GENERAL,ACED,AND UTILITY �SSKOIIAL f*o NOTES. NSFq 4' f B. SEE SHEET C4.1 FOR RM TER S. v rew��y rew rew rew rew rew rewo Rw Rw aw=aw Rw Rw aw Rw Rw rew rew rew rew aw rew rew C. GROUNDWATER ELEVATIONOS AREAEXPECTEDLTO REMAIN O a rew� o p° ATOR DWATE 10TFEET FROM RE EXPECTED GROUND SURFACE. 9'Aj9rV Op�.� Q �IIIy 10"s 1c-s t0-s 1o^s N 1o"s 1o"s 1o'S 1o"s-. 1o"s 1o"s 1o"s 1o"s 1o"s t�"s to"s to's to"s tos tos tos tas tos tas tos tos THE DESIGN PITNLOGSA W�CH SHOW POORLHRGRADED ON F BASED `C OF �r-1o's 1p S GRAVEL AT THE APPROXIMATE BOTTOM DEPTH OF THE y�//y C• 6"SD 3s-SD 36"SDI 3s-s0 3s-s0 to s PROPOSED SEEPAGE BEDS.FOR ADDITIONAL INFORMATION 36"s036"s0 -36's0� REFER TO THE GEOTECHNICAL ENGINEERING REPORT N.TEN MILE RD. 'PROPOSED MIXED-USE DEVELOPMENT 2154 WEST FRANKLIN ROAD MERIDIAN,ID"PREPARED BY MTI,DATED 12'w 12-w 12 12w� 12w lzzv t 1 21 tz'w�:,2'w 121 tz'w 12'w z'w 12'w 1z'w 1s1INLET#7 -tzw 1z 121 1zw 1zw 12w 1zw 12w 1zw 1zw zw 1 12-w�1 MARCH 6,2020. INLETS#6A&6B 5 14.0' 12"ADS N-12 HE ztE ACHD SD-601,TYPE I 1­12'­12�­12�� ACHD SD-601,NPE 23.5' 12"C900 PVC RIM:2568.93®O'29% INLET 4 ®026% D. PROVIDE WATER-TIGHT SEALS AT PIPING RIM:2566.64 # - SUMP:2565.97 w ENTRANCES/EXITS FOR CATCH BASINS,DIVERSION BOXES, SUMP:2563.04 36"6D�36"SDI- ACHD SD-601,TYPE 36"3D D 36"BD 36"SD 36"80 36"80 36'80 36'80 36 s0 1�6INV OUT:2566.97 12"(W)-t2SD 1250�2.50 1250 1250 12"SD lz"SD 12-SD 12"80 1 AND MANHOLES. INV OUT:2564.04 12".04 - RIM:2567.61 { SUMP:2564.44 INLET#3 4.8' 12"ADS N-12 HP E. ALL STORM PIPE WITHIN ROW SHALL BE C900 WHERE INV IN:2565.44 12"(N) ACHD SD-601,TYPE I 6 '° 0 1 04% INLET#2 COVER OVER PIPE IS LESS THAN 2 FEET.OUTSIDE OF INV OUT2565.44 12"(S) RIM:2567.61 c c c c c ACHD SD-601,TYPE ROW OR WHERE COVER IS GREATER THAN 2 FEET THE a •• • Q25=0.41cfs SUMP:2564.50 --- a RIM:2571.72 STORM PIPE SHALL BE ADS N-12 HP PIPE OR Q100=0.58cfs 0 12 () - SUMP:2567.61 APPROVED EQ USED WHEN, INV OUT S UAL.PLOWABLE FILL SHALL BE US N ----- --- --------- --- --� INV IN 256861 '^ 7.0' 12"ADS N-12 HP' Q25=0.41cfs 2 (N( ID z1 ID z1 LESS THAN 5-FEET OF SEPARATION BETWEEN Q100=0.58cfs 6'PI 6'PI PI SGT 1 INV OUT:2568.611 12" S) - STRUCTURES. ®0.29% fi"PI fi"PI 6"PI 6"PI �. a ------------------------------------- 6'PI-6•P1 9 Q25=0.49cfs -------- 6" f _ �6"P RIM:2572.21 W �i. ° Q100=0.68cfs F. ALL DRAINAGE STRUCTURES SHALL BE PER ISPWC ys,Pl \� - - ------ 1�s.P1_� RIM:2572,32 (E) _ STANDARDS AND THE ACHD SUPPLEMENTS TO THE ISPWC. W , --- 6'PI 6"P- --6 P- - - - - - --- ,6'_--- _ _ $pr= ------ --6'PI_ INV IN:2568.56 12"(N)_ - -fig- " STORM DRAIN STRUCTURES SHALL HAVE HS-25 TRAFFIC \ �s SDMH #1 INV OUT:2567.71 18"(E) 'INLET#1 RATED LIDS UNLESS OTHERWISE SPECIFIED. 48'0 SDMH FLAT TOP 3 INLET BAFFLE:2568:46 ACHD SD-601,TYPE G. THE CONTRACTOR SHALL COMPLY WITH ALL THE RIM:25fi8.27s OUTLET BAFFLE:2566.46 RIM:2571.86 SUMP2563.42 r v Q25=1.00cfs f ,SUMP:2567.75 REQUIREMENTS FORR STORM WATER DISCHARGE INCLUDES Z g, - Q100-1.39cfs 'INV OUT:2568.75 12' ASSOCIATED WITH CONSTRUCTION ACTIVITY.THIS INV IN:2565.42 12"(N) (S) IMPLEMENTING THE BMP'S RECOMMENDED IN THE SWPP (e)� m fs :.4 50.5' 18"ADS ®10.00% 34Q7 2�0.71 cfs PLAN PREPARED FOR THIS SITE, REGULAR SITE ; g IN OUT:2565.42 12" E 33.4' 12"ADS N-12 HP la INSPECTIONS, DOCUMENTATION OF MODIFICATIONS TO THE - �, SWPPP AND OTHER REQUIREMENTS AS SET FORTH IN ®0.24% "C900 PVC THE NPDES GENERAL PERMIT. SGT#2 W < O 0.41 ti H. ALL CHANGES REQUIRE APPROVAL BY THE DESIGN RIM:2569.38(W) N m 3 " ENGINEER AND ACED. RIM:2569.53(E) INV IN:2565.34 12"(W) U J I. THE CONTRACTOR SHALL PROVIDE AND INSTALL STORM INV OUT25fi4.49 18"(E) 9 BLOCK2 PROPOSED ACHD STORM�• N BLOCK 3 . BLOCK 1 DRAIN MONUMENTS TO IDENTIFY ALL STORM DRAIN INLET BAFFLE:2564.24 O DRAIN EASEMENT U 3 OUTLET BAFFLE2565.24 m i MANHOLES, SEDIMENT BOXES, DROP INLETS,AND OTHER O Q25=0.83cfsI 2 O L m r --- O1 PIPE JUNCTIONS OR TERMINUSES IN ACCORDANCE WITH Q100=1.16cfs _ Yt--- a _ SECTION 8018 OF THE ACHD DEVELOPMENT POLICY 73.5 m18"ADS N-12 HP - MANUAL AND ISPWC SD-623. 2 m 0..0., ew a f -® J. FOR UTILITY CROSSINGS AT SEEPAGE BED LOCATIONS, h ,s° ~.. THE CONTRACTOR SHALL CONFORM TO THE STANDARDS z L-- _---J SET BY THE CITY OF MERIDIAN AND SECTION 8200 OF I Ia THE ACHD STORMWATER GUIDELINES. 3 - 1`• K. THE STORM WATER DESIGN IS BASED ON SECTIONS 8000 AND 8200 OF THE 2017 ACHD POLICY MANUAL. PROPOSED ACHD STORM _-- DRAIN EASEMENT KEYNOTES Y # 0 F •°°•�I °.' ~ Ilan UTILITY MAIN MAIN CROSSING O MAINTAIN VERTICAL AND HORIZONTAL � SEEPAGE BED #1 AND #2 PLAN POTABLE OF MERIDIAN MAIN LINE TS. SEE ON PER CIS OF MERIDIAN REQUIREMENTS. SEE WATER Q NOTE 2 SHEET C1.1 FOR ADDITIONAL 0 30 60 90 INFORMATION. z Plan Scale:1"=30' UTILITY MAIN/SERVICE CROSSING N © MAINTAIN VERTICAL AND HORIZONTAL Q z POTABLE/NON-POTABLE MAIN/SERVICE OR Q SERVICE/SERVICE LINE SEPARATION PER CITY N J MERIDIAN REQUIREMENTS.SEE WATER NOTE 3 SHEET C1.1 FOR ADDITIONAL INFORMATION. > Lo- Z r J l 1. SB#1 (PUBLIC),SEE SEEPAGE BED DETAIL#1/SECTION z Q ]C A-A ON SHEET C4.1 (451 X 15'W X 7'D). ? W K 2. SB#2(PUBLIC),SEE SEEPAGE BED DETAIL#1/SECTION N Q w ILL ON SHEET C4.1 (68'L x 13'W x 3.75'D). > 0 3 3. INSTALL GROUND WATER OBSERVATION WELL PER ACED z z O z SD-627,SHEET C4.1. INSTALL WITHIN THE INFILTRATION W Q 1 BED 5' FROM THE END AND OUTSIDE OF BED A Q Z MINIMUM OF 50' FROM THE PERIMETER OF THE BED. d p a 4. CONNECT TO EXISTING 12"900 PVC.MATERIALS 73.37. O m CONTRACTOR SHALL VERIFY PIPE MATERIALS, LOCATION, W AND INVERT PRIOR TO CONSTRUCTION. CONTRACTOR T(; J W x NOTIFY ENGINEER OF ANY DISCREPANCIES. W W (D O co 5. CONNECT TO EXISTING MANHOLE INV IN:2564.00. L>LJ Q d F_ CATCH BASIN/SEDIMENT BOX 6. CONNECT TO EXISTING 12"C900 PVC. INV I11:2566.97. W Z Yn LJJ ACHD SD-606,TYPE A CONTRACTOR SHALL VERIFY PIPE MATERIALS, LOCATION, RIM:2578.22 (W) AND INVERT PRIOR TO CONSTRUCTION. CONTRACTOR T(; 0 GRATE2577.79 (E) 6.5' 12"C900 PVC I NOTIFY ENGINEER OF ANY DISCREPANCIES. z G INV I12574.95 12"(E) 0 0.41% / Q O ILL N INV OUT:2573.46 12"(S) INLET#5 INLET BAFFLE:2574.27 ACHD SD-601,TYPE I W N OUTLET BAFFLE:2574.85 RIM:2578.02 INVSUM OUT2574. I /^m \ N > I C7 v 6'PI- -- 6'PI 6"P 6"PI �b4 6'PI m 12"GI 12"GI 12" ; I 2'G 1 In 14'0I 1 G "GI�12 12 12"0 a Q '�•'-T 12"GI®� I��tz•cllrcllz cl1 m P 6 D (,¢�}�/ 10.7' 12"C900 PVC g -12'W12'W12'w 12Y1121v 12'W 12yy�t 0 0.84% o r 2' 2'w12'W 1 YI 12-W 12 is'w- t2'w12"w12'w z'w- V) " W.o FRANKLIN RD. 0 SD 18-SD �18"SD 18'SDiB"Sp 18"SD 18"SD 1B"50 18"S-SD 18"SD 1880 D 18'8D l8"SD-�D t jRtV SD1B"SD 8"5- 18"SDie-SDtB"50ie"SDto"SDt8"SDte SD lam grewRwrew-}-Rw RwRw rewRw Rw rewRw�rew ENGINEERING O N . i 5725 NORTH DISCOVERY WAY BOISE,208)o 83713 9-6,3 O C I PHONE(2081639-6939 k...gllp. n, z G DESIGN BY: LCK Y SEDIMENT BOX #1 PLAN - W. FRANKLIN RD. DRAWN BY AD � CHECKED BY: LCK Q C 0 30 60 90 DATE: DECEMBER 2025 z 9 "an'Cale:1"=30' PROJECT' zs 129 `s SHEET NO. J C4.0 s a LEGEND h5T 46. E�SS`OCENSFN074' $WELL COVER,8"DIA.WATERTIGHT GALVANIZED STEEL BOLT DOWN COVER AND CANISTER f FINISH GRADE lJ 2 OR 3 BOLT LID WITH 9/16"HEAD AND SAE THREADS,GASKETED x (2)CONCRETE(COLLAR),CLASS 3000(ISPWC SECTION 703) 6860 Q 3/8"DIA HOLES OR SLOTS CUT INTO PIPE AT 3"ON CENTER a 12�7125 0 TRACER WIRE SHALL BE PLACED ON OUTSIDE OF PVC PIPE, MINIMUM 18 GAUGE, INSULATED,SINGLE- -- T @� Q CONDUCTOR COPPER WIRE, INSULATION COLOR SHALL BE GREEN WITH THREE 6"DIAMETER COILS 9C'ylE OF Vpp(1� ©PIPE SHALL BE PERFORATED PVC,ASTM D-3035,SDR 35. WELLS BACKFILLED IN A PIT REQUIRE 6" y c� PIPE.DRILLED WELLS MAY USE 4"PIPE //v C.KEN dal -I ® Q NONWOVEN FILTER FABRIC AROUND OPENINGS AND BOTTOM,FABRIC OVER CHIPS/DRAIN ROCK POLYPROPYLENE FIBER REINFORCEMENT AT 1 1/2 LBS/CY O° BACK FILL MATERIAL TO MATCH STORAGE MEDIA FOR OBSERVATION WELLS LOCATED WITHIN A BMP FACILITY. J USE PIPE BEDDING CHIPS FOR OBSERVATION WELLS LOCATED OUTSIDE BMP FACILITIES 18"PERF PIPE oe : PLAN CONCRETE COLLAR NOTES: MID1.GROUNDWATER OBSERVATION WELLS ARE FOR MEASUREMENT OF GROUNDWATER LEVELS WITHIN OR NEAR STORM DRAINAGE FACILITIES N.T.S. PERFORATION SCHEDULE 2.THIS DETAIL IS FOR WELLS INSTALLED BY DRILLING OR BY EXCAVATED PITS L 3/8"PERFORATIONS IN VALLEY 3. LOCATION OF GROUNDWATER OBSERVATION WELLS SHALL BE APPROVED BY ACHD 4.OBSERVATION WELLS NOT ALLOWED IN CURB OR VALLEY GUTTER SECTION OF CORRUGATED PIPE. 5 EA ON 18". u, PLAN VIEW a N o a N.T.S. 18"� c - m 'Ili�� 1- - III II II; - +TEIIIrnnIT1I - III III 111.Twil E IIEIII II "- Tcuilil, SECTION CONCRETE COLLAR r ° 12" INTERCONNECT INLETS WITH 12"G900 PVC PIPE. MATCH INVERT OUTLET ELEVATION OF OUTLET PIPE FROM DOWNSTREAM CATCH BASIN. Z > N.T.S. F BAFFLE WALL Q ELEV B y FLO TBC w ELEV A _ ELEV D TYPE INLET CATCH BASINS PER ACHE INLET BAFFLE WALL �II SUPPLEMENTAL DETAIL SO-601. MINIMUM ELEV C 20"ISTD 12"THICK CONCRETE BETWEEN INSIDE OF CATCH BASINS. DOUBLE INLET DETAIL SECTION A-A SCALE: TUTS N.T.S. NOTES 8 1.SAND AND GREASE TRAP USED FOR SUBSURFACE FACILITIES ONLY 0 LEGEND: SECTION (7 MANHOLE FRAME AND COVER PER SD-617(TYPICAL) N.T.S. 8 LOCATION AND FL ELEV.PER DESIGN PLANS(TYPICAL) H 1-FT USE GRADE RINGS(TYPICAL) 1-FT<H<=2-FT USE 24"DIA RCP RISER 2-FT<H<= 10-FT USE MANHOLE CONE&48"DIA RISERS Qe EL.A>EL.B BY 0.10'MIN EE D<EE B BY 0.10'MIN EL,1:<EL,B BY 0.50'MIN,UNLESS OTHERWISE APPROVED BY ACED WATERTIGHT SEAL 2017 ACED REVISION ¢ PRECAST BOX MANUFACTURER SHALL MARK FLOW DIRECTION AND LABEL INLET OR OUTLET 2017 ACHD REVISION ON SIDE OF BOX IDAHO STANDARDS FOR PUBLIC WORKS GROUNDWATER STANDARD DRAWING IDAHO STANDARDS STANDARD DRAWING SAND AND GREASE TRAP CONSTRUCT ON OBSERVATION WELL SD-627 FOCONSB IC RUCWORKS GROUNDWATER ACHD STORMWATER DESIGN STANDARD DRAWING Q (ACHD SUPPLEMENT) 1 OF 2 OBSERVATION WELL SD-627 GUIDELINES BMP 01 (ACHD SUPPLEMENT) 2 QF 2 i OF z N z z O a N J \ d GROUND L WATER r OBSERVATION M z GROUND WATER WELL#2 m LLI OBSERVATION WELL#'A 5- D S I A B. NO TREES ARE ALLOWED WITHIN N O Lu MIN. 10'OF THE OUTSIDE PERIMETER \ OF THE SEEPAGE BED / Z z O v1 W Q SAND AND GREASE TRAP I S O SDI ____ >a ELEV. - "B" s n = CL _ w L----� o O 18 0 PERFORATED vwi r - 5 LF OF 18"0 ADS N-12 HE 3 L J W Lu ADS N-12 HP SOLID WALL PIPE ELEV. - "C" - LLJ �J•J TRANSITION 5'IN BED NON-PERFORhTED I� --A > W Q ITO PERFORATED PIPE LENGTH VARIES, SEE TABLE THIS SHEET s s W PLAN VIEW v >a - aw Q ELEV. _ "D,. .� Q 0 �" J O SAND AND GREASE TRAP PER N ACHD REQUIREMENTS.REFER TO WIDTH VARIES, SEE W ACHD DETAIL BMP 01. WATERTIGHT CONNECTION 18"0 PEOFORATEDADS FINISH GROUND MAX.HSGW TABLE THIS SHEET N ADDITIONAL INFORMATION PER PLAN. N-12 HE -OR ROCK (n 18"ADS CAP ELEVATION Q 4 KEY 0 1. ISPWC 801 OR ASTM C33 FILTER SAND. z 2. 3/4"-2"ANGULAR ROCK. O MINIMUM OF 20" 3. 18"0 PERFORATED PIPE.INSTALL PERFORATIONS PER ACHD STORMWATER DESIGNBAFFLE SPACING GUIDELINES DETAIL BMP 20 AND DETAIL ON THIS SHEET. 4. SUITABILITY OF SUBGRADE TO BE VERIFIED BY GEOTECHNICAL ENGINEER. 4"OF"CHIPS PIPE BEDDING 5. NON-WOVEN FABRIC SHALL BE PROPEX GEOTEX 401 OR APPROVED EQUAL U MEETING ACHD STORMWATER DESIGN GUIDELINES SECTION 8202.23.OVERLAP 18"0 SOLID WALL ADS N-12 HP MINIMUM OF 1-FF TOP AND SIDES ONLY. D (EXTEND 5'INTO SEEPAGE BED) 6FOR SEEPAGE BEDS IN THE PUBLIC RIGHT-OF-WAY A MINIMUM OF 1.0-FTGROUND WATER PER COVER FROM TOP OF BED TO PAVEMENT SUBGRADE.INSTALL WOVEN GEOTEXTILE FABRIC OVER TOP OFBEDWOVEN FABRIC SHALL BE PROPEX GEOTEX 401F OR DETAIL.EXTENINIMMELOW APPROVED EQUAL MEETING ACHD STORMWATER DESIGN GUIDELINES SECTION (n THE BOTTOM OF SAND LAYER 8202.23. PROFILE VIEW z GENERAL NOTES O /� C /� F� LJ A. GROUNDWATER ELEVATIONS ARE EXPECTED TO REMAIN AT OR BELOW 13 FEET FROM EXISTING GROUND SURFACE. PLAN AND PROFILE SECTION VIEW A-A. SEEPAGE BEDS WITHIN GRAVELTH SIAT THEILAPPROXIMATETION RATE BOTTOM DEPTHHR BASED THE PROPOSED PIT SEEP AGE BEDS.FOR ADDIPONAL INFORMATION PUBLIC ROW REFER TO THE GEOTECHNICAL ENGINEERING REPORT"POLLARD LANE REALIGNMENT-POLLARD LANE&CHINDEN O 4 BOULEVARD"PREPARED BY MT,DATED AUGUST 31,2016 AND GROUNDWATER DATA PREPARED BY NATURAL E.L B. e RESOURCE SOLUTIONS,LLC. E N G I IN E R I IN II ALL DRAINAGE STRUCTURES SHALL BE HS25 OR GREATER LOAD RATED. 5725 NORTH DISCOVERYWAY r C. ALL GEOTEXTILE SEAMS SHALL OVERLAP 1 FOOT MINIMUM. BOISE,IDAHO 83]13 O D. BED WIDTH SHALL REMAIN CONSTANT. E. IF ROCK IS ENCOUNTERED,CONTRACTOR MUST HAVE A PERCOLATION TEST PERFORMED BY A SOILS ENGINEER PHONE(208)639-6939 AFTER SEEPAGE BED IS FULLY EXCAVATED. (NOTE:AN ACHD INSPECTOR MUST BE PRESENT FOR THE TEST). IF k-gllp.- z SEEPAGE BED TABLE THE PERCOLATION IS LESS THAN SPECIFIED BY THE SOILS REPORT AND ENGINEER,CONTRACTOR MAY NEED TO BLAST OR BORE TO CREATE CONDUIT FOR DRAINAGE TO OCCUR OR RE-DESIGN THE SYSTEM TO ACHIEVE THE DESIGN BY: LCK i REQUIRED INFILTRATION. SEEPAGE BED SECTION BED LENGTH(FT) BED WIDTH BED DEPTH(FT) ELEVATION"A" ELEVATION"B" ELEVATION"C" ELEVATION"D" GROUND WATER EL DESIGN VOLUME(CF) DESIGN INFILTRATION F. STORAGE VOLUME DOESN'T INCLUDE SAND WINDOW. DRAWN BY: JAO z (FT) RATE(IN/HR) G. WATER SERVICES,SEWER SERVICES,AND PRESSURE IRRIGATION MAINS CROSSING SEEPAGE BEDS SHALL BE CHECKED BY: LCK Q INSTALLED PER ACHD RED U IREMENTS. SB#1 (PUBLIC) A-A 45 15 7 2572.30 2570.20 2567.71 2563.20 2560.1f 2.324 8.0 H. FOR UNDERGROUND INFILTRATION SYSTEMS,INSTALL ELECTRONIC MARKERS ON EACH CORNER OF THE FACILITY. DATE: DECEMBER2025 z THE CONTRACTOR SHALL COORDINATE WITH THE ACHD INSPECTION DEPARTMENT FOR PLACEMENT OF THE SB#2(PUBLIC) A 68 13 3.75 2569.66 2567.15 2564.49 2563.40 2560.4f 1,936 ITO MARKERS DURING CONSTRUCTION AND PRIOR TO BACKFILLING. PROJECT: 25-129 I. CONTRACTOR SHALL VERIFY INFILTRATION RATE AFTER THE FACILITY IS FULLY EXCAVATED WITH THE ACHD 5 INSPECTOR PRESENT SHEET NO. h CONTRACTOR SHALL NOTIFY THE ENGINEER IMMEDIATELY IF GROUNDWATER IS ENCOUNTERED WITHIN 3-FEET OF J SEEPAGE BED DETAIL#1 THE BOTTOM DESIGN ELEVATION FOR ANY INFILTRATION FACILITY AND/OR IF IT IS HIGHER THAN ANTICIPATED. CA"1 W NTS (F s d APPENDIX B - TABLES Table 1 - Peak Flow Rates and Runoff Volumes Post-Development Peak Flow Rates (cfs) Tc (min.) 25-yr 100-yr Basin Al 10.0 0.51 0.71 Basin A2 10.0 0.49 0.68 Basin Al-A2 10.0 1.00 1.39 Basin B1 10.0 0.41 0.58 Basin B2 10.0 0.41 0.58 Basin B1 - B2 10.0 0.83 1.16 Post-Development Runoff Volumes Volume (cf) Required Basins Al -A2, SB#1 2,324 Basins B1- B2, SB#2 1,936 APPENDIX C - CALCULATIONS POST-DEVELOPMENT 25-YEAR CALCULATIONS ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Steps for Peak Discharge Rate using the Ratio�Mated for post-developme Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Gasser Land Development Subdivision No.1-Basin Al 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 25 4 Enter number of storage facilities(25 max) 6 Click to Show More Subbasins C Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 12,297 2,665 Acres 0.34 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avgl 0.80 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate 10 Min. Estimated Runoff Coefficients for Various Surface min - Type of Surface Runoff Coefficients"( 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Business Downtown areas 0.70-0.95 9 Calculate the Post-Development peak discharge(QPeak) QpeA 0.51 cfs Urban neighborhoods 0.50-0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(for sizing primary storage) V 681 ft3 Multi-family 0.60-0.75 V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0.40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Industrial and Commercial Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) err 592 W Heavy areas 0.90 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Parks,cemeteries 0. Playgrounds 0.20-0.0-0.35 5 Railroad yard areas 0.20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin Streets Asphalt 0.95 Basin Forebay V 68 ft' Concrete 0.95 Primary Treatment/StorageBasin V 613 ft' Brick 0.95 Subsurface Storage Roofs 0.95 Gravel 0.75 Volume Without Sediment Factor(See BMP 20 Tab) V 681 ft3 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 0. Average:2-6% 0.09 0.12 0.15 0. Steep:>6% 0.13 0.18 0.23 0. Adapted from ASCE P:\25-129\Civil\Calculations&Reports\Storm Drainage\Calcs\Basin A ACHD_SD_CALCS_112018.xism 12/7/2025,10:50 AM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. - Steps for Peak Discharge Rate using the Ratio�Mated for post-developme Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Gasser Land Development Subdivision No.1-Basin A2 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 25 Click to Show More Subbasins C Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 11,832 2,406 Acres 0.33 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted AvgJ 0.81 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate min 10 Min. Estimated Runoff Coefficients for Various Surface - Type of Surface Runoff Coefficients N 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 n/hr Business Downtown areas 0.70-0.95 9 Calculate the Post-Development peak discharge(QPeak) Qpe.k 0.49 cfs Urban neighborhoods 0.50-0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(far sizing primary storage) V 655 ft3 Multi-family 0.60-0.75 V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Enter Percentile Storm 195th percentile=0.60 in 95th Industrial and commercial ( p ] 0.60 In Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 569 ft' Heavy areas o.90 Parks,Cemeteries 0.10-0.25 12 Detention:Approved Discharge Rate t0 Surface Waters(if applicable) cfs Playgrounds 0.20-0.35 Railroad yard areas 0.20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin Streets Asphalt 0.95 Basin Forebay V 65 ft' Concrete 0.95 Primary Treatment/StorageBasin V 589 fts Brick 0.95 Subsurface Storage Roofs 0.95 Gravel 0.75 Volume Without Sediment Factor(See BMP 20 Tab) V 655 fts Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 o.11 0. Average:2-6% 0.09 0.12 0.15 0. Steep:>6% 0.13 0.18 0.23 0. Adapted from ASCE P:\25-129\Civil\Calculations&Reports\Storm Drainage\Calcs\Basin A ACHD_SD_CALCS_112018.x1sm 12/7/2025,10:50 AM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. - Steps for Peak Discharge Rate using the Ratio�Mated for post-developme Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Gasser Land Development Subdivision No.1-Basins Al and A2 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 25 Click to Show More Subbasins C Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 24,129 5,071 Acres 0.67 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted AvgJ 0.80 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate min 10 Min. Estimated Runoff Coefficients for Various Surface - Type of Surface Runoff Coefficients N 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 n/hr Business Downtown areas 0.70-0.95 9 Calculate the Post-Development peak discharge(QPeak) Qpe.k 1.00 cfs Urban neighborhoods 0.50-0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(far sizing primary storage) V 1,336 ft3 Multi-family 0.60-0.75 V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Enter Percentile Storm 195th percentile=0.60 in 95th Industrial and commercial ( p ] 0.60 In Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) V,r 1,162 ft. Heavy areas o.90 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Parks,Cemeteries 0.10-0.25Playgrounds 0.20-0.35 Railroad yard areas 0.20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin Streets Asphalt 0.95 Basin Forebay V 134 ft' Concrete 0.95 Primary Treatment/StorageBasin V 1,202 fts Brick 0.95 Subsurface Storage Roofs 0.95 Gravel 0.75 Volume Without Sediment Factor(See BMP 20 Tab) V 1,336 fts Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 o.11 0. Average:2-6% 0.09 0.12 0.15 0. Steep:>6% 0.13 0.18 0.23 0. Adapted from ASCE P:\25-129\Civil\Calculations&Reports\Storm Drainage\Calcs\Basin A ACHD_SD_CALCS_112018.x1sm 12/7/2025,10:50 AM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Steps for Peak Discharge Rate using the Ratio�Mated for post-developme Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Gasser Land Development Subdivision No.1-Basin Bl 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 25 4 Enter number of storage facilities(25 max) 3 Click to Show More Subbasins C Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 10,004 2,430 Acres 0.29 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avgl 0.78 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate 10 Min. Estimated Runoff Coefficients for Various Surface min - Type of Surface Runoff Coefficients"( 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Business Downtown areas 0.70-0.95 9 Calculate the Post-Development peak discharge(QPeak) QpeA 0.41 cfs Urban neighborhoods 0.50-0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(for sizing primary storage) V 556 ft3 Multi-family 0.60-0.75 V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0.40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Industrial and Commercial Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) err 483 W Heavy areas 0.90 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Parks,cemeteries 0. Playgrounds 0.20-0.0-0.35 5 Railroad yard areas 0.20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin Streets Asphalt 0.95 Basin Forebay V 56 ft' Concrete 0.95 Primary Treatment/StorageBasin V 500 ft' Brick 0.95 Subsurface Storage Roofs 0.95 Gravel 0.75 Volume Without Sediment Factor(See BMP 20 Tab) V 556 ft3 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 0. Average:2-6% 0.09 0.12 0.15 0. Steep:>6% 0.13 0.18 0.23 0. Adapted from ASCE P:\25-129\Civil\Calculations&Reports\Storm Drainage\Calcs\Basin B ACHD_SD_CALCS_112018.xism 12/7/2025,10:52 AM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. - Steps for Peak Discharge Rate using the Ratio�Mated for post-developme Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Gasser Land Development Subdivision No.1-Basin B2 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 25 Click to Show More Subbasins C Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 10,030 2,429 Acres 0.29 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted AvgJ 0.78 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate min 10 Min. Estimated Runoff Coefficients for Various Surface - Type of Surface Runoff Coefficients N 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 n/hr Business Downtown areas 0.70-0.95 9 Calculate the Post-Development peak discharge(QPeak) Qpe.k 0.41 cfs Urban neighborhoods 0.50-0.70 Residential 10 Calculate total runoff vol V far sizing V 557 ft3 Single Family 0.35-0.50 ( )( g primary storage) Multi-family 0.60-0.75 V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Enter Percentile Storm 195th percentile=0.60 in 95th Industrial and commercial ( p ] 0.60 In Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 485 ft' Heavy areas o.90 Parks,Cemeteries 0.10-0.25 12 Detention:Approved Discharge Rate t0 Surface Waters(if applicable) cfs Playgrounds 0.20-0.35 Railroad yard areas 0.20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin Streets Asphalt 0.95 Basin Forebay V 56 ft' Concrete 0.95 Primary Treatment/StorageBasin V 501 fts Brick 0.95 Subsurface Storage Roofs 0.95 Gravel 0.75 Volume Without Sediment Factor(See BMP 20 Tab) V 557 fts Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 o.11 0. Average:2-6% 0.09 0.12 0.15 0. Steep:>6% 0.13 0.18 0.23 0. Adapted from ASCE P:\25-129\Civil\Calculations&Reports\Storm Drainage\Calcs\Basin B ACHD_SD_CALCS_112018.xism 12/7/2025,10:52 AM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. - Steps for Peak Discharge Rate using the Ratio�Mated for post-developme Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Gasser Land Development Subdivision No.1-Basins Bl and B2 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 25 Click to Show More Subbasins C Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 20,034 4,859 Acres 0.57 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted AvgJ 0.78 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate min 10 Min. Estimated Runoff Coefficients for Various Surface - Type of Surface Runoff Coefficients N 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 n/hr Business Downtown areas 0.70-0.95 9 Calculate the Post-Development peak discharge(QPeak) Qpe.k 0.83 cfs Urban neighborhoods 0.50-0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(far sizing primary storage) V 1,113 ft3 Multi-family 0.60-0.75 V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Enter Percentile Storm 195th percentile=0.60 in 95th Industrial and commercial ( p ] 0.60 In Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 968 ft' Heavy areas o.90 Parks,Cemeteries 0.10-0.25 12 Detention:Approved Discharge Rate t0 Surface Waters(if applicable) cfs Playgrounds 0.20-0.35 Railroad yard areas 0.20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin Streets Asphalt 0.95 Basin Forebay V 111 ft' Concrete 0.95 Primary Treatment/StorageBasin V 1,002 fts Brick 0.95 Subsurface Storage Roofs 0.95 Gravel 0.75 Volume Without Sediment Factor(See BMP 20 Tab) V 1,113 fts Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 0. Average:2-6% 0.09 0.12 0.15 0. Steep:>6% 0.13 0.18 0.23 0. Adapted from ASCE P:\25-129\Civil\Calculations&Reports\Storm Drainage\Calcs\Basin B ACHD_SD_CALCS_112018.xism 12/7/2025,10:53 AM Version 10.5,November 2018 POST-DEVELOPMENT 100-YEAR CALCULATIONS ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Steps for Peak Discharge Rate using the Ratio�Mated for post-developme Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Gasser Land Development Subdivision No.1-Basin Al 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100 4 Enter number of storage facilities(25 max) 6 Click to Show More Subbasins C Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 12,297 2,665 Acres 0.34 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avgl 0.80 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate 10 Min. Estimated Runoff Coefficients for Various Surface min - Type of Surface Runoff Coefficients"( 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Business Downtown areas 0.70-0.95 9 Calculate the Post-Development peak discharge(QPeak) Qpeak 0.71 cfs Urban neighborhoods 0.50-0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(for sizing primary storage) V 948 ft3 Multi-family 0.60-0.75 V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0.40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Industrial and Commercial Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) err 592 W Heavy areas 0.90 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Parks,cemeteries 0. Playgrounds 0.20-0.0-0.35 5 Railroad yard areas 0.20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin Streets Asphalt 0.95 Basin Forebay V 95 ft' Concrete 0.95 Primary Treatment/StorageBasin V 853 ft' Brick 0.95 Subsurface Storage Roofs 0.95 Gravel 0.75 Volume Without Sediment Factor(See BMP 20 Tab) V 948 ft' Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 0. Average:2-6% 0.09 0.12 0.15 0. Steep:>6% 0.13 0.18 0.23 0. Adapted from ASCE P:\25-129\Civil\Calculations&Reports\Storm Drainage\Calcs\Basin A ACHD_SD_CALCS_112018.x1sm 12/7/2025,10:48 AM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. - Steps for Peak Discharge Rate using the Ratio�Mated for post-developme Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Gasser Land Development Subdivision No.1-Basin A2 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100 Click to Show More Subbasins C Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 11,832 2,406 Acres 0.33 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted AvgJ 0.81 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User calculate min o Min. Estimated Runoff Coefficients for Various Surface - Type of Surface Runoff Coefficients N 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Business Downtown areas 0.70-0.95 9 Calculate the Post-Development peak discharge(QPeak) Qpe.k 0.68 cfs Urban neighborhoods 0.50-0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(far sizing primary storage) V 911 ft3 Multi-family 0.60-0.75 V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Enter Percentile Storm 195th percentile=0.60 in 95th Industrial and commercial ( p ] 0.60 In Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) V,r 569 ft' Heavy areas o.90 Parks,Cemeteries 0.10-0.25 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0.20-0.35 Railroad yard areas 0.20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin Streets Asphalt 0.95 Basin Forebay V 91 ft' Concrete 0.95 Primary Treatment/StorageBasin V 820 ft' Brick 0.95 Subsurface Storage Roofs 0.95 Gravel 0.75 Volume Without Sediment Factor(See BMP 20 Tab) V 911 ft' Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 o.11 0. Average:2-6% 0.09 0.12 0.15 0. Steep:>6% 0.13 0.18 0.23 0. Adapted from ASCE P:\25-129\Civil\Calculations&Reports\Storm Drainage\Calcs\Basin A ACHD_SD_CALCS_112018.x1sm 12/7/2025,10:49 AM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. �W for Peak Discharge Rate using the Ratio�Mated for post-developme Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Gasser Land Development Subdivision No.1-Basins Al and A2 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100 Click to Show More Subbasins C Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 24,129 5,071 Acres 0.67 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted AvgJ 0.80 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate min 10 Min. Estimated Runoff Coefficients for Various Surface - Type of Surface Runoff Coefficients N 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc in/hr Business Downtown areas 0.70-0.95 9 Calculate the Post-Development peak discharge(QPeak) Qpeak 1.39 cfs Urban neighborhoods 0.50-0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(far sizing primary storage) V 1,859 ft3 Multi-family 0.60-0.75 V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Enter Percentile Storm 195th percentile=0.60 in 95th Industrial and commercial ( p ] 0.60 In Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) V,r 1,162 ft' Heavy areas o.90 Parks,Cemeteries 0.10-0.25 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0.20-0.35 Railroad yard areas 0.20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin Streets Asphalt 0.95 Basin Forebay V 186 ft' Concrete 0.95 Primary Treatment/StorageBasin V 1,673 ft' Brick 0.95 Subsurface Storage Roofs 0.95 Gravel 0.75 Volume Without Sediment Factor(See BMP 20 Tab) V 1,859 ft' Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 o.11 0. Average:2-6% 0.09 0.12 0.15 0. Steep:>6% 0.13 0.18 0.23 0. Adapted from ASCE P:\25-129\Civil\Calculations&Reports\Storm Drainage\Calcs\Basin A ACHD_SD_CALCS_112018.x1sm 12/7/2025,10:49 AM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Steps for Peak Discharge Rate using the Rational M�1171ated for post-developme Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Gasser Land Development Subdivision No.1-Basin Bl 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100 4 Enter number of storage facilities(25 max) 3 Click to Show More Subbasins C Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 10,004 2,430 Acres 0.29 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avgl 0.78 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate 10 Min. Estimated Runoff Coefficients for Various Surface min - Type of Surface Runoff Coefficients"( 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Business Downtown areas 0.70-0.95 9 Calculate the Post-Development peak discharge(QPeak) Qpeak 0.58 cfs Urban neighborhoods 0.50-0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(for sizing primary storage) V 773 ft3 Multi-family 0.60-0.75 V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0.40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Industrial and Commercial Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) err 483 W Heavy areas 0.90 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Parks,cemeteries 0. Playgrounds 0.20-0.0-0.35 5 Railroad yard areas 0.20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin Streets Asphalt 0.95 Basin Forebay V 77 ft' Concrete 0.95 Primary Treatment/StorageBasin V 696 ft' Brick 0.95 Subsurface Storage Roofs 0.95 Gravel 0.75 Volume Without Sediment Factor(See BMP 20 Tab) V 773 ft3 Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 0. Average:2-6% 0.09 0.12 0.15 0. Steep:>6% 0.13 0.18 0.23 0. Adapted from ASCE P:\25-129\Civil\Calculations&Reports\Storm Drainage\Calcs\Basin B ACHD_SD_CALCS_112018.xism 12/7/2025,10:51 AM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. - Steps for Peak Discharge Rate using the Ratio�Mated for post-developme Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Gasser Land Development Subdivision No.1-Basin B2 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100 Click to Show More Subbasins C Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 10,030 2,429 Acres 0.29 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.10 C=[(C1xAl)+(C2xA2)+(CnxAn)]/A Weighted AvgJ 0.78 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User calculate min o Min. Estimated Runoff Coefficients for Various Surface - Type of Surface Runoff Coefficients N 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Business Downtown areas 0.70-0.95 9 Calculate the Post-Development peak discharge(QPeak) Qpe.k 0.58 cfs Urban neighborhoods 0.50-0.70 Residential 10 Calculate total runoff vol V for sizing V 775 ft3 Single Family 0.35-0.50 ( )( g primary storage) Multi-family 0.60-0.75 V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Enter Percentile Storm 195th percentile=0.60 in 95th Industrial and commercial ( p ] 0.60 In Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 485 ft' Heavy areas o.90 Parks,Cemeteries 0.10-0.25 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0.20-0.35 Railroad yard areas 0.20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin Streets Asphalt 0.95 Basin Forebay V 78 ft' Concrete 0.95 Primary Treatment/StorageBasin V 698 ft' Brick 0.95 Subsurface Storage Roofs 0.95 Gravel 0.75 Volume Without Sediment Factor(See BMP 20 Tab) V 775 ft' Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 o.11 0. Average:2-6% 0.09 0.12 0.15 0. Steep:>6% 0.13 0.18 0.23 0. Adapted from ASCE P:\25-129\Civil\Calculations&Reports\Storm Drainage\Calcs\Basin B ACHD_SD_CALCS_112018.xism 12/7/2025,10:52 AM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. - Steps for Peak Discharge Rate using the Ratio�Mated for post-developme Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Gasser Land Development Subdivision No.1-Basins Bl and B2 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100 Click to Show More Subbasins C Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 3 4 5 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 20,034 4,859 Acres 0.57 6 Determine the Weighted Runoff Coefficient(C) 0.95 0.10 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted AvgJ 0.78 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate min 10 Min. Estimated Runoff Coefficients for Various Surface - Type of Surface Runoff Coefficients N 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc in/hr Business Downtown areas 0.70-0.95 9 Calculate the Post-Development peak discharge(QPeak) Qpeak 2.26 cfs Urban neighborhoods 0.50-0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(far sizing primary storage) V 1,549 ft3 Multi-family 0.60-0.75 V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Enter Percentile Storm 195th percentile=0.60 in 95th Industrial and commercial ( p ] 0.60 In Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 968 ft' Heavy areas o.90 Parks,Cemeteries 0.10-0.25 12 Detention:Approved Discharge Rate t0 Surface Waters(if applicable) cfs Playgrounds 0.20-0.35 Railroad yard areas 0.20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin Streets Asphalt 0.95 Basin Forebay V 155 ft' Concrete 0.95 Primary Treatment/StorageBasin V 1,394 ft' Brick 0.95 Subsurface Storage Roofs 0.95 Gravel 0.75 Volume Without Sediment Factor(See BMP 20 Tab) V 1,549 ft' Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 0. Average:2-6% 0.09 0.12 0.15 0. Steep:>6% 0.13 0.18 0.23 0. Adapted from ASCE P:\25-129\Civil\Calculations&Reports\Storm Drainage\Calcs\Basin B ACHD_SD_CALCS_112018.xism 12/7/2025,10:52 AM Version 10.5,November 2018 INLET AND GUTTER CAPACITIES Hydraulic Analysis Report Project Data Project Title: 25-129 Gasser Land Development Sub No. 1 Designer: LCK Project Date: December 7, 2025 Project Units: U.S. Customary Units Notes: Curb and Gutter Analysis: Curb and Gutter Analysis - Al Notes: Gutter Input Parameters Longitudinal Slope of Road: 0.0040 ft/ft Cross-Slope of Pavement: 0.0200 ft/ft Depressed Gutter Geometry Cross-Slope of Gutter: 0.0420 ft/ft Manning's n: 0.0170 Gutter Width: 1.5000 ft Gutter Result Parameters Design Flow: 0.7100 cfs Gutter Result Parameters Width of Spread: 7.4305 ft Gutter Depression: 0.3960 in Area of Flow: 0.5769 ft^2 Eo (Gutter Flow to Total Flow): 0.5022 Gutter Depth at Curb: 2.1793 in Inlet Input Parameters Inlet Location: Inlet in Sag Percent Clogging: 0.0000 % Inlet Type: Grate Grate Type: 45 degree tilt-bar w/2-1/4 in Grate Width: 1.5000 ft Grate Length: 2.2700 ft Local Depression: 0.0000 in Inlet Result Parameters Perimeter: 5.2700 ft Effective Perimeter: 5.2700 ft Area: 1.1577 ft^2 Effective Area: 1.1577 ft^2 Depth at center of grate: 0.1263 ft Computed Width of Spread at Sag: 6.2421 ft Flow type:Weir Flow Efficiency: 1.0000 Curb and Gutter Analysis: Curb and Gutter Analysis - A2 Notes: Gutter Input Parameters Longitudinal Slope of Road: 0.0040 ft/ft Cross-Slope of Pavement: 0.0200 ft/ft Depressed Gutter Geometry Cross-Slope of Gutter: 0.0420 ft/ft Manning's n: 0.0170 Gutter Width: 1.5000 ft Gutter Result Parameters Design Flow: 0.6800 cfs Gutter Result Parameters Width of Spread: 7.3024 ft Gutter Depression: 0.3960 in Area of Flow: 0.5580 ft^2 Eo (Gutter Flow to Total Flow): 0.5097 Gutter Depth at Curb: 2.1486 in Inlet Input Parameters Inlet Location: Inlet in Sag Percent Clogging: 0.0000 % Inlet Type: Grate Grate Type: 45 degree tilt-bar w/2-1/4 in Grate Width: 1.5000 ft Grate Length: 2.2700 ft Local Depression: 0.0000 in Inlet Result Parameters Perimeter: 5.2700 ft Effective Perimeter: 5.2700 ft Area: 1.1577 ft^2 Effective Area: 1.15 77 ft^2 Depth at center of grate: 0.1228 ft Computed Width of Spread at Sag: 6.0629 ft Flow type:Weir Flow Efficiency: 1.0000 Curb and Gutter Analysis: Curb and Gutter Analysis - 131 Notes: Gutter Input Parameters Longitudinal Slope of Road: 0.0300 ft/ft Cross-Slope of Pavement: 0.0200 ft/ft Depressed Gutter Geometry Cross-Slope of Gutter: 0.0420 ft/ft Manning's n: 0.0170 Gutter Width: 1.5000 ft Gutter Result Parameters Design Flow: 0.5800 cfs Gutter Result Parameters Width of Spread: 4.4631 ft Gutter Depression: 0.3960 in Area of Flow: 0.2239 ft^2 Eo (Gutter Flow to Total Flow): 0.7380 Gutter Depth at Curb: 1.4672 in Inlet Input Parameters Inlet Location: Inlet on Grade Inlet Type: Grate Grate Type: 45 degree tilt-bar w/2-1/4 in Grate Width: 1.5000 ft Grate Length: 2.2700 ft Local Depression: 0.0000 in Inlet Result Parameters Intercepted Flow: 0.4488 cfs Bypass Flow: 0.1312 cfs Approach Velocity: 2.5899 ft/s Splash-over Velocity: 5.4346 ft/s Efficiency: 0.7738 Curb and Gutter Analysis: Curb and Gutter Analysis - B2 Notes: Gutter Input Parameters Longitudinal Slope of Road: 0.0300 ft/ft Cross-Slope of Pavement: 0.0200 ft/ft Depressed Gutter Geometry Cross-Slope of Gutter: 0.0420 ft/ft Manning's n: 0.0170 Gutter Width: 1.5000 ft Gutter Result Parameters Design Flow: 0.5800 cfs Gutter Result Parameters Width of Spread: 4.4631 ft Gutter Depression: 0.3960 in Area of Flow: 0.2239 ft^2 Eo (Gutter Flow to Total Flow): 0.7380 Gutter Depth at Curb: 1.4672 in Inlet Input Parameters Inlet Location: Inlet on Grade Inlet Type: Grate Grate Type: 45 degree tilt-bar w/2-1/4 in Grate Width: 1.5000 ft Grate Length: 2.2700 ft Local Depression: 0.0000 in Inlet Result Parameters Intercepted Flow: 0.4488 cfs Bypass Flow: 0.1312 cfs Approach Velocity: 2.5899 ft/s Splash-over Velocity: 5.4346 ft/s Efficiency: 0.7738 SEEPAGE BED CALCULATIONS ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Note this spreadsheet pulls information from the"Peak QV"tab Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Gasser Land Development Subdivision No.1 Basins Al and A2-Seepage Bed#1(SB#1) 2 Enter number of Seepage Beds(25 max) 1 3 Design Storm 100 4 Weighted Runoff Coefficient C 0.80 Link to: QV Qvz — 5 Area A(Acres) 0.67 acres [QV3� 6 Approved discharge rate(if applicable) 0.00 cfs Qv4 QV5 _ 7 Is Seepage Bed in Common Lot? No V 2,324 ft3 25%Sediment 8 Set Total Design Width of All Drain Rock W 15.0 ft 9 Set Total Design Depth of All Drain Rock D 7.0 ft Rock Only,Do Not Include Filter Sand Depth or Cover 10 Void Ratio of Drain Rock Voids 0.4 0.4 for 1.5"-2"drain rock and 3/4"Chips 11 Design Infiltration Rate(8 in/hr max) Perc 8.00 in/hr 12 Size of WQ Perf Pipe(Pert 180°) Dia pipe 18 in 13 Size of Overflow Perf Pipe(Perfs 360°),REQD if Q100>3.3 cfs in 14 Calculate Total Storage per Foot Spf 52.2 ft3/ft 15 Calculate Design Length L 45 ft Override Value Required for Chambers 16 Variable Infiltration Window L SWL 45 ft 17 Variable Infiltration Window W SWW 15.0 ft 18 Time to Drain 4.7 hours 90%volume in 48-hours minimum 19 Length of WQ&Overflow Perf Pipes 45 ft 20 Perf Pipe Checks.Qperf>=Qpeak; where Qperf=CdxAxV(2xgxH) Optional Storage Chambers Note:This assumes chambers are organized in a rectangular layout. 1-StormTech, 1 Type of Chambers SC740 2 Volume to Store V 0 ft3 3 Installed Chamber Width Cw 4.25 ft Installed Chamber Depth Cd 2.50 ft Installed Chamber Height Ch 7.12 ft 4 Chamber Void Factor 5 Chamber Storage Volume,Without Rock,Per Manuf 45.90 ft3/Unit 6 Chamber Storage Volume,With Rock,Per Manuf 74.90 ft3/Unit 7 Total Number of Units Required 0 ea 8 Area of Infiltration Aperc ft, 9 Volume Infiltration Vperc 0 ft3/hr 10 Time to Drain hours 90%volume in 48-hours minimum P:\25-129\Civil\Calculations&Reports\Storm Drainage\Calcs\Basin AACHD_SD_CALCS_112018.xlsm 12/7/2025,10:54 AM Version 10.5,November 2018 ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Note this spreadsheet pulls information from the"Peak QV"tab Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Gasser Land Development Subdivision No.1 Basins Bl and B2-Seepage Bed#2(SB#2) 2 Enter number of Seepage Beds(25 max) 1 3 Design Storm 100 4 Weighted Runoff Coefficient C 0.78 Linkto: QV QV2 — 5 Area A(Acres) 0.57 acres [QV3� 6 Approved discharge rate(if applicable) 0.00 cfs QVTR55 7 Is Seepage Bed in Common Lot? No V 1,936 ft3 25%Sediment 8 Set Total Design Width of All Drain Rock W 13.0 ft 9 Set Total Design Depth of All Drain Rock D 3.8 ft Rock Only,Do Not Include Filter Sand Depth or Cover 10 Void Ratio of Drain Rock Voids 0.4 0.4 for 1.5"-2"drain rock and 3/4"Chips 11 Design Infiltration Rate(8 in/hr max) Perc 8.00 in/hr 12 Size of WQ Perf Pipe(Pert 180°) Dia pipe 18 in 13 Size of Overflow Perf Pipe(Perfs 360°),REQD if Q100>3.3 cfs in 14 Calculate Total Storage per Foot Spf 28.3 ft3/ft 15 Calculate Design Length L 68 ft Override Value Required for Chambers 16 Variable Infiltration Window L SWL 68 ft 17 Variable Infiltration Window W SWW 13.0 ft 18 Time to Drain 2.9 hours 90%volume in 48-hours minimum 19 Length of WQ&Overflow Perf Pipes 68 ft 20 Perf Pipe Checks.Qperf>=Qpeak; where Qperf=CdxAxV(2xgxH) Optional Storage Chambers Note:This assumes chambers are organized in a rectangular layout. 1-StormTech, 1 Type of Chambers SC740 2 Volume to Store V 0 ft3 3 Installed Chamber Width Cw 4.25 ft Installed Chamber Depth Cd 2.50 ft Installed Chamber Height Ch 7.12 ft 4 Chamber Void Factor 5 Chamber Storage Volume,Without Rock,Per Manuf 45.90 ft3/Unit 6 Chamber Storage Volume,With Rock,Per Manuf 74.90 ft3/Unit 7 Total Number of Units Required 0 ea 8 Area of Infiltration Aperc ft, 9 Volume Infiltration Vperc 0 ft3/hr 10 Time to Drain hours 90%volume in 48-hours minimum P:\25-129\Civil\Calculations&Reports\Storm Drainage\Calcs\Basin B ACHD_SD_CALCS_112018.xlsm 12/7/2025,10:55 AM Version 10.5,November 2018 APPENDIX D - GEOTECHNICAL ENGINEERING REPORT & GROUNDWATER DATA GEOTECHNICAL ENGINEERING REPORT - PROPOSED MIXED USE DEVELOPMENT (MTI, 03/06/2020) MATERIALS ONTESTING 8 INSPECTION AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections GEOTECHNICAL ENGINEERING REPORT of Proposed Mixed-USE Development 2954 West Franklin Road Meridian, ID Prepared for: GFI - Meridian Investments, LLC 74 East 500 South, Suite 200 Bountiful, UT 84010 MTI File Number B2003059 2791 S Victory View Way• Boise, ID 83709• (208)376-4748• Fax(208)322-6515 www.mti-id.com•mti(cDmti-id.com MATERIALS 6 March 2020 TESTING & Page# 1 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections Mr. Trevor Gasser GFI—Meridian Investments,LLC 74 East 500 South, Suite 200 Bountiful, UT 84010 801-809-9731 Re: Geotechnical Engineering Report Proposed Mixed-Use Development 2954 West Franklin Road Meridian, ID Dear Mr. Gasser: In compliance with your instructions, MTI has conducted a soils exploration and foundation evaluation for the above referenced development. Fieldwork for this investigation was conducted on 26 February and 3 March 2020. 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 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, MTI can provide 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 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 & Inspection \ri AL O ENSF0�G/,y�` 18300 Jacob Schlador, P. 3-6-2020 Reviewed by: Elizabeth Brown, P.E. Geotechnical Engi ee s� �� Geotechnical Services Manager v 9�f 0 F P � qc�e SCH\- *4�4L P�o Reviewed by: Monica Saculles, P.E. Senior Geotechnical Engineer 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 www.mti-id.com•mti anmti-id.com Copyright© Materials — Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 2 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections TABLE OF CONTENTS INTRODUCTION...............................................................................................................................................................3 ProjectDescription.................................................................................................................................................3 Authorization..........................................................................................................................................................3 Purpose...................................................................................................................................................................3 Scopeof Investigation............................................................................................................................................4 SITEDESCRIPTION..........................................................................................................................................................4 SiteAccess..............................................................................................................................................................4 RegionalGeology...................................................................................................................................................4 GeneralSite Characteristics....................................................................................................................................4 Regional Site Climatology and Geochemistry........................................................................................................5 SEISMICSITE EVALUATION............................................................................................................................................5 GeoseismicSetting.................................................................................................................................................5 Seismic Design Parameter Values..........................................................................................................................5 SOILSEXPLORATION......................................................................................................................................................6 Exploration and Sampling Procedures....................................................................................................................6 LaboratoryTesting Program...................................................................................................................................7 Soiland Sediment Profile.......................................................................................................................................7 VolatileOrganic Scan.............................................................................................................................................8 SITEHYDROLOGY...........................................................................................................................................................8 Groundwater...........................................................................................................................................................8 SoilInfiltration Rates..............................................................................................................................................9 SLOPESAND SETBACKS..................................................................................................................................................9 FOUNDATION,SLAB,AND PAVEMENT DISCUSSION AND RECOMMENDATIONS.............................................................10 Foundation Design Recommendations.................................................................................................................10 FloorSlab-on-Grade.............................................................................................................................................11 Recommended Pavement Sections.......................................................................................................................12 FlexiblePavement Sections..................................................................................................................................12 PavementSubgrade Preparation...........................................................................................................................13 Common Pavement Section Construction Issues .................................................................................................13 CONSTRUCTIONCONSIDERATIONS...............................................................................................................................14 Earthwork.............................................................................................................................................................14 DryWeather.........................................................................................................................................................15 WetWeather.........................................................................................................................................................15 SoftSubgrade Soils..............................................................................................................................................15 FrozenSubgrade Soils..........................................................................................................................................16 StructuralFill........................................................................................................................................................16 Backfillof Walls...................................................................................................................................................17 Excavations...........................................................................................................................................................17 GroundwaterControl............................................................................................................................................18 GENERALCOMMENTS..................................................................................................................................................18 REFERENCES.................................................................................................................................................................19 APPENDICES.................................................................................................................................................................20 Warranty and Limiting Conditions.......................................................................................................................20 Plate1:Vicinity Map............................................................................................................................................22 Plate2: Site Map...................................................................................................................................................23 Geotechnical Investigation Test Pit Log...............................................................................................................24 Geotechnical General Notes.................................................................................................................................32 AASHTO Pavement Thickness Design Procedures.............................................................................................33 Important Information About This Geotechnical Engineering Report.................................................................35 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 www.mti-id.com•mti anmti-id.com Copyright© Materials — Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 3 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections INTRODUCTION This report presents results of a geotechnical investigation and analysis in support of data utilized in design of structures as defined in the 2015 International Building Code (IBC). Information in support of groundwater and stormwater 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 development from those enumerated in this report should be brought to the attention of the soils engineer to determine whether changes in the provided 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 in the southwestern portion of the City of Meridian,Ada County, ID,and occupies a portion of the W%2SW'/4 of Section 11, Township 3 North, Range 1 West, Boise Meridian. This project will consist of a mixed used development. The northern quarter of the site is to consist of multi-family residential structures and the rest of the site will be commercial/retail structures. The site to be developed is approximately 39 acres in size. Total settlements are limited to 1 inch. Loads of up to 4,000 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 perform this exploration and analysis was given in the form of a written authorization to proceed from Mr. Trevor Gasser of GFI—Meridian Investments, LLC to Monica Saculles of Materials Testing and Inspection(MTI), on 18 February 2020. Said authorization is subject to terms, conditions, and limitations described in the Professional Services Contract entered into between GFI — Meridian Investments, LLC and MTI. Our scope of services for the proposed development has been provided in our proposal dated 10 February 2020 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 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 www.mti-id.com•mti anmti-id.com Copyright© Materials — Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 4 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections Scope of Investigation 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. The scope of work did not include design recommendations specific to individual structures. SITE DESCRIPTION Site Access Access to the site may be gained via Interstate 84 to the Ten Mile Road exit. Proceed north on Ten Mile Road approximately 0.8 mile to its intersection with Franklin Road. The site occupies the northeastern corner of this intersection. Presently the site exists as an agricultural field. The location is depicted on site map plates included in the Appendix. Regional Geology The project site is located within the western Snake River Plain of southwestern Idaho and eastern Oregon. The plain is a northwest trending rift basin, about 45 miles wide and 200 miles long,that developed about 14 million years ago(Ma)and has since been occupied sporadically by large inland lakes. Geologic materials found within and along the plain's margins reflect volcanic and fluvial/lacustrine sedimentary processes that have led to an accumulation of approximately 1 to 2 km of interbedded volcanic and sedimentary deposits within the plain. Along the margins of the plain, streams that drained the highlands to the north and south provided coarse to fine-grained sediments eroded from granitic and volcanic rocks, respectively. About 2 million years ago the last of the lakes was drained and since that time fluvial erosion and deposition has dominated the evolution of the landscape. The project site is underlain by the "Gravel of Whitney Terrace" as mapped by Othberg and Stanford (1993). Sediments of the Whitney terrace consist of sandy pebble and cobble gravel. The Whitney terrace is the second terrace above modern Boise River floodplain, is thickest toward its eastern extent, and is mantled with 2-6 feet of loess. General Site Characteristics The site to be developed is approximately 39 acres in size. Currently,the site is primarily used as an agricultural field and is irrigated with wheel lines. Ten Mile Creek runs roughly southeast to northwest and bisects the southwest corner of the property. Adjacent properties to the west, east, and south consist of commercial developments. The Union Pacific Railroad borders the northern property line with a residential subdivision located on the on the north side of its easement. 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 www.mti-id.com•mti anmti-id.com Copyright© Materials — Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 5 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections Vegetation on the site consists primarily of agricultural crops throughout much of the site. Mature trees, shrubs, and grass are present along the creek banks and the portion of the property between Ten Mile Creek and the intersection of Ten Mile Road and Franklin Road. The site ranges from relatively flat and level to gently sloping terrain. Generally, the site consists of a northwest-southeast trending ridge that slopes gently downward to the southwest towards Ten Mile Creek and also drops in elevation to the northeast towards a natural low point/drainage. Additionally, slopes along Ten Mile Creek range from roughly 1.5 feet horizontal to I foot vertical (1.5:1) to 2:1. The creek is concrete lined with existing bridge abutments where Ten Mile Road and Franklin Road bisect the channel along the property lines. Regional drainage is north and west toward the Boise River. Stormwater drainage for the site is achieved by percolation through surficial soils. The site is situated so that it is unlikely that it will receive any stormwater drainage from off-site sources. Stormwater drainage collection and retention systems are not in place on the project site. However, Ten Mile Road and Franklin Road have an incorporated curb, gutter, and drop inlet stormwater system. Regional Site Climatology and Geochemistry According to the Western Regional Climate Center, the average precipitation for the 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 I I I'F. Winds are generally from the northwest or southeast with an annual average wind speed of approximately 9 miles per hour(mph) and 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 water, groundwater, and soils in the region typically have pH levels ranging from 7.2 to 8.2. SEISMIC SITE EVALUATION Geoseismic Setting Soils on site are classed as Site Class D in accordance with Chapter 20 of the American Society of Civil Engineers (ASCE)publication ASCE/SEI 7-10. Structures 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. Seismic Design Parameter Values The United States Geological Survey National Seismic Hazard Maps (2008), includes a peak ground acceleration map. The map for 2% probability of exceedance in 50 years in the Western United States in standard gravity(g) indicates that a peak ground acceleration of 0.178 is appropriate for the project site based on a Site Class D. 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 www.mti-id.com•mti anmti-id.com Copyright© Materials — Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 6 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections The following section provides an assessment of the earthquake-induced earthquake loads for the site based on the Risk-Targeted Maximum Considered Earthquake (MCER). The MCER spectral response acceleration for short periods, Sms, and at 1-second period, Smi, are adjusted for site class effects as required by the 2015 IBC. Design spectral response acceleration parameters as presented in the 2015 IBC are defined as a 5% damped design spectral response acceleration at short periods, SDs, and at I-second period, SDI. The USGS National Seismic Hazards Mapping Project includes a program that provides values for ground motion at a selected site based on the same data that were used to prepare the USGS ground motion maps. The maps were developed using attenuation relationships for soft rock sites; the source model, assumptions, and empirical relationships used in preparation of the maps are described in Petersen and others (1996). Seismic Desiiyn Values Seismic Design Parameter Design Value Site Class D "Stiff Soil" SS 0.288 Si 0.102 Fa 1.570 Fv 2.393 SMs 0.452 SMI 0.243 SDS 0.301 SDI 0.162 SOILS EXPLORATION 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 locations were selected by Trevor Gasser of GFI—Meridian Investments, LLC and provided to MTI in the form of a map. Test pit sites were located in the field by means of a Global Positioning System (GPS) device and are reportedly accurate to within ten feet. Upon completion of investigation, each test pit was backfilled with loose excavated 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 sealed 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 in the Appendix. MTI recommends that these logs not be used to estimate fill material quantities. 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 www.mti-id.com•mti anmti-id.com Copyright© Materials — Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 7 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections 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 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 Testing—ASTM D4318 and Grain Size Analysis—ASTM C117/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 Gravel of Whitney Terrace. At ground surface throughout the majority of the site were lean clay with sand soils and silty clay with sand soils; however, clayey gravel with sand fill materials were encountered at ground surface in test pit 8. Clayey gravel with sand fills were dark brown, dry to slightly moist, medium dense, and contained fine to coarse-grained sand and 4-inch-minus cobbles. Lean clays with sand and silty clays with sand were dark brown, dry to slightly moist, medium stiff to very stiff, and contained fine to medium-grained sand. Organic materials and disturbed materials, as a result of plowing activities, were measured to depths of roughly 1 foot. Underlying the surficial lean clays were silty sand sediments. Silty sands were light brown, tan, and gray, dry to moist, dense to very dense, and contained fine to coarse-grained sand and in some instances contained intermittent weak calcium carbonate cementation. In test pit 8, poorly graded gravels with varying amounts of silt,clay, and sand sediments were encountered beneath the surficial fill materials. These poorly graded gravels were light brown, gray, and red-brown, dry to moist, dense to very dense, and contained fine to coarse-grained sand and 14-inch-minus boulders. Underlying the silty sands in test pit 4 were sandy silt soils. Sandy silts were light brown, moist to saturated, stiff to very stiff, and contained fine to coarse-grained sand. Beneath the gravel sediments in test pit 8 were clayey sand with gravel sediments. Clayey sands were red-brown, moist to saturated, medium dense, and contained fine to coarse-grained sand. At depth throughout the majority of the site were poorly graded gravels and sands. Poorly graded gravels and sands were tan to gray, dry to saturated, medium dense to dense, and contained fine to coarse-grained sand,20-inch-minus boulders. In some instances,trace amounts of clay content were noted. During excavation, test pit sidewalls were generally stable. However, moisture contents will affect wall competency with saturated soils having a tendency to readily slough when under load and unsupported. 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 www.mti-id.com•mti anmti-id.com Copyright© Materials — Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 8 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections Volatile Organic Scan 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 of contamination. Groundwater encountered did not exhibit obvious signs of contamination. 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 encountered in test pits at depths ranging from 10.1 to 17.1 feet bgs. Soil moistures in the test pits were generally dry to moist within surficial soils. Within the deeper developed soils, soil moistures graded from dry to saturated as the water table was approached and penetrated. In the vicinity of the project site, groundwater levels are controlled in large part by agricultural, residential, and commercial irrigation activity and leakage from nearby Ten Mile Creek. Maximum groundwater elevations likely occur during the later portion of the irrigation season. MTI has previously performed 14 geotechnical investigations within 0.45 mile of the project site. Information from these investigations has been provided in the table below. Groundwater Data Approximate Distance Direction from Site Groundwater Depth from Site mile feet b s December 2004 0.40 West 7.7 to 15.1 April 2005 0.36 Northwest 7.4 to 9.5 May 2005 0.45 Northwest 7.2 to 10.2 February 2017 0.19 South Not Encountered to 16.5 March 2017 0.37 Southeast Not Encountered to 16.8 June 2017 0.17 South 12.5 to 15.5 June 2017 0.30 South 9.5 to 15.2 February 2018 0.35 West Not Encountered to 15.0 October 2018 0.10 South Not Encountered to 15.4 May 2019 0.10 North 11.4 to 11.7 June 2019 0.10 East 8.7 to 9.7 June 2019 0.22 Northwest 10.4 to 12.0 July 2019 0.10 West 7.3 to 10.5 July 2019 0.40 South 8.0 to 13.6 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 www.mti-id.com•mti anmti-id.com Copyright© Materials - Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 9 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections For construction purposes, groundwater depth can be assumed to remain greater than 6.0 feet bgs throughout the year. However, leakage from Ten Mile Creek may cause elevated groundwater levels near the vicinity of the creek. Since this is an estimated depth and seasonal groundwater levels fluctuate, actual levels should be confirmed by periodic groundwater data collected from piezometers installed in test pits 3, 4, 6, and 8. 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 soils generally offer little permeability, with typical hydraulic infiltration rates of less than 2 inches per hour. Sandy silt soils will commonly exhibit infiltration rates from 2 to 4 inches per hour and silty sand sediments usually display rates of 4 to 8 inches per hour; though calcium carbonate cementation may reduce these values to near zero. Clayey sand with gravel and poorly graded gravel with clay and sand sediments typically have infiltration rates ranging from 2 to 6 inches per hour. Poorly graded sand and gravel sediments typically exhibit infiltration values in excess of 12 inches per hour; however, the presence of groundwater and clay content will significantly reduce these estimated rates. Due to the variability of soil types encountered throughout the site, the presence of groundwater, and clay content noted in some of the gravel and sand sediments, MTI recommends that infiltration testing be performed once the infiltration facility locations have been determined. However, for preliminary design purposes, an estimated infiltration rate of 2 inches per hour can be assumed for silty sand sediments encountered at depths ranging from 1.0 to 3.7 feet bgs. SLOPES AND SETBACKS Slopes 2 feet horizontal to 1 foot vertical (2:1) to 1.5:1 were noted along the banks of Ten Mile Creek. For structures to be constructed near Ten Mile Creek, it is necessary to apply slope setback requirements as outlined in the IBC. No potential slope stability deficiencies were noted during the investigation. Soils onsite are not sufficiently stable to allow vertical cuts greater than 4 feet to stand for an extended period of time. Soils in the project vicinity are stable at a 2:1 gradient. However, soil types throughout the area are variable, and existing slopes will be dependent upon soil composition. Proposed cut-fill sections constructed from these soils should not be steeper than 2:1. Cut slopes in fine-grained soil are stable on a 1.5:1 slope with respect to mass movement and downslope creep. Fill slopes should be placed and compacted in a controlled manner as detailed in the Structural Fill section of this report. Fills to be constructed on existing slopes steeper than 20 percent(approximately 5:1) should be benched a minimum of 10 feet into competent native soils. 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 www.mti-id.com•mti anmti-id.com Copyright© Materials — Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 10 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections To ensure slope stability with respect to surficial movement and gullying, cohesive soils should be placed on the face of slopes. This will help limit downslope creep and aid in re-vegetation of slope surfaces. When slopes are steeper than 2:1, soils must be aggressively protected from erosion. More granular soils will require an even greater degree of protection. Setbacks from constructed slopes should adhere to provisions of Section 1808.7 of the 2015 IBC. Footing loads on soil masses adjacent to slopes must be set back in accordance with the provisions of the IBC. For buildings constructed above slopes steeper than 3:1, the horizontal setback distance from the face of slope to the face of an upslope footing must be no less than t/3 the vertical height of the total slope, however, need not exceed 40 feet. Benches or steps in the slope do not modify slope height. For buildings constructed below slopes steeper than 3:1, the horizontal setback distance from the toe of the slope to the face of a downslope structure must be no less than %2 the vertical height of the total slope, however, need not exceed 15 feet. Retaining walls can be constructed to alter the dimensional parameters of a slope. The top of the retaining wall constitutes the toe of the slope, and slope height is determined from the top of wall. Downslope setback requirements can be reduced to zero if the retaining wall reduces the upslope gradient to 3:1 or flatter. Because upslope setbacks are determined at footing elevation,top of slope setbacks can be managed through the footing depth. In some cases, it may be desirable to use a foundation based on tip bearing piles or caissons to achieve greater footing depths. FOUNDATION, SLAB,AND PAVEMENT DISCUSSION AND RECOMMENDATIONS Various foundation types have been considered for support of the proposed development. 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 development 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. Presently,there are an unknown number of structures proposed for the project site. The following recommendations are not specific to the individual structures, but rather should be viewed as guidelines for the subdivision—wide development. Foundation Design Recommendations Based on data obtained from the site and test results from various laboratory tests performed,MTI recommends the following guidelines for the net allowable soil bearing capacity: 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 www.mti-id.com•mti anmti-id.com Copyright© Materials — Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 11 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections Soil Bearing Capacity M —Footing Depth ASTM D1557 Net Allowable Sub grade Compaction Soil Bearing Capacity Footings must bear on competent, undisturbed, native silty sand sediments, poorly graded gravel with silt and sand sediments, or compacted Not Required for Native structural fill. Existing lean clay soils and fill Soil materials (if encountered) must be completely 2,500lbs/ft2 removed from below foundation elements.' Excavation depths ranging from roughly 1.0 to 3.7 95% for Structural Fill feet bgs should be anticipated to expose proper bearing soils.2 'It will be required for MTI personnel to verify the bearing soil suitability for each structure at the time of construction. 2Depending on the time of year construction takes place, the subgrade soils may be unstable because of high moisture contents. If unstable conditions are encountered,over-excavation and replacement with granular structural fill and/or use of geotextiles may be required. The following sliding frictional coefficient values should be used: 1) 0.35 for footings bearing on native silty sand sediments and 2) 0.45 for footings bearing on native poorly graded gravel with silt and sand and granular structural fill. A passive lateral earth pressure of 351 pounds per square foot per foot(psf/ft) should be used for silty sand sediments. For native poorly graded gravel with silt and sand sediments and compacted sandy gravel fill, a passive lateral earth pressure of 496 psf/ft should be used. Footings should be proportioned to meet either the stated soil bearing capacity or the 2015 IBC minimum requirements. Total settlement should be limited to approximately 1 inch, and differential settlement should be limited to approximately %2 inch. Objectionable soil types encountered at the bottom of footing excavations should be removed and replaced with structural fill. Excessively loose or soft areas that are encountered in the footings subgrade will require over-excavation and backfilling with structural fill. To minimize the effects of slight differential movement that may occur because of variations in the 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 Uncontrolled fill was encountered in in the southwestern corner of the site. MTI recommends that these fill materials be removed to a depth of at least 1'/2 feet below existing grade. If fill materials remain after excavation, the exposed subgrade must be compacted to at least 95 percent of the maximum dry density as determined by ASTM D1557. The excavated fill materials can be replaced in accordance with the Structural Fill section provided that all organic material and/or debris is completely removed. Once final grades have been determined, MTI is available to provide additional recommendations. 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 www.mti-id.com•mti anmti-id.com Copyright© Materials — Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 12 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections Plow zones with organic materials were encountered in portions of the site. MTI recommends that the organic materials be removed. If plow zones remain after organic materials have been removed, the exposed subgrade must be compacted to at least 95 percent of the maximum dry density as determined by ASTM D1557. MTI personnel must 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 the maximum dry density as determined by ASTM D1557. A free-draining granular mat should be provided below slabs-on-grade to provide drainage and a uniform and stable bearing surface. This should be a minimum 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 3/4-inch (Type 1) crushed aggregate. The granular mat should be compacted to no less than 95 percent of the maximum dry density as determined by ASTM D1557. 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 and should adhere to recommendations outlined in the ACI 302.1R and ASTM E1745 publications. Upon request, MTI can provide further consultation regarding installation. Recommended Pavement Sections MTI has made assumptions 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 4 has been assumed for near-surface lean clay 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 section. Flexible Pavement Sections The American Association of State Highway and Transportation Officials (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. 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 www.mti-id.com•mti anmti-id.com Copyright© Materials — Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 13 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections AASHTO Flexible Pavement S ecifications Pavement Section Component' Driveways and Parking Driveways and Parking Light Duty Heavy Duty Asphaltic Concrete 2.5 Inches 3.0 Inches Crushed Aggregate Base 4.0 Inches 4.0 Inches Structural Subbase 10.0 Inches 12.0 Inches Compacted Subgrade See Pavement Subgrade See Pavement Subgrade Preparation Section Preparation Section 'It will be required for MTI personnel to 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: Granular structural fill material complying with the requirements detailed in the Structural Fill section of this report except that the maximum material diameter is no more than 2/3 the component thickness. Gradation and suitability requirements shall be per ISPWC Section 801, Table 1. Pavement Subgrade Preparation Uncontrolled fill was encountered in the southwestern corner of the project site. MTI recommends that these fill materials be removed to a depth of at least I%2 feet below existing grade. If fill materials remain after excavation, the exposed subgrade must be compacted to at least 95 percent of the maximum dry density as determined by ASTM D698. The excavated fill materials can be replaced in accordance with the Structural Fill section provided that all organic material and/or debris is completely removed. Once final grades have been determined, MTI is available to provide additional recommendations. Plow zones with organic materials were encountered in portions of the site. MTI recommends that the organic materials be removed. If plow zones remain after organic materials have been removed, the exposed subgrade must be compacted to at least 95 percent of the maximum dry density as determined by ASTM D698. MTI personnel must be present during excavation to identify these materials. Common Pavement Section Construction Issues The subgrade upon which above pavement sections are to be constructed must be properly stripped, compacted (if indicated),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 anticipated that pavement areas will be subjected to moderate traffic. Subgrade clayey soils near and above optimum moisture contents may pump during compaction. Pumping or soft areas must be removed and replaced with structural fill. 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 www.mti-id.com•mti anmti-id.com Copyright© Materials — Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 14 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections Fill material and aggregates, as well as compacted native subgrade soils, 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 D1557 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, native silty sand sediments, poorly graded gravel with silt and sand sediments, 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. Agricultural crops, 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 to depths of I foot (minimum), and wasted or stockpiled for later use. However, in areas where trees are/were present, deeper excavation depths should be anticipated. 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 MTI personnel, 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. Recommendations 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. 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 www.mti-id.com•mti anmti-id.com Copyright© Materials — Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 15 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections Dry Weather 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 that are 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. • Soft areas can be over-excavated and replaced with granular structural fill. • 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%2 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 methods include use of geotextiles, lime, and cement stabilization. MTI is available to provide recommendations and guidelines at your request. 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 www.mti-id.com•mti anmti-id.com Copyright© Materials — Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 16 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections 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. The onsite, shallow clayey and silty soils are susceptible to frost heave during freezing temperatures. For exterior flatwork and other structural elements, adequate drainage away from subgrades is critical. Compaction and use of structural fill will also help to mitigate the potential for frost heave. Complete removal of frost susceptible soils for the full frost depth, followed by replacement with a non-frost susceptible structural fill, can also be used to mitigate the potential for frost heave. MTI is available to provide further guidance/assistance upon request. 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 3/4-inch) material and no more than 12 percent fines (passing No. 200 sieve). These fill materials should be placed in layers 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 footings 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. 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 www.mti-id.com•mti anmti-id.com Copyright© Materials — Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 17 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections The ASTM D 15 57 test method must be used for samples containing up to 40 percent oversize (greater than 3/4- 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 maximum density or "break over"point. The number of required passes should be used as the requirements 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. Backfill of Walls 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 11/2 feet horizontal to 1 foot vertical (11/2:1) 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 long-term conditions. During the 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,particularly after penetration of the water table. 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 soil 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. 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 www.mti-id.com•mti anmti-id.com Copyright© Materials — Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 18 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections Groundwater Control Groundwater was encountered during the investigation but is anticipated to be below the depth of most construction. Excavations below the water table will require a dewatering program. Dewatering will be required prior to placement of fill materials. Placement of concrete can be accomplished through water by the use of a treme. It may be possible to discharge dewatering effluent to remote portions of the site, to a sump, or to a pit. This will essentially recycle effluent, thus eliminating the need to enter into agreements with local drainage authorities. Should the scope of the proposed project change, MTI should be contacted to provide more detailed groundwater control measures. 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 and 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. GENERAL COMMENTS Based on the subsurface conditions encountered during this investigation and available information regarding the proposed development,the site is adequate for the planned construction. When plans and specifications are complete, and if significant changes are made in the character or location of the proposed structure,consultation with MTI must be arranged as supplementary recommendations may be required. Suitability of subgrade soils and compaction of structural fill materials must 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. 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 Copyri www.mti-id.com•mti anmti-id.com ght© Materials Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 19 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections REFERENCES American Association of State Highway and Transportation Officials(AASHTO) (1993). AASHTO Guide for Design of Pavement Structures 1993.Washington D.C.:AASHTO. American Concrete Institute(ACI)(2015).Guide for Concrete Floor and Slab Construction:ACI 302.1R.Farmington Hills,MI:ACI. American Society of Civil Engineers(ASCE)(2013). Minimum Design Loads for Buildings and Other Structures: ASCE/SEI 7-10. Reston,VA:ASCE. American Society for Testing and Materials(ASTM)(2017). Standard Test Method for Materials Finer than 75-µm(No. 200)Sieve in Mineral Aggregates by Washing:ASTM C117.West Conshohocken,PA:ASTM. American Society for Testing and Materials(ASTM)(2014).Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates: ASTM C136.West Conshohocken,PA: ASTM. American Society for Testing and Materials (ASTM) (2012). Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort:ASTM D698.West Conshohocken,PA:ASTM. American Society for Testing and Materials (ASTM) (2012). Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort:ASTM D1557.West Conshohocken,PA:ASTM. American Society for Testing and Materials (ASTM) (2014). Standard Test Methods for California Bearing Ratio: ASTM D1883. West Conshohocken,PA: ASTM. American Society for Testing and Materials (ASTM) (2017). Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System):ASTM D2487.West Conshohocken,PA:ASTM. American Society for Testing and Materials (ASTM) (2017). Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils: ASTM D4318.West Conshohocken,PA:ASTM. American Society for Testing and Materials (ASTM) (2011). Standard Specification for Plastic Water Vapor Retarders Used in Contact with Soil or Granular Fill Under Concrete Slabs:ASTM E1745.West Conshohocken,PA: ASTM. Desert Research Institute.Western Regional Climate Center. [Online]Available:<http://www.wrcc.dri.edu/>(2020). International Building Code Council(2015).International Building Code,2015.Country Club Hills,IL: Author. Local Highway Technical Assistance Council(LHTAC) (2017). Idaho Standards for Public Works Construction, 2017. Boise, ID: Author. Othberg,K. L. and Stanford,L. A.,Idaho Geologic Society(1993). Geologic Map of the Boise Valley and Adjoining Area,Western Snake River Plain,Idaho. (scale 1:100,000).Boise,ID:Joslyn and Morris. U.S. Department of Labor, Occupational Safety and Health Administration. CFR 29, Part 1926, Subpart P: Safety and Health Regulations for Construction,Excavations(1986). [Online]Available:<www.osha.gov>(2020). U.S. Geological Survey (2020). National Water Information System: Web Interface. [Online] Available: <http://waterdata.usgs.gov/nwis>(2020). U.S. Geological Survey. (2011). U.S. Seismic Design Maps: Web Interface. [Online] Available: <https:Hearthquake.usgs.gov/designmaps/us/application.php>(2020). 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 Copyri www.mti-id.com•mti anmti-id.com ght© Materials Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 20 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections APPENDICES 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 purposes 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("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 Recommendations are Limited and Subject 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 commencement of construction, such conditions may be identified that require corrective actions, and these required corrective actions may impact the project budget. Therefore, construction recommendations in this report should be considered preliminary, and MTI should be retained to observe actual subsurface conditions during earthwork construction activities to provide additional construction recommendations as needed. Since geotechnical reports are subject to misinterpretation, do not separate the soil logs from the report. Rather, provide a copy of, or authorize for their use, the complete report to other design professionals or contractors. Locations of exploratory sites referenced within this report should be considered approximate locations only. For more accurate locations, services of a professional land surveyor are recommended. 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 www.mti-id.com•mti anmti-id.com Copyright© Materials — Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 21 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections This report is also limited to information available at the time it was prepared. In the event additional 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 comments 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 environmental services are needed, MTI can provide, via a separate contract, those personnel who are trained to investigate and delineate soil and water contamination. 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 Copyri www.mti-id.com•mti anmti-id.com ght© Materials Testingg&Inspection r E a J O 6 U) Q V pp N J m z u N� G C6 W^ 40 y � ~ LL IL LU Ln LW ) K cL o W (n (6 f6 O N N F U O Cn M _E 'a N — w N m o Z W p • C6 d U oMo 5 O > Q 0 Z lJJ fl- O M a) O c a 22 J Q J d 04 cC M D o N m T� ISF p LU t L ua 1+ Nil AM ILIF�D O co I 0 1 O J � � F—ViAl V/ 'JO _ 2 Icy ` Ld- UJI ell' dtS 4 �.y 7 i n aof lit k •f L � LU W"V .. Cj 'Iriw _jh 4U Uj _. V . >LU LIJ f i m L5 i3 VA N LZ b { D N � N Lb Zco E ' O a N ONMD- > m Z u . C co W S y W t E o N d 77; a LL w _ _ eZ 0 a in � Y o W Z in K cn o Cl) Z 3 CD U) E 2 O C� E 8Q m c sw w � 0 AD E-o o o ood o � o Q Z Q o o� >OD m �; Z u J ¢ m Q d Q d �i d o c) D s N m I I I I I I I I I I I I I I I I I I I I � I I � I I � I I � I I � I I U IQI U- bl U ICI d IZI Z IYI O IZI Z I�I ICI I I I I I I I I I I I I I I I I Q I I I I C I I G I I I I I I II I I I I I I I I I I I d I I I I I I I I � I I I I I I / I I I I � I I __ _____ _ _____ ___ _ _ ___ _ __ _ __ _ 0`d02l31IWN31 ____ I I I I / I I I / I I MATERIALS 6 March 2020 TESTING & Page# 24 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-1 Date Advanced: 27 Feb 2020 Logged by: Nick Stevens, G.I.T. Excavated by: Struckman's Backhoe Service Location: See Site Map Plates Latitude: 43.60646 Longitude: -116.43309 Depth to Water Table: 10.1 Feet bgs Total Depth: 12.2 Feet bgs Depth Field Description and USCS Soil and Sample Sample Depth Lab Feet bgs) Sediment Classification Type Feet bgs) Qp Test ID Silty Clay with Sand(CL-ML):Dark brown, dry to slightly moist, stiff to very stiff, with 0.0-1.8 fine to medium-grained sand. GS 1.0-1.5 1.25-2.5 A --Plow zone and organics noted to 0.7 foot bgs. Silty Sand(SM): Light brown, dry to slightly 1.8-4.8 moist, dense to very dense, with fine to coarse-grained sand. Poorly Graded Gravel with Sand (GP): Tan 4.8-12.2 to gray, dry to saturated, dense, with fine to coarse-grained sand and 6-inch minus cobbles. Lab Test ID M LL Sieve Analysis % passing) % - - 1W#4 #10 #40 #100 #200 A 20.7 28 6 1 100 99 95 88 81.3 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 www.mti-id.com•mti anmti-id.com Copyright© Materials — Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 25 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-2 Date Advanced: 26 Feb 2020 Logged by: Nick Stevens, G.I.T. Excavated by: Struckman's Backhoe Service Location: See Site Map Plates Latitude: 43.60767 Longitude: -116.43176 Depth to Water Table: 17.1 Feet bgs Total Depth: 17.2 Feet bgs Depth Field Description and USCS Soil and Sample Sample Depth Lab Feet bgs) Sediment Classification Type Feet bgs) Qp Test ID Lean Clay with Sand (CL): Dark brown, dry 0.0-1.0 to slightly moist, stiff to very stiff, with fine to 1.5-2.0 medium-grained sand. --Plow zone and organics noted throughout. Silty Sand (SM): Light brown, slightly moist 1.0-7.1 to moist, very dense, with fine to coarse- GS 1.5-2.0 B rained. Poorly Graded Sand with Gravel(SP): Tan to gray, dry to saturated, medium dense, with 7.1-17.2 fine to coarse-grained sand and 4-inch minus cobbles. --Trace clay content noted throughout. Lab Test ID M Sieve Analysis % assin % #4 #10 #40 #100 #200 B 30.9 NP NP 100 97 73 51 39.6 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 www.mti-id.com•mti anmti-id.com Copyright© Materials — Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 26 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-3 Date Advanced: 26 Feb 2020 Logged by: Nick Stevens, G.I.T. Excavated by: Struckman's Backhoe Service Location: See Site Map Plates Latitude: 43.60886 Longitude: -116.43316 Depth to Water Table: 15.6 Feet bgs Total Depth: 16.3 Feet bgs Notes: Piezometer installed to 16.3 feet bgs. Depth Field Description and USCS Soil and Sample Sample Depth Lab Feet bgs) Sediment Classification Type Feet bgs) Qp Test ID Silty Clay with Sand(CL-ML): Dark brown, 0.0-1.2 dry to slightly moist, stiff, with fine to 1.25- medium-grained sand. 1.75 --Plow zone and organics noted throughout. Silty Sand (SM): Light brown, slightly moist to moist, very dense, with fine to coarse- 1.2-6.7 grained and trace fine gravel. --Intermittent weak calcium carbonate cementation noted from 4.1 to 6 7 eet bgs. Poorly Graded Sand with Gravel(SP): Tan to gray, dry to saturated, medium dense to 6.7-16.3 dense, with fine to coarse-grained sand and 5-inch minus cobbles. --Trace clay content noted throughout. 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 www.mti-id.com•mti anmti-id.com Copyright© Materials — Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 27 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-4 Date Advanced: 26 Feb 2020 Logged by: Nick Stevens, G.I.T. Excavated by: Struckman's Backhoe Service Location: See Site Map Plates Latitude: 43.60873 Longitude: -116.42976 Depth to Water Table: 12.3 Feet bgs Total Depth: 14.3 Feet bgs Notes: Piezometer installed to 14.3 feet bgs. Depth Field Description and USCS Soil and Sample Sample Depth Lab Feet bgs) Sediment Classification Type Feet bgs) Qp Test ID Lean Clay with Sand (CL): Dark brown, dry to slightly moist, very stiff, with fine to 2 _ 0.0-3.7 medium-grained sand. 2.75 5 --Plow zone and organics noted to 0.8 foot bgs. Silty Sand (SM): Tan to gray, dry to slightly moist, very dense, with fine to coarse-grained 3.7-9.0 sand. --Intermittent weak calcium carbonate cementation noted from 3.7 to 7.1. Sandy Silt (ML): Light brown, moist to 9.0-14.3 saturated, stiff to very stiff, with fine to coarse-grained sand. 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 www.mti-id.com•mti anmti-id.com Copyright© Materials — Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 28 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-5 Date Advanced: 26 Feb 2020 Logged by: Nick Stevens, G.I.T. Excavated by: Struckman's Backhoe Service Location: See Site Map Plates Latitude: 43.60689 Longitude: -116.42939 Depth to Water Table: 14.2 Feet bgs Total Depth: 15.1 Feet bgs Depth Field Description and USCS Soil and Sample Sample Depth Lab Feet bgs) Sediment Classification Type Feet bgs) Qp Test ID Lean Clay with Sand (CL): Dark brown, dry to slightly moist, medium stiff to stiff, with 0.0-2.1 fine to medium-grained sand. 1.0-1.75 --Plow zone and organics noted to 0.7 foot bgs. Silty Sand(SM): Light brown, dry to slightly moist, very dense, with fine to coarse-grained 2.1-5.9 sand. --Intermittent weak calcium carbonate cementation noted throughout. Poorly Graded Sand with Gravel(SP): Tan to 5.9-9.2 gray, dry to slightly moist, dense to very dense, with fine to coarse-grained sand and fine to coarse gravel. Poorly Graded Gravel with Sand (GP): Tan 9.2-15.1 to gray, slightly moist to saturated, dense to very dense, with fine to coarse-grained sand and 6-inch-minus cobbles. 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 www.mti-id.com•mti anmti-id.com Copyright© Materials — Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 29 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-6 Date Advanced: 26 Feb 2020 Logged by: Nick Stevens, G.I.T. Excavated by: Struckman's Backhoe Service Location: See Site Map Plates Latitude: 43.60574 Longitude: -116.42925 Depth to Water Table: Not Encountered Total Depth: 16.4 Feet bgs Notes: Piezometer installed to 16.4 feet bgs. Depth Field Description and USCS Soil and Sample Sample Depth Lab Feet bgs) Sediment Classification Type Feet bgs) Qp Test ID Lean Clay with Sand (CL): Dark brown, dry 0.0-1.1 to slightly moist, stiff to very stiff, with fine to 1.75- medium-grained sand. 2.25 --Plow zone and organics noted throughout. Silty Sand(SM): Light brown, dry to slightly moist, dense to very dense, with fine to 1.1-5.1 coarse-grained sand and trace fine gravel. --Intermittent weak calcium carbonate cementation noted from 3.8 to 5.1 eet bgs. Poorly Graded Sand with Gravel(SP): Tan to 5.1-8.8 gray' dry to slightly moist, medium dense to dense, with fine to coarse-grained sand and fine to coarse gravel. Poorly Graded Gravel with Sand (GP): Tan to gray, dry to slightly moist, medium dense 8.8-16.4 to dense, with fine to coarse-grained sand and 16-inch minus boulders. --Trace clay content noted throughout. 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 www.mti-id.com•mti anmti-id.com Copyright© Materials — Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 30 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-7 Date Advanced: 26 Feb 2020 Logged by: Nick Stevens, G.I.T. Excavated by: Struckman's Backhoe Service Location: See Site Map Plates Latitude: 43.60501 Longitude: -116.43164 Depth to Water Table: Not Encountered Total Depth: 15.2 Feet bgs Depth Field Description and USCS Soil and Sample Sample Depth Lab Feet b s Sediment Classification Type Feet b s Qp Test ID Lean Clay with Sand (CL): Dark brown, dry 0.0-0.9 to slightly moist, stiff to very stiff, with fine to 1.5-2.0 medium-grained sand. --Plow zone and organics noted throughout. Silty Sand(SM): Light brown, dry to slightly moist, very dense, with fine to coarse-grained 0.9-5.9 sand. --Intermittent weak calcium carbonate cementation noted from 3.6 to 5.9 eet b s. Poorly Graded Gravel with Sand (GP): Tan to gray, dry to slightly moist, dense to very 5.9-15.2 dense, with fine to coarse-grained sand and 20-inch minus boulders. --Trace silt content noted throughout. 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 www.mti-id.com•mti anmti-id.com Copyright© Materials — Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 31 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-8 Date Advanced: 3 Mar 2020 Logged by: Nick Stevens, G.I.T. Excavated by: Struckman's Backhoe Service Location: See Site Map Plates Latitude: 43.60519 Longitude: -116.43300 Depth to Water Table: 11.5 Feet bgs Total Depth: 13.0 Feet bgs Notes: Piezometer installed to a depth of 13.0 feet bgs. Depth Field Description and USCS Soil and Sample Sample Depth Lab Feet bgs) Sediment Classification Type Feet bgs) Qp Test ID Clayey Gravel with Sand Fill (GC-FILL): Dark brown, dry to slightly moist, medium 0.0-3.1 dense, with fine to coarse-grained sand and 4-inch minus cobbles. --Organic materials noted to 0.3 foot bgs. Poorly Graded Gravel with Silt and Sand 3.1-7.8 (GP-GM): Light brown to gray, dry to slightly moist, dense, with fine to coarse- rained sand and 14-inch minus boulders. Poorly Graded Gravel with Clay and Sand 7.8-9.5 (GP-GC):Red-brown, slightly moist to moist, dense to very dense, with fine to coarse- rained sand and 14-inch minus boulders. Clayey Sand with Gravel (SC): Red-brown, 9.5-13.0 moist to saturated, medium dense, with fine to coarse-grained sand. 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 www.mti-id.com•mti anmti-id.com Copyright© Materials — Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 32 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections GEOTECHNICAL GENERAL NOTES UNIFIED SOIL CLASSIFICATION SYSTEM Ma'or Divisions Symbol Soil Descriptions Gravel&Gravelly GW Well-graded gravels;gravel/sand mixtures with little or no fines Soils<50% GP Poorly-graded ravels;gravel/sand mixtures with little or no fines Coarse-Grained coarse fraction GM Silt gravels;poorly-graded ravel/sand/silt mixtures Soils<50% passes No.4 sieve GC Clayey gravels;poorly-graded gravel/sand/clay mixtures passes No.200 Sand&Sandy SW Well-graded sands;gravellysands with little or no fines sieve Soils>50% SP Poorly-graded sands;gravellysands with little or no fines coarse fraction SM Siltysands;poorly-graded sand/gravel/silt mixtures passes No.4 sieve Sc Clayey sands;poorly-graded sand/gravel/clay mixtures ML Inorganic silts; sandy,gravellyor clayeysilts Silts&Clays Lean clays; inorganic, gravelly, sandy, or silty, low to medium-plasticity Fine-Grained LL<50 CL clays Soils>50% passes No.200 OL Organic,low-plasticityclays and silts sieve Silts&Clays MH Inorganic,elastic silts;sandy,gravellyor clayeyelastic silts LL>50 CH Fat clays;high-plasticity,inorganic clays OH Organic,medium to high-plasticityclays and silts HighlyOrganic Soils PT Peat,humus,h dric soils with high organic content RELATIVE ENSITY AND CONSISTENCY OISTURECONTENT AND CEMENTATION CLASSIFICATION I.AqqlF CATION Coarse-Grained Soils SPT Blow Counts N Description Field Test VeryLoose: <4 Dry Absence of moisture,dusty,dryto touch Loose: 4-10 SlightlyMoist Damp,but not visible moisture Medium Dense: 10-30 Moist Visible moisture Dense: 30-50 Wet Visible free water VeryDense: >50 Saturated Soil is usuallybelow water table Fine-Grained Soils SPT Blow Counts N Description Field Test VerySoft: <2 Weak Crumbles or breaks with handling or slight Soft: 2-4 finger pressure Medium Stiff: 4-8 Moderate Crumbles or breaks with considerable finger Stiff. 8-15 pressure VeryStiff: 15-30 Strong Will not crumble or break with finger pressure Hard: >30 PARTICLE SIZE ACRONYM LIST Boulders: > 12 in. GS grab sample Cobbles: 12 to 3 in. LL Liquid Limit Gravel: 3 in.to 5 mm M moisture content Coarse-Grained Sand: 5 to 0.6 mm NP non-plastic Medium-Grained Sand: 0.6 to 0.2 mm PI PlasticityIndex Fine-Grained Sand: 0.2 to 0.075 mm Qp penetrometer value, unconfined compressive strength, Silts: 0.075 to 0.005 mm tsf Clays: <0.005 mm V vane value,ultimate shearingstrength,tsf 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 www.mti-id.com•mti anmti-id.com Copyright© Materials — Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 33 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections AASHTO PAVEMENT THICKNESS DESIGN PROCEDURES Pavement Section Design Location:Proposed Mixed-Use Development,light Duty Average Daily Traffic Count: 400 All Lanes&Both Directions Design Life: 20 Years Percent of Traffic in Design Lane: 50% Terminal SeAceabflity Index(Pt): 2.5 Level of Reliability: 95 Subgrade CBR Value: 4 Subgrade Mr: 6,000 Calculation of Design-18 kip ESALs Daily Growth Load Design Traffic Rate Factors ESALs Passenger Cars: 120 2.0% 0.0008 851 Buses: 0 2.0% 0.6806 0 Panel&Pickup Trucks: 78 2.0% 0.0122 8,439 2-Axle,6-Tire Trucks: 1 2.0% 0.1890 1,676 Emergency Vehicles: 1.0 2.0% 4.4800 39,731 Dump 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% 2.9760 0 Average Daily Traffic in Design Lane: 200 Total Design Life 18-kipESALs: 50,698 Actual Log(ESALs): 4.705 Trial SN: 2.46 Trial Log(ESALs): 4.707 Pavement Section Design SN: 2.61 Design Depth Structural Drainage Inches Coefficient Coefficient Asphaltic Concrete: 2.50 0.42 n/a Asphalt-Treated Base: 0.00 0.25 n/a Cement-Treated Base: 0.00 0.17 n/a Crushed Aggregate Base: 4.00 0.14 1.0 Subbase: 10.00 0.10 1.0 Special Aggregate Subgrade: 0.00 0.09 0.9 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 Copyri www.mti-id.com•mti anmti-id.com ght© Materials Testingg&Inspection MATERIALS 6 March 2020 TESTING & Page# 34 of 36 INSPECTION b2003O5g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑Geotechnical Engineering ❑Construction Materials Testing ❑Special Inspections AASHTO PAVEMENT THICKNESS DESIGN PROCEDURES Pavement Section Design Location:Proposed Mixed-Use Development,Heavy Duty Average Daily Traffic Count: 400 All Lanes&Both Directions Design Ufe: 20 Years Percent of Traffic in Design Lane: 5011. Terminal Seviceability Index(Pt): 2.5 Level of Reliability: 95 Subgrade CBR Value: 4 Subgrade Mr: 6,000 Calculation of Design-18 kipFSALs Daily Growth Load Design Traffic Rate Factors ESALs Passenger Cars: 105 2.0% 0.0008 745 Buses: 1 2.0% 0.6806 6,036 Panel&Pickup Trucks: 70 2.0% 0.0122 7,574 2-Axle,6-Tire Trucks: 20 2.0% 0.1890 33,523 Emergency Vehicles: 1.0 2.0% 4.4800 39,731 Dump Trucks: 1 2.0% 3.6300 32,193 Tractor Semi Trader Trucks: 1 2.0% 2.3719 21,035 Double Trailer Tracks 1 2.0% 2.3187 20,563 Heavy Tractor Trailer Combo Trucks: 0 2.0% 2.9760 0 Average Daily Traffic in Design Lane: 200 Total Design Life 18-kipESALs: 161,400 Actual Log(FSALs): 5.208 Trial SN: 2.98 Trial Log(FSALs): 5.208 Pavement Section Design SN: 3.02 Design Depth Structural Drainage Inches Coefficient Coefficient Asphaltic Concrete: 3.00 0.42 n/a Asphalt-Treated Base: 0.00 0.25 n/a Cement-Treated Base: 0.00 0.17 n/a Crushed Aggregate Base: 4.00 0.14 1.0 Subbase: 12.00 0.10 1.0 Special Aggregate Subgrade: 0.00 0.09 0.9 2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515 Copyri www.mti-id.com•mti anmti-id.com ght© Materials Testingg&Inspection Impoplant Infopmation ahoul Geolechnical-Engineeping SubWhile . . . . . . . . . . . . . .cost overruns, claims, and help. The Geoprofessional Business Association (GBA) will not likely meet the needs of a civil-works constructor or even a has prepared this advisory to help you —assumedly different civil engineer.Because each geotechnical-engineering study a client representative—interpret and apply this is unique,each geotechnical-engineering report is unique,prepared geotechnical-engineering report as effectively as solely for the client. possible. In that way, you can benefit from a lowered Likewise,geotechnical-engineering services are performed for a specific exposure to problems associated with subsurface project and purpose.For example,it is unlikely that a geotechnical- conditions at project sites and development of engineering study for a refrigerated warehouse will be the same as them that, for decades, have been a principal cause one prepared for a parking garage;and a few borings drilled during of construction delays, cost overruns, claims, a preliminary study to evaluate site feasibility will not be adequate to and disputes. If you have questions or want more develop geotechnical design recommendations for the project. information about any of the issues discussed herein, contact your GBA-member geotechnical engineer. Do not rely on this report if your geotechnical engineer prepared it: Active engagement in GBA exposes geotechnical • for a different client; engineers to a wide array of risk-confrontation • for a different project or purpose; techniques that can be of genuine benefit for • for a different site(that may or may not include all or a portion of everyone involved with a construction project. the original site);or before important events occurred at the site or adjacent to it; e.g.,man-made events like construction or environmental Understand the Geotechnical-Engineering Services remediation,or natural events like floods,droughts,earthquakes, Provided for this Report or groundwater fluctuations. Geotechnical-engineering services typically include the planning, collection,interpretation,and analysis of exploratory data from Note,too,the reliability of a geotechnical-engineering report can widely spaced borings and/or test pits.Field data are combined be affected by the passage of time,because of factors like changed with results from laboratory tests of soil and rock samples obtained subsurface conditions;new or modified codes,standards,or from field exploration(if applicable),observations made during site regulations;or new techniques or tools.If you are the least bit uncertain reconnaissance,and historical information to form one or more models about the continued reliability of this report,contact your geotechnical of the expected subsurface conditions beneath the site.Local geology engineer before applying the recommendations in it.A minor amount and alterations of the site surface and subsurface by previous and of additional testing or analysis after the passage of time-if any is proposed construction are also important considerations.Geotechnical required at all-could prevent major problems. engineers apply their engineering training,experience,and judgment to adapt the requirements of the prospective project to the subsurface Read this Report in Full model(s). Estimates are made of the subsurface conditions that Costly problems have occurred because those relying on a geotechnical- will likely be exposed during construction as well as the expected engineering report did not read the report in its entirety.Do not rely on performance of foundations and other structures being planned and/or an executive summary.Do not read selective elements only.Read and affected by construction activities. refer to the report in full. The culmination of these geotechnical-engineering services is typically a You Need to Inform Your Geotechnical Engineer geotechnical-engineering report providing the data obtained,a discussion About Change of the subsurface model(s),the engineering and geologic engineering Your geotechnical engineer considered unique,project-specific factors assessments and analyses made,and the recommendations developed when developing the scope of study behind this report and developing to satisfy the given requirements of the project.These reports maybe the confirmation-dependent recommendations the report conveys. titled investigations,explorations,studies,assessments,or evaluations. Typical changes that could erode the reliability of this report include Regardless of the title used,the geotechnical-engineering report is an those that affect: engineering interpretation of the subsurface conditions within the context . the site's size or shape; of the project and does not represent a close examination,systematic . the elevation,configuration,location,orientation, inquiry,or thorough investigation of all site and subsurface conditions. function or weight of the proposed structure and Geotechnical-Engineering Services are Performed the desired performance criteria; • the composition of the design team;or for Specific Purposes, Persons, and Projects, . project ownership. and At Specific Times Geotechnical engineers structure their services to meet the specific As a general rule,always inform your geotechnical engineer of project needs,goals,and risk management preferences of their clients.A or site changes-even minor ones-and request an assessment of their geotechnical-engineering study conducted for a given civil engineer impact.The geotechnical engineer who prepared this report cannot accept responsibility or liability for problems that arise because the geotechnical conspicuously that you've included the material for information purposes engineer was not informed about developments the engineer otherwise only.To avoid misunderstanding,you may also want to note that would have considered. "informational purposes"means constructors have no right to rely on the interpretations,opinions,conclusions,or recommendations in the Most Of the "Findings" Related in This Report report.Be certain that constructors know they may learn about specific Are Professional Opinions project requirements,including options selected from the report,only Before construction begins,geotechnical engineers explore a site's from the design drawings and specifications.Remind constructors subsurface using various sampling and testing procedures.Geotechnical that they may perform their own studies if they want to,and be sure to engineers can observe actual subsurface conditions only at those specific allow enough time to permit them to do so.Only then might you be in locations where sampling and testing is performed.The data derived from a position to give constructors the information available to you,while that sampling and testing were reviewed by your geotechnical engineer, requiring them to at least share some of the financial responsibilities who then applied professional judgement to form opinions about stemming from unanticipated conditions.Conducting prebid and subsurface conditions throughout the site.Actual sitewide-subsurface preconstruction conferences can also be valuable in this respect. conditions may differ-maybe significantly-from those indicated in this report.Confront that risk by retaining your geotechnical engineer Read Responsibility Provisions Closely to serve on the design team through project completion to obtain Some client representatives,design professionals,and constructors do informed guidance quickly,whenever needed. not realize that geotechnical engineering is far less exact than other engineering disciplines.This happens in part because soil and rock on This Report's Recommendations Are project sites are typically heterogeneous and not manufactured materials Confirmation-Dependent with well-defined engineering properties like steel and concrete.That The recommendations included in this report-including any options or lack of understanding has nurtured unrealistic expectations that have alternatives-are confirmation-dependent.In other words,they are not resulted in disappointments,delays,cost overruns,claims,and disputes. final,because the geotechnical engineer who developed them relied heavily To confront that risk,geotechnical engineers commonly include on judgement and opinion to do so.Your geotechnical engineer can finalize explanatory provisions in their reports.Sometimes labeled"limitations; the recommendations only after observing actual subsurface conditions many of these provisions indicate where geotechnical engineers' exposed during construction.If through observation your geotechnical responsibilities begin and end,to help others recognize their own engineer confirms that the conditions assumed to exist actually do exist, responsibilities and risks.Read these provisions closely.Ask questions. the recommendations can be relied upon,assuming no other changes have Your geotechnical engineer should respond fully and frankly. occurred.The geotechnical engineer who prepared this report cannot assume responsibility or liabilityfor confirmation-dependent recommendations ifyou Geoenvironmental Concerns Are Not Covered fail to retain that engineer to perform construction observation. The personnel,equipment,and techniques used to perform an environmental study-e.g.,a"phase-one"or"phase-two"environmental This Report Could Be Misinterpreted site assessment-differ significantly from those used to perform a Other design professionals'misinterpretation of geotechnical- geotechnical-engineering study.For that reason,a geotechnical-engineering engineering reports has resulted in costly problems.Confront that risk report does not usually provide environmental findings,conclusions,or by having your geotechnical engineer serve as a continuing member of recommendations;e.g.,about the likelihood of encountering underground the design team,to: storage tanks or regulated contaminants.Unanticipated subsurface • confer with other design-team members; environmental problems have led to project failures.If you have not • help develop specifications; obtained your own environmental information about the project site, • review pertinent elements of other design professionals'plans and ask your geotechnical consultant for a recommendation on how to find specifications;and environmental risk-management guidance. • be available whenever geotechnical-engineering guidance is needed. Obtain Professional Assistance to Deal with You should also confront the risk of constructors misinterpreting this Moisture Infiltration and Mold report.Do so by retaining your geotechnical engineer to participate in While your geotechnical engineer may have addressed groundwater, prebid and preconstruction conferences and to perform construction- water infiltration,or similar issues in this report,the engineer's phase observations. services were not designed,conducted,or intended to prevent migration of moisture-including water vapor-from the soil Give Constructors a Complete Report and Guidance through building slabs and walls and into the building interior,where Some owners and design professionals mistakenly believe they can shift it can cause mold growth and material-performance deficiencies. unanticipated-subsurface-conditions liability to constructors by limiting Accordingly,proper implementation of the geotechnical engineer's the information they provide for bid preparation.To help prevent recommendations will not of itself be sufficient to prevent the costly,contentious problems this practice has caused,include the moisture infiltration.Confront the risk of moisture infiltration by complete geotechnical-engineering report,along with any attachments including building-envelope or mold specialists on the design team. or appendices,with your contract documents,but be certain to note Geotechnical engineers are not building-envelope or mold specialists. GEOPROFESSIONAL BUSINESS &Hit ASSOCIATION Telephone:301/565-2733 e-mail:info@geoprofessional.org www.geoprofessional.org Copyright 2019 by Geoprofessional Business Association(GBA).Duplication,reproduction,or copying of this document,in whole or in part,by any means whatsoever,is strictly prohibited,except with GBAs specific written permission.Excerpting,quoting,or otherwise extracting wording from this document is permitted only with the express written permission of GBA,and only for purposes of scholarly research or book review.Only members of GBA may use this document or its wording as a complement to or as an element of a report of any kind. Any other firm,individual,or other entity that so uses this document without being a GBA member could be committing negligent or intentional(fraudulent)misrepresentation. GROUNDWATER MONITORING DATA TEST PIT MAP R TP - 3 TP -4 �X I I X •I I � I ' w+ X L� I a I x a x ui oo 0 m Rft a R/W 0 o TP- 6 J a N OGI \ll TP o z c 0 O H 0 O — x Q — W W W W W. Ikm w 0 H N N C W 3 N 0 Z E N G I N E E R I N G 5725 NORTH DISCOVERY WAY Fo X PHONE(08)639-6939 GATEWAY AT TEN MILE o kmengllp.com MERIDIAN IDAHO a � DATE: 8-1-25 > PROJECT: 25-129 SHEET: TEST PIT MAP 1 OF 1 a 00 co o 00 N -i L6 I� LO LO LO LO N N N N II II II II CD (D CD CD W W W W Q Q Q Q H H H O O O O I? L Q Q a Q a a TP-3 TP-4 TP-6 TP-8 4/30/2020 Depth from Top Dry Dry Dry Dry GW Elev NA NA NA NA 5/13/2020 Depth from Top 14.00 10.42 12.83 8.50 GW Elev 2558.84 2560.94 2562.17 2559.34 6/1/2020 Depth from Top 13.33 10.75 12.83 8.50 GW Elev 2559.51 2560.61 2562.17 2559.34 6/18/2020 Depth from Top 12.83 9.00 13.08 8.33 GW Elev 2560.01 2562.36 2561.92 2559.51 7/6/2020 Depth from Top 12.58 7.25 13.25 8.00 GW Elev 2560.26 2564.11 2561.75 2559.84 7/24/2020 Depth from Top 12.33 7.25 13.33 8.00 GW Elev 2560.51 2564.11 2561.67 2559.84 8/6/2020 Depth from Top 12.08 6.67 13.25 7.83 GW Elev 2560.76 2564.69 2561.75 2560.01 8/23/2020 Depth from Top 12.08 6.58 13.25 7.83 GW Elev 2560.76 2564.78 2561.75 2560.01 9/1/2020 Depth from Top 12.17 6.58 13.17 7.92 GW Elev 2560.67 2564.78 2561.83 2559.92 9/17/2020 Depth from Top 12.67 6.75 13.33 7.92 GW Elev 2560.17 2564.61 2561.67 2559.92 10/3/2020 Depth from Top 13.001 7.08 13.671 8.08 GW Elev 2559.841 2564.281 2561.331 2559.76