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HomeMy WebLinkAboutCC - Storm Drainage ReportProject No. 190121 Storm Drainage Report for ENTRATA FARMS SUBDIVISION- Phase 2 Prepared by: John Carpenter, P.E. September 17, 2019 \ptJAL E4,6, `dr,\ S TER 10 8 6 0 09/17/2019 0 CARPS-�� T -O ENGINEERS CONSULTING ENGINEERS, SURVEYORS AND PLANNERS 332 NORTH BROADMORE WAY NAMPA, IDAHO 83687 208-442-6300 • FAX 208-466-0944 Entrata Subdivision Phase 2 Drainage Calculations STORM DRAINAGE SUMMARY Entrata Subdivision Phase 2 is located west of the intersection of N. Ten Mile Road and W. Franklin Road in Meridian, ID, The Kennedy Lateral defines the east boundary of the property and historically provided irrigation water to this property. Phase 1 of the project has been previously designed and constructed. Phase 1 improvements will be substantially complete prior to construction of Phase 2. Historically, runoff from the Phase 2 project area is directed to the north end of the property, no historic discharge to the lateral is being proposed. Entrata Subdivision Phase 2 consists of 29 multi -family lots, multiple landscape areas, underground utilities, attached curb and gutter, and street paving. The multi -family buildings consist of a mix of 2 and 3 story individual units. Each building cluster will have roof drains connected to storm drainage pipe that conveys the storm water to storage facilities. This report details the storm drainage facilities to be constructed with the Phase 2 improvements. A portion of the drainage from Phase 2 will be directed to facilities designed and constructed with Phase 1. See the Phase 1 Storm Report for more information. PRIVATE DRAINAGE Drainage from the site will be routed to Swale E, located at the north end of the property. Landscape runoff will be collected through Nyloplast area drains. Services will be provided for roof drain tie into the pipes along the buildings. Standard catch basins will collect road runoff, which will be pretreated through sand and grease traps prior to the Swale. Swale E will have a total depth of 3.5' with 3:1 side slopes. The Swale will be fenced off due to the facility depth, as well as safety concerns from local police. GROUNDWATER The attached geotechnical investigation identifies several test pits that have been excavated to determine soil conditions as well as groundwater elevation. Groundwater was encountered throughout the site. Refer to the geotechnical report in the appendix for approximate groundwater elevations. Contractor shall contact the project engineer for observations if groundwater is encountered at an elevation inconsistent with the geotechnical report. DESIGN CRITERIA Rational method is used for calculating the peak runoff flows: Q = C * I * A Runoff coefficients based on land use from Ada County Highway District Standards. Percolation rate at 4 in/hr was estimated due to lack of percolation test at this area. At the time of construction project engineer will observe soil conditions for concurrence with design. Owner's geotechnical engineer will verify soils if conditions do not appear consistent with design L:\190121\40_Final Design\Stormwater\190121 Storm Drainage Report Phase 2.doc Entrata Subdivision Phase 2 Drainage Calculations APPENDICES • A - Vicinity Map • B - Drainage Basin Map • C - Calculations and Stage Storage • D - Soils Report • E - Ground Water Monitoring Sheet L:\190121\40_Final Design\Stormwater\190121 Storm Drainage Report Phase 2.doc Entrata Subdivision Phase 2 Drainage Calculations rAINkNiHOWAA, All L:\190121\40—Final Design\Stormwater\190121 Storm Drainage Report Phase 2.doc ENTRATA FARMS ME I IN ME ME 1 ♦i� �■ ■■ ■- :1111•••• •••�•�►: � .�♦♦i■■�■ .► ■1���1■�� 1111111111 VICINITY MAP SCALE: I"=1000' =co U) ct �W 4 .,w M� � o N O N J ui Entrata Subdivision Phase 2 Drainage Calculations L:\190121\40_Finai Design\Stormwater\190121 Storm Drainage Report Phase 2.doc LL U 0 a O LL C3 °o a w 3w a o EDa � uj 0 oa � r aZ LL m C H N Q O 01 n im 1 SUBBASIN 4 0.15 ACRES BASIN MAP ENTRATA FARMS PHASE 2 SUBBASIN 5 0.46 ACRES KEYNOTES: UBASIN E: 3.05 AC B C BASIN B & C: 2.99 AC TO EXISTING PHASE 1 E milk SUBBASIN 3 div` �� ■�I��1��1 0.32 ACRES :1 ��■■I■�I�■111 11 11011!■!w!ls RON— , ����':�:': I�01■IIEI�I �!ilIII1#IIf�I� 0.30 ACRES UP e• �� ■low MEN ilii I�I�'i■ 11 mill z.:. (4 60 0 60 120 Entrata Subdivision Phase 2 Drainage Calculations APPENDIX C L:\190121\40_Final Design\Stormwater\190121 Storm Drainage Report Phase 2.doc Runoff Coefficents Developed Areas Surface Runoff Coefficients Roofs 0.95 Pavement and Concrete 0.9 Gravel Surfaces 0.4 Vegetative Landscaped Area 0.2 Turf Grass 0.1 Typical Undeveloped Area 0.15 Area (SF) Area (AC) C-value Roofs 33700 0.77 0.95 Pavement and Concrete 49623 1.14 0.9 Vegetative Landscaped Area 49750 1.14 0.2 Overall Area 133073 3.05 Average C 0.65 Entrata Farms Subdivision No. 2 Note: Dimensions noted are per OldCastle Precast 1of1 Pipe Flow Check 50 -year Cumulative Tc Total Area (A)= Run-off Coeffecient (C)= Percolation Rate= Side Slope (S)= Free Board= 3.05 Acres 0.65 4 in/hr 3 :1 0 ft Flow Rate Pipe Size Name Pipe Name (min) Percolation Area (Ar)= Above Ground Storage Volume= 1000 SF 7350 CF Area (cfs) (in.) Table 1: Volume Calculations for Drainage Pond E hr) (acres) 100 -year Duration (min) Intensity (in/hr) Area ( acres) Flow Rate Historical Q- CIA Flow Rate (cfs) (cfs) pert Rate r in/ hr) Ol Perc Flow Rate (Q,) (cfs) Net Flow Rate (cfs) ( Runoff Volume (n) (COAvailable V Storage (cf) Req'd Time to Additional Percolate Storage (cf) (Tp)(hr) 10 2.58 3.05 5.13 0.00 4.00 0.09 5.04 3023 7350 -4327 9 15 2.18 3.05 4.34 0.00 4.00 0.09 4.24 3818 7350 -3532 11 30 1.51 3.05 3.00 0.00 4.00 0.09 2.91 5238 7350 -2112 16 60 0.96 3.05 1.91 0.00 4.00 0.09 1.82 6539 7350 -811 20 120 0.54 3.05 1.07 0.00 4.00 0.09 0.98 7065 7350-285 SGT -1 to 21 720 0.12 3.05 0.24 0.00 4.00 0.09 0.15 6309 7350 -1041 19 1440 0.08 3.05 1 0.16 0.00 4.00 0.09 0.07 5746 7350 -1604 17 Note: Dimensions noted are per OldCastle Precast 1of1 Pipe Flow Check 50 -year Cumulative Tc Area Flow Rate Pipe Size Name Pipe Name (min) intensity (acres) Area (cfs) (in.) hr) (acres) Subbasin 1 AD -16 to 10 _(In 2.20 1.56 1.56 2.23 12 CB -6 C86 CB- Subbasin 2 � 10 2.20 0.30 1.86 2.66 15 CB -7 to Subbasin 3 10 2.20 0.32 2.18 3.12 15 SGT1 Subbasin 4 SGT -1 to 10 2.20 0.15 2.33 3.34 15 Swale E C to Subbasin 5 10 2.20 0.46 0.46 0.66 12 S SGT2 Note: Dimensions noted are per OldCastle Precast 1of1 Entrata Farms Subdivision No. 2 -DIM "Coun to jr Elevation Contour Area (SF) Incremental Volume (Cf) Cumulative Volume (cf) 2,556.50 21556.60 2,556.70 1006 1055 1106 N/A 103 108 0 103 211 2,556.80 1158 113 324 2,556.90 1211 118 443 2,557.00 1266 124 567 2,557.10 1321 129 696 2,557.20 1377 135 831 2,557.30 1435 141 971 2,557.40 1494 146 1118 2,557.50 1554 152 1270 2,557.60 1615 158 1429 2,557.70 1678 165 1593 2,557.80 1741 171 1764 2,557.90 1806 177 1942 2,558.00 1871 184 2125 2,558.10 1938 190 2316 2,558.20 2006 197 2513 2,558.30 2076 204 2717 2,558.40 2146 211 2928 2,558.50 2218 218 3147 2,558.60 2290 225 3372 2,558.70 2364 233 3605 2,558.80 2439 240 3845 2,558.90 2516 248 4093 2,559.00 2593 255 4348 2,559.10 2671 263 4611 2,559.20 2751 271 4882 2,559.30 2832 279 5161 2,559.40 2914 287 5449 2,559.50 2997 296 5744 2,559.60 3081 304 6048 2,559.70 3167 312 6360 2,559.80 3253 321 6681 2,559.90 3341 330 7011 2,560.00 3430 339 7350 1of1 Discharge Capacity for 12" PVC at 0.2% Project Description 12.0 in Friction Method Manning Wetted Perimeter Formula Solve For Full Flow Top Width Capacity Critical Depth 7.4 in Input Data 100.0% Roughness Coefficient 0.010 Channel Slope 0.002 ft/ft Normal Depth 12.0 in Diameter 12.0 in Discharge 2.07 cfs Maximum Discharge 2.23 cfs Results 2.07 cfs Discharge 2.07 cfs Normal Depth 12.0 in Flow Area 0.8 ftz Wetted Perimeter 3.1 ft Hydraulic Radius 3.0 in Top Width 0.00 ft Critical Depth 7.4 in Percent Full 100.0% Critical Slope 0.004 ft/ft Velocity 2.64 ft/s Velocity Head 0.11 ft Specific Energy 1.11 ft Froude Number (N/A) Maximum Discharge 2.23 cfs Discharge Full 2.07 cfs Slope Full 0.002 ft/ft Flow Type Undefined GVF Input Data Downstream Depth 0.0 in Length 0.0 ft Number Of Steps 0 GVF Output Data Upstream Depth 0.0 in Profile Description N/A Profile Headloss 0.00 ft Average End Depth Over Rise 0.0% Normal Depth Over Rise 0.0% Downstream Velocity 0.00 ft/s Upstream Velocity 0.00 ft/s Normal Depth 12.0 in Critical Depth 7.4 in Channel Slope 0.002 ft/ft Critical Slope 0.004 ft/ft Bentley Systems, Inc. Haestad Methods Solution FlowMaster Untitledl.fm8 Center [10.02.00.01] 9/17/2019 27 Siemon Company Drive Suite 200 W Page 1 of 1 Watertown, CT 06795 USA +1-203-755-1666 Discharge Capacity for 15" PVC at 0.2% Project Description 15.0 in Friction Method Manning Formula Solve For Full Flow Hydraulic Radius Capacity Top Width 0.00 ft Input Data 9.4 in Roughness Coefficient 0.010 Channel Slope 0.002 ft/ft Normal Depth 15.0 in Diameter 15.0 in Discharge 3,76 cfs Froude Number (N/A) Results 4.04 cfs Discharge 3.76 cfs Normal Depth 15.0 in Flow Area 1.2 ftz Wetted Perimeter 3.9 ft Hydraulic Radius 3.8 in Top Width 0.00 ft Critical Depth 9.4 in Percent Full 100.0 % Critical Slope 0.004 ft/ft Velocity 3.06 ft/s Velocity Head 0.15 ft Specific Energy 1.40 ft Froude Number (N/A) Maximum Discharge 4.04 cfs Discharge Full 3.76 cfs Slope Full 0.002 ft/ft Flow Type Undefined GVF Input Data Downstream Depth 0.0 in Length 0.0 ft Number Of Steps 0 GVF Output Data Upstream Depth 0.0 in Profile Description N/A Profile Headloss 0.00 ft Average End Depth Over Rise 0.0% Normal Depth Over Rise 0.0% Downstream Velocity 0.00 ft/s Upstream Velocity 0.00 ft/s Normal Depth 15.0 in Critical Depth 9.4 in Channel Slope 0.002 ft/ft Critical Slope 0.004 ft/ft Bentley Systems, Inc. Haestad Methods Solution FlowMaster Untitled1.fm8 Center [10.02.00.01] 9/17/2019 27 Siemon Company Drive Suite 200 W Page 1 of 1 Watertown, CT 06795 USA +1-203-755-1666 0 Oldcestle Precast* GENERAL NOTES Delivering Reliability 1000 GAL SEDIMENT VAULT 6'-0" HEIGHT �\ 3 1 /2" W-10" TYP. 8'-10" 4'-3" ID 83 ID '19' 5'-6" ID J Y \ ' t 8-10 6" FLOOR ~ W-10" 1. VAULTS ARE DESIGNED TO MEET ASTM C-858 w/AASTHO HS -25 LOADING 2. OPENING MAY BE SIZED AND LOCATED AS REQUIRED 3. OPTIONAL ACCESSORIES MAY BE CAST IN AS REQUIRED 4. FOR OPTIONAL HARDWARE CHECK HARDWARE SECTION. 5. IT IS RECOMMENDED THAT BITUMIMOUS MASTIC BE USED AT ALL JOINTS TANDARD CONFIGURATION (2)- 24" DIA. HOLE THRU FOR MANHOLE ACCESS. \ INLET BAF LE OUT BAFFLE CAST IN VAULT Items Shown Are Subject To Change Without Notice Issue Date: March 2018 1 (6) - 18" x 24" KNOCKOUTS (2x) I EACH END (4x) 2 EACH SIDE ©2018 Oldcastle Precast, Inc. Mailing Address Phone: 208465-0176 16419 Ten Lane Fax: 2084687129 oldcas epreca com%plant/nampa Nampa, 10 83687 Email: oprlampa@oldcasUe.c Oldeastle Precast Delivering Reliability vnn rAL SEDIMENT VAULT 5 " DIA. HOLE THRU 1ANHOLE ACCESS. 6--1 LET SIDE 5" GENERAL NOTES 1. VAULTS ARE DESIGNED TO MEET ASTM C-858 w/AASTHO HS -25 LOADING 2. OPENING MAY BE SIZED AND LOCATED AS REQUIRED 3. OPTIONAL ACCESSORIES MAY BE CAST IN AS REQUIRED 4. FOR OPTIONAL HARDWARE CHECK HARDWARE SECTION. 5. IT IS RECOMMENDED THAT BITUMIMOUS MASTIC BE USED AT ALL JOINTS Items Shown Are Subject To Change Without Notice Issue Date: April 2018 Mailing Address Phone: 208465-0176 16419 Ten Lane Fax: 208465-7129 Nampa, ID 83687 Email: opnampa@oldcastle.com STANDARD CONFIGURATION OUTLET BAFFLE CAST IN VAULT (6) - 17" x 23" KNOCKOUTS (2x) I EACH END (4x) 2 EACH SIDE 1 @2018 Oldcaslle Precast, Inc. oldcastleprecast.com/plant/nampa Entrata Subdivision Phase 2 Drainage Calculations � " 1 1 L:\190121\40_Final Design\Stormwater\190121 Storm Drainage Report Phase 2.doc GeoTek, Inc. 320 East Corporate Drive Suite 300 Meridian, ID 83642-3511 (208) 888-7010 (208) 888-7924 ' www.geotekusa.com October 25, 2017 Project No. 1905-ID3 LAND DEVELOPMENT PARTNERS, LLC 4685 S. Highland Dr., Suite 202 Salt Lake City, Utah 84117 Attention: Mr. James Doolin Subject: Geotechnical Evaluation for "Franklin and Ten Mile" - a 17.7± Acre Multi -Family Residential Located West of N. Ten Mile Road and North of W. Franklin Road, Meridian, Idaho In accordance with your request, GeoTek, Inc. (GTI) has completed a geotechnical evaluation of the subject property for the construction of a multi -family residential development and associated improvements. The purpose of our study was to evaluate the soils underlying the site and to provide recommendations for project design and construction based on our findings. This report outlines the geotechnical conditions of the site based on current data, and provides earthwork and construction recommendations with respect to those conditions. SCOPE OF SERVICES The scope of our services has included the following: I . Review of soils and geologic reports and maps for the site (Appendix A). 2. Site reconnaissance. 3. Review of aerial photographs. 4. Excavating and logging of five (5) exploratory test pits (Appendix B). 5. Obtaining samples of representative soils, as the exploratory test pits were advanced. 6. Performing laboratory testing on representative soil samples (Appendix D). 7. Assessment of potential geologic constraints. 8. Engineering analysis regarding foundation design/construction, foundation settlement, and site preparation. 9. Preparation of this report. GEOTECHNICAL I ENVIRONMENTAL I MATERIALS FRANKLIN AND TEN MILE OCTOBER 2S, 2017 LAND DEVELOPMENT PARTNERS, LLC PAGE 2 PROJECT NO. 1905-ID3 SITE DESCRIPTION The project site consists of irregularly shaped parcels totaling approximately 17.7± acres that is generally bound by W. Franklin Road to the south, the Kennedy Lateral to the north and east, and undeveloped agricultural land to the west in the City of Meridian, Ada County, Idaho (Figure 2). Access to the Site is possible from W. Franklin Road. The property is mainly undeveloped agricultural land with a single family residence with improvements and animal corrals. A roadway exists on the Site allowing access to the animal corrals, which is located in the southern section of the property. Irrigation laterals exist along the eastern border and an irrigation lateral running east to west bisects the Site. From topographic maps, the site's elevation is approximately 2,555+ to 2,570+ feet above mean sea level. Natural drainage at the Site is interpreted to be downward to the south-southwest for the southern half of the Site, and to the north on the northern section of the Site, conforming to the natural topography in the area. Due to ongoing irrigation practices, standing water was observed on the Site on the date of our reconnaissance. PROPOSED DEVELOPMENT It is our understanding that site development would consist of performing typical cut and fill earthwork to attain the desired graded configurations) for the construction of multiple one to two- story residential structures. It is further assumed that final site grade will be within 3 feet of existing site grade. FIELD STUDIES Subsurface conditions at the site were explored by using a rubber -tired backhoe. Five (5) test pits were advanced onsite. A log of each exploration is included with this report in Appendix B. Two (2) percolation tests were also performed on the subject site (Appendix C). Two (2) ground water measurement standpipe piezometers were installed onsite. Field studies were completed during October of 2017 by our field personnel who conducted field excavation location mapping, logged the excavations, and obtained samples of representative soils for laboratory testing. The approximate locations of the explorations are indicated on the enclosed Site Exploration Plan (Figure 2). The Unified Soil Classification System (USCS) Classification was used to visually classify the onsite soils during the field evaluation. REGIONAL GEOLOGY The subject site is situated within the western portion of the Boise River Valley, which comprises the northwestern portion of the Snake River Plain physiographic province. The western portion of the Snake River Plain is aligned in a northwest -southeast direction and generally divides the Owyhee mountains to the south from the Central Idaho mountains toward the north (Wood and Clemens, 2004). The headwaters of the Boise River are located in the Central Idaho mountains east of Boise, Idaho. The river leaves the central mountains and enters the Snake River Plain near Barber and drains toward the west into the Snake River near Parma. The Owyhee mountains and the Central Idaho FRANKLIN AND TEN MILE LAND DEVELOPMENT PARTNERS, LLC PROJECT NO. 1905-11133 OCTOBER 25, 2017 PAGE 3 Mountains are composed predominantly of volcanic and igneous rocks. The western portion of the Snake River Plain is a northwest trending complex graben formed by extension and regional uplift along the northern boundary of the basin and range province (Wood and Clemens, 2004). The graben generally forms a basin which has been partially filled with younger sedimentary and volcanic rocks (Malde, 1991). The Boise River Valley is bounded on the northeast by the Boise Front, which is a northwest trending topographic high extending generally from Boise to Emmett, Idaho. The Boise Front consists of Cretaceous aged granitic and metamorphic rocks cut by Tertiary aged rhyolite and overlain with Miocene aged lake sediments (Wood and Clemens, 2004). These units have been cut by northwest trending faults which down drop these units toward the southwest. The faults also provide conduits for Quaternary aged basalt intrusions and flows (Malde, 1991). The depositional environment for the valley floor is dominantly lake laid deposits of sand, silt and clay. These materials were deposited during two periods of lake activity, one during the Miocene and the other during the Pleistocene. This valley infilling process has been subsequently truncated by down faulting within the valley ranging in height from a few feet to over 50 feet. Younger alluvium has been, and continues to be, transported dominantly by water and deposited on the basins gently sloping valley floor and within low-level flood plains. Portions of the alluvial deposits are being down cut by intermittent streams to the flood plain, and as a result stream terraces are being formed. SITE SOILS Artificial Fill Based on our field studies, some spread fills were observed along the perimeter of the site and near the interior roadway and agricultural structures. This fill is generally associated with the construction of the roadway and nearby residential developments. This spread fill shall be considered artificial fill. The majority of the property has been cultivated for agricultural use, the upper 12 inches of material has been disturbed and consists of a sandy silt with a moderate amount of organics and roots, this shall be considered artificial fill. Deeper fills may be encountered onsite. The "Artificial Fills" are soft and contain organics/roots and are not considered suitable for support of foundations. All artificial fill material should be removed as described in the "Removals" section of this report. Native Alluvial Soils Alluvial soils encountered generally consisted of surficial layers of sandy silt and silt underlain by poorly graded sand and silts with varying amounts of sand content. The moisture content within the alluvial materials was generally slightly moist to moist near surface and moist to saturated at depth. The consistency of these soils ranged from soft to firm near surface and medium dense to dense/stiff at depth. We anticipate that the onsite soils can be excavated with conventional earthwork equipment. Thin partially cemented lenses of soils were encountered in one of our excavations; however, we anticipate that the onsite soils can be excavated with conventional earthwork equipment equivalent to CAT D9R dozers and CAT 235 excavators. Special excavation equipment and techniques may be necessary dependent upon if harder materials are encountered during construction. FRANKLIN AND TEN MILE LAND DEVELOPMENT PARTNERS, LLC PROJECT NO. 1905-1133 OCTOBER 25, 2017 PAGE 4 After artificial fill is removed, the upper 12 inches of the alluvium will require, at a minimum, some removal and/or processing efforts to be considered suitable for the support of the proposed site improvements. Locally deeper processing/removals may be necessary. Refer to the "Recommendations Earthwork Construction" section of this report for specific site preparation recommendations. SURFACE & GROUND WATER Ground water was encountered during our field investigation at a depth of 3.8' and 13.2' below existing ground surface in the northern portion of the property. Irrigation ditches exist adjacent to the site and they transmit water on a periodic basis. Generally, irrigation ditches and canals will locally influence ground water during the irrigation season (i.e., May through October). If encountered, wet materials should be spread out and air-dried or mixed with drier soils to reduce their moisture content as appropriate for fill placement. Ground water is not anticipated to adversely affect planned development, provided that earthwork construction methods comply with recommendations contained in this report or those made subsequent to review of the improvement plan(s). GTI assumes that the design civil engineer of record will evaluate the site for potential flooding and set grades such that the improvements are adequately protected. These observations reflect conditions at the time of this investigation and do not preclude changes in local ground water conditions in the future from natural causes, damaged structures (lines, pipes etc.), or heavy irrigation. The groundwater monitoring results obtained are depicted in a table format in Appendix C and in a location map is presented in Figure 2. TECTONIC FAULTING AND REGIONAL SEISMICITY The site is situated in an area of active as well as potentially active tectonic faults, however no faults were observed during our field evaluation. There are a number of faults in the regional area, which are considered active and would have an affect on the site in the form of ground shaking, should they be the source of an earthquake. It is reasonable to assume that structures built in this area will be subject to at least one seismic event during their life, therefore, it is recommended that all structures be designed and constructed in accordance with the International Building Code (IBC). Based on our experience in the general vicinity, references in our library, field evaluation of the site, a Seismic Design Site Class Designation of `D' may be used for seismic design. Secondary Seismic Constraints The following list includes other potential seismic related hazards that have been evaluated with respect to the site, but in our opinion, the potential for these seismically related constraints to affect the site is considered negligible. * Liquefaction * Dynamic Settlements Surface Fault Rupture * Ground Lurching or Shallow Ground Rupture FRANKLIN AND TEN MILE LAND DEVELOPMENT PARTNERS, LLC PROJECT NO. 1905-ID3 OCTOBER 25, 2017 PAGE 5 Summary It is important to keep in perspective that if a seismic event were to occur on any major fault, intense ground shaking could be induced to this general area. Potential damage to any settlement sensitive structures would likely be greatest from the vibrations and impelling force caused by the inertia of the structures mass than that created from secondary seismic constraints. Considering the subsurface soil conditions and local seismicity, it is estimated that the site has a low risk associated with the potential for these phenomenon to occur and adversely affect surface improvements. These potential risks are no greater at this site than they are for other structures and improvements developed on the alluvial materials in this vicinity. RESULTS OF LABORATORY TESTING Laboratory tests were performed on representative samples of the onsite earth materials in order to evaluate their physical and chemical characteristics. The tests performed and the results obtained are presented in Appendix D. CONCLUSIONS Based on our field exploration, laboratory testing and engineering analyses, it is our opinion that the subject site is suited for development from a geotechnical engineering viewpoint. The recommendations presented herein should be incorporated into the final design, grading, and construction phases of development. The engineering analyses performed concerning site preparation and the recommendations presented below, have been completed using the information provided to us regarding site development. In the event that the information concerning proposed development is not correct, the conclusion and recommendations contained in this report shall not be considered valid unless the changes are reviewed and conclusions of this report are modified or approved in writing by this office. RECOMMENDATIONS - EARTHWORK CONSTRUCTION General All grading should conform to the International Building Code (IBC) and the requirements of the City of Meridian and/or Ada County except where specifically superseded in the text of this report. During earthwork construction, all removals, drain systems, slopes, and the general grading procedures of the contractor should be observed and the fill selectively tested. Based on the classification of the site soils encountered, we recommend that site construction be undertaken during the dry weather seasons. If grading is undertaken during the wet periods of the year, pumping and rutting of the site soils is anticipated. If pumping and rutting conditions occur, and loose saturated disturbed areas are created, the soils shall be removed to undisturbed soil or be replaced/recompacted to structural fill requirements. If further soil stabilization techniques are required during future grading activities, GTI can provide further recommendations at that time. If unusual or unexpected conditions are exposed in the field, they should be reviewed by this office and FRANKLIN AND TEN MILE LAND DEVELOPMENT PARTNERS, LLC PROJECT NO. 1905-1133 OCTOBER 25, 2017 PAGE 6 if warranted, modified and/or additional recommendations will be offered. It is recommended that the earthwork contractor(s) perform their own independent reconnaissance of the site to observe field conditions first hand. If the contractor(s) should have any questions regarding site conditions, site preparation, or the remedial recommendations provided, they should contact an engineer at GeoTek for any necessary clarifications prior to submitting earthwork bids. All applicable requirements of local and national construction and general industry safety orders, the Occupational Safety and Health Act, and the Construction Safety Act should be met. Demolition The following recommendations are provided as guidelines in the event a structure is encountered that are not intended to remain. I. All existing surface or subsurface structures (not intended to remain), within the area to be developed, should be razed and moved off site. 2. If a septic tank (to be abandoned or below a proposed improvement) is located within the project site, it is recommended that it be pumped out and with few exceptions likely removed. Any leach lines, seepage pits, or other pipes associated with this structure should also be removed or properly abandoned. 3. If any wells are encountered, an attempt should be made to identify the owner and purpose of the well. Well abandonment should adhere to the recommendations provided by the Idaho Department of Water Resources, the Public Health Department, or any other government agencies. If the well is located in the area of a proposed structure, these recommendations should be reviewed by GTI and if warranted, additional geotechnical recommendations will be offered. Removals/Processing - General Presented below are removal/processing recommendations for the various soils encountered on the project. Debris, vegetation, and other deleterious material should be stripped/removed from areas proposed for structural improvements. Based on a review of the exploratory logs and our site reconnaissance, after the artificial fill is removed (upper 12 inches, where observed), a minimum removal/processing depth of 12 inches into alluvial materials should be accomplished across the site. If the left in place soils can be scarified to encounter a competent layer below; they may be processed in place; otherwise, they should be removed to competent material. Locally deeper removals/processing may be necessary based on the field conditions exposed. Beneath the foundations, a minimum of 12 inches of compacted structural fill, meeting the requirements of the Structural Fill and Import Soils section of this report, should be moisture conditioned and compacted to provide a more uniform foundation support. Structural fill should extend a minimum of 12 inches horizontally, from the edge of the footings, for each 12 inches of thickness placed below the footings. A minimum relative compaction of 95 percent of the laboratory maximum modified density (ASTM D 1557) at moisture content of optimum or above is necessary to generate any near surface settlements. Locally deeper removals/processing may be necessary based on the conditions exposed. Removal bottoms should be checked by a representative of GeoTek, Inc. to see if deeper removals are necessary. FRANKLIN AND TEN MILE LAND DEVELOPMENT PARTNERS, LLC PROJECT NO. 1905-ID3 OCTOBER 25, 2017 PAGE 7 If very hard cemented materials are encountered during over -excavation, excavation may potentially be terminated, but this will need to be determined on a case by case basis by a representative of GTI. Foundations for the proposed structures may be founded on cemented material; however, in order to avoid the potential for differential settlement, the entire foundation would need to be supported entirely on the cemented material. If this is not possible, cemented materials should be removed to a minimum depth of 12 inches below the bottom of the footing and replaced with compacted structural fill. This can best be determined in the field based upon the conditions exposed. Termination of any excavation on cemented soils will need to be reviewed by GTI and the owner. If existing improvements or property line restrictions limit removals, condition specific recommendations would be provided on a case-by-case basis. During earthwork construction, care should be taken by the contractor so that adverse ground movements or settlements are not generated affecting existing improvements. Transitional Pads Transitional pads are defined in this report as pads which are partially cut and partially fill. To mitigate some of the differential settlement which will occur on transitional pads, the cut side should be over- excavated/processed to a minimum depth equal to 2 feet below the bottom of the footings or to the depth of the fill, which ever is less. On transitional pads with more than 7.5 feet of fill, plans need to be reviewed by GTI and site-specific recommendations will be provided. Excavation Difficulty We anticipate that the onsite soils can be excavated with conventional earthwork. Seasonal conditions could cause wet soil conditions to occur onsite. Depending on the depth of cuts, it should be expected that special excavation and fill placement measures may be necessary. Wet materials should be spread out and air-dried or mixed with drier soils to reduce their moisture content to the appropriate level for fill placement. Frozen soils, if encountered, should be removed and allowed to thaw prior to any fill placement or construction. Removal bottoms should be checked by a representative of GTI to see if deeper removals are necessary. Fill Placement Subsequent to completing removals/processing and ground preparation, the excavated onsite and/or imported soils may be placed in relatively thin lifts (less than 8 inches thick), cleaned of vegetation and debris, brought to at least optimum moisture content, and compacted to a minimum relative compaction of 95 percent of the laboratory standard (ASTM D 1557). Structural Fill and Import Soils Potentially, soils will be imported to the site for earthwork construction purposes. A sample of any intended import material should first be submitted to GTI so that, if necessary, additional laboratory or chemical testing can be performed to verify that the intended import material is compatible with onsite soils. In general, structural fill and import soils should be within the following minimum guidelines: FRANKLIN AND TEN MILE LAND DEVELOPMENT PARTNERS, LLC PROJECT NO. 1905-ID3 * Free of organic matter and debris. * Maintain less than 0.2 percent sulfate content. * Maintain less than 3.0 percent soluble material. * Maintain less than 0.02 percent soluble chlorides. * Maintain less than 0.2 percent sodium sulfate content. * Maintain a Plasticity Index less than 12 (i.e., low expansive). * One hundred percent passing the six-inch screen. * At least seventy-five percent passing a three-inch screen. OCTOBER 25, 2017 PAGE 8 Observation and Testing During earthwork construction all removal/processing and the general grading procedures should be observed and the fill selectively tested by a representative (s) of GTI. If unusual or unexpected conditions are exposed in the field, they should be reviewed by GTI and if warranted, modified and/or additional recommendations will be offered. Ground Water Ground water was encountered during our field investigation at a depth of 3.8' and 13.2' below existing ground surface. Based on site conditions in the future, a transient high ground water condition could develop over a clay or less permeable layer and this condition could generate down gradient seepage. The possible effect these layers could have on this and adjacent sites should be considered, and can best be evaluated in the field during grading. If warranted by exposed field conditions, it may be recommended that a drainage system be established to collect and convey any subsurface water to an appropriate location for drainage. Typically, potential areas of seepage are difficult to identify prior to their occurrence; therefore, it is often best to adopt a "wait and see" approach to determine if any seepage conditions do develop, at which time specific recommendation to mitigate an identified condition can be provided. Earthwork Settlements Ground settlement should be anticipated due to primary consolidation and secondary compression. The total amount of settlement and time over which it occurs is dependent upon various factors, including material type, depth of fill, depth of removals, initial and final moisture content, and in-place density of subsurface materials. Compacted fills, to the heights anticipated, are not generally prone to excessive settlement. However, some settlement of the native alluvium is expected and the majority of this settlement is anticipated to occur during grading. Slope Stability No significantly high (greater than ten feet) slopes are anticipated to be constructed onsite. All slopes should be designed at gradients of 2 to I (Horizontal to Vertical) or flatter. All slopes should be constructed in accordance with the minimum requirements of the City of Meridian and/or Ada County and the International Building Code. Cut and fill slopes are anticipated to perform adequately in the future with respect to gross and surficial stability if the soil materials are maintained in a solid to semi-solid state (as defined by the soils Atterberg Limits) and are limited to the heights prescribed herein. GeoTek, Inc. FRANKLIN AND TEN MILE LAND DEVELOPMENT PARTNERS, LLC PROJECT NO. 1905-ID3 OCTOBER 25, 2017 PAGE 9 The importance of proper compaction to the face of a slope cannot be overemphasized. In order to achieve proper compaction, one or more of the three following methods should be employed by the contractor following implementation of typical slope construction guidelines: 1) track walk the slopes at grade, 2) use a combination of cheeps foot roller and track walking, or 3) overfill the slope 3 to 5 feet laterally and cut it back to grade. Random testing will be performed to verify compaction to the face of the slope. If the tests do not meet the minimum recommendation of 90 percent relative compaction, the contractor will be informed and additional compactive efforts recommended. A final evaluation of cut slopes during grading will be necessary in order to identify any areas of adverse conditions. The need for remedial stabilization measures should be based on observations made during grading by a representative of this office. Based on our observations, and if warranted, specific remedial recommendations will be offered for stabilization. RECOMMENDATIONS — FOUNDATIONS General Foundation design and construction recommendations are based on preliminary laboratory testing and engineering analysis performed on near surface soils. The proposed foundation systems should be designed and constructed in accordance with the guidelines contained herein and in the International Building Code. Based on our experience in the area, the soils onsite should have a negligible corrosive potential to concrete and metal, materials selected for construction purposes should be resistant to corrosion. Where permitted by building code, PVC pipe should be utilized. All concrete should be designed, mixed, placed, finished, and cured in accordance with the guidelines presented by the Portland Cement Association (PCA) and the American Concrete Institute (ACI). Based on our grading recommendations, the soils beneath the foundations are anticipated to have low expansion potential. Therefore, foundation recommendations for low expansive soil conditions are provided below. If more expansive soils are encountered, the pad(s) will either need to be regraded and the more expansive soils removed by the contractor or increased foundation recommendations will need to be provided. Conventional Foundation Recommendations Column loads are anticipated to be 50 kips or less while wall loads are expected to be 3 kips per lineal foot or less. The conventional recommendations provided are from a geotechnical engineering perspective (i.e., for expansive conditions) and are not meant to supersede the design by the project's structural engineer. Preliminary recommendations for foundation design and construction are presented below. The specific criteria to be used should be verified on evaluation of the proposed buildings, structural loads, and expansion and chemical testing performed after grading is complete. FRANKLIN AND TEN MILE LAND DEVELOPMENT PARTNERS, LLC PROJECT NO. 1905-ID3 OCTOBER 25, 2017 PAGE 10 The bearing values indicated are for the total dead plus frequently applied live loads and may be increased by one third for short duration loading which includes the effects of wind or seismic forces. When combining passive pressure and friction for lateral resistance, the passive component should be reduced by one third. A grade beam, reinforced as below and at least 12 inches wide, should be utilized across all large entrances. The base of the grade beam should be at the same elevation as the bottom of the adjacent footings. Footings should be founded at a minimum depth of 24 inches below lowest adjacent ground surface as required by local codes to extend below the frost line. Reinforcement for spread footings should be designed by the project's structural engineer. For foundations systems including a crawl space, it is recommended that it be designed so that water is not allowed to penetrate the crawl space. Proper grading and backfill for the foundations is critical and should adhere to the "fill placement" and "drainage" recommendations of this evaluation as well as local building codes. The coefficient of friction and passive earth pressure values recommended are working values. Strip footings should have a minimum width of one foot and spread footings should have a minimum soil to concrete area of four square feet. Increases are allowed for the bearing capacity of the footings at a rate of 250 pounds per square foot for each additional foot of width and 250 pounds per square foot for each additional foot of depth into the recommended bearing material, up to a maximum outlined. If the bearing value exceeds 3,000 psf, an additional review by GTI is recommended. As mentioned earlier, the structural fill should be moisture conditioned and compacted a minimum of 12 inches below bottom of footings. Prior to the placement of concrete, moisture should be added to the subgrade soils to minimize water loss of the concrete during placement and curing. If the grading recommendations presented in this report are complied with, proposed concrete floor slabs may be supported on a 6 -inch layer of compacted 3/4 -inch aggregate base material. A structural engineer should evaluate the proposed loading and determine the slab thickness, concrete strength, and the locations and size of the reinforcing steel. Modulus of subgrade reaction (k) may be used in the design of the floor slab supporting heavy truck traffic, forklifts, machine foundations, and heavy storage areas. Based on typical R -value test results and the interrelationships published by the Portland Cement Association for "R" -Value (resistance value) ys Modulus of Subgrade Reaction, an approximate k -value (modulus of subgrade reaction) of 125 pounds per square inch per inch may be utilized for slab design. Minimum Structural Fill Minimum Allowable Passive Maximum Footing Type Depth Below Footing Bearing Coefficient Earth Earth Footing Depth Pressure of Friction Pressure Pressure Bottom (inches) (psf) (psf/ft) (psf) inches Strip or Spread 12 24 1,500 0.35 250 3,000 The coefficient of friction and passive earth pressure values recommended are working values. Strip footings should have a minimum width of one foot and spread footings should have a minimum soil to concrete area of four square feet. Increases are allowed for the bearing capacity of the footings at a rate of 250 pounds per square foot for each additional foot of width and 250 pounds per square foot for each additional foot of depth into the recommended bearing material, up to a maximum outlined. If the bearing value exceeds 3,000 psf, an additional review by GTI is recommended. As mentioned earlier, the structural fill should be moisture conditioned and compacted a minimum of 12 inches below bottom of footings. Prior to the placement of concrete, moisture should be added to the subgrade soils to minimize water loss of the concrete during placement and curing. If the grading recommendations presented in this report are complied with, proposed concrete floor slabs may be supported on a 6 -inch layer of compacted 3/4 -inch aggregate base material. A structural engineer should evaluate the proposed loading and determine the slab thickness, concrete strength, and the locations and size of the reinforcing steel. Modulus of subgrade reaction (k) may be used in the design of the floor slab supporting heavy truck traffic, forklifts, machine foundations, and heavy storage areas. Based on typical R -value test results and the interrelationships published by the Portland Cement Association for "R" -Value (resistance value) ys Modulus of Subgrade Reaction, an approximate k -value (modulus of subgrade reaction) of 125 pounds per square inch per inch may be utilized for slab design. FRANKLIN AND TEN MILE LAND DEVELOPMENT PARTNERS, LLC PROJECT NO. 1905-ID3 OCTOBER 2S, 2017 PAGE I 1 It is recommended that a plastic water vapor retarder be utilized below the slab. The vapor retarder should conform to the specifications presented in ASTM E 1745-97 and should be placed as described in ASTM E1643-98 and the Guide for Concrete Floor and Slab Construction, published by the American Concrete Institute (ACI 302.1 R-96). A minimum ten -mil thick vapor retarder should be placed on a minimum 6 -inch thick layer of aggregate base material and a 2 -inch layer of select sand should be placed over the vapor retarder. The vapor retarder should be lapped adequately to provide a continuous protection under the entire slab. Foundation Settlement Provided that the recommendations contained in this report are incorporated into final design and construction phase of development, total settlement is estimated to be less than one inch and differential settlement is estimated to be less than 0.75 inches for a 25 -foot span. Two-way angular distortions due to settlements are not estimated to exceed 1/400. The structures should be loaded uniformly so as to avoid any localized settlements. PAVEMENT SECTIONS Pavement sections presented in the following table are based on an R -value of 22, assumed traffic index(s) for development and estimated traffic index(s) for development. These pavement sections are presented for planning purposes only and should be verified based on specific laboratory testing performed subsequent to rough grading of the site. Pavement Construction and Maintenance All section changes should be properly transitioned. If adverse conditions are encountered during the preparation of subgrade materials, special construction methods may need to be employed. All subgrade materials should be processed to a minimum depth of 12 inches and compacted to a minimum relative compaction of 90 percent near optimum moisture content. All aggregate base should be compacted to a minimum relative compaction of 95 percent at optimum moisture content. The recommended pavement sections provided are meant as minimums. If thinner or highly variable pavement sections are constructed, increased maintenance and repair should be expected. If the ADT (average daily traffic) or ADTT (average daily truck traffic) increases beyond that intended, as reflected by the traffic index(s) used for design, increased maintenance and repair could be required for the pavement section. Positive site drainage should be maintained at all times. Water should not be allowed to pond or seep into the ground. If planters or landscaping are adjacent to paved areas, measures should be taken to minimize the potential for water to enter the pavement section. FRANKLIN AND TEN MILE LAND DEVELOPMENT PARTNERS, LLC PROJECT NO. 1905-1133 Hot -Mix Asphalt Pavement Sections OCTOBER 25, 2017 PAGE 12 *Subbase gradation specification requirement per the current edition of the Idaho State Public Works Construction (ISPWC) Manual. OTHER RECOMMENDATIONS Site Improvements As is commonly known, expansive soils are problematic with respect to the design, construction and long term performance of concrete flatwork. Due to the nature of concrete flatwork, it is essentially impossible to totally mitigate the effects of soil expansion. Typical measures to control soil expansion for structures include; low expansive soil caps, deepened foundation system, increased structural design, and soil presaturation. As they are generally not cost effective, these measures are very seldom utilized for flatwork because it's less costly to simply replace any damaged or distressed sections than to "structurally" design them. Even if "structural" design parameters are applied to flatwork construction, there would still be relative movements between adjoining types of structures and other improvements (e.g., curb and sidewalk). This is particularly true as the level of care during construction of flatwork is often not as meticulous as that for structures. Unfortunately, it is fairly common practice for flatwork to be poured on subgrade soils, which have been allowed to dry out since site grading. Generally after flatwork construction is completed, landscape irrigation begins, utility lines are pressurized, and drainage systems are utilized; presenting the potential for water to enter the dry subgrade soils, causing the soil to expand. Recommendations for exterior concrete flatwork design and construction can be provided upon request. If, in the future, any additional improvements are planned for the site, recommendations concerning the geological or geotechnical aspects of design and construction of said improvements could be provided upon request. This office should be notified in advance of any fill placement, grading, or trench backfilling after rough grading has been completed. This includes any grading, utility trench and retaining wall backfills. MINIMUM MINIMUM AGGREGATE ASSUMED TRAFFIC SUBGRADE ASPHALT THICKNESS (in.) Aggregate Subbase* RIGHT -OF -AWAY R -VALUE CONCRETE THICKNESS Base (3/4" (Uncrushed (in.) minus) Aggregate) Parking and Drives No Truck Access 22 2.5 4.0 9.0 TI = 6.0 Truck Access 22 3.0 6.0 12.0 TI = 8.0 Heavy Truck Access 22 4.0 8.0 14.0 TI = 10.0 *Subbase gradation specification requirement per the current edition of the Idaho State Public Works Construction (ISPWC) Manual. OTHER RECOMMENDATIONS Site Improvements As is commonly known, expansive soils are problematic with respect to the design, construction and long term performance of concrete flatwork. Due to the nature of concrete flatwork, it is essentially impossible to totally mitigate the effects of soil expansion. Typical measures to control soil expansion for structures include; low expansive soil caps, deepened foundation system, increased structural design, and soil presaturation. As they are generally not cost effective, these measures are very seldom utilized for flatwork because it's less costly to simply replace any damaged or distressed sections than to "structurally" design them. Even if "structural" design parameters are applied to flatwork construction, there would still be relative movements between adjoining types of structures and other improvements (e.g., curb and sidewalk). This is particularly true as the level of care during construction of flatwork is often not as meticulous as that for structures. Unfortunately, it is fairly common practice for flatwork to be poured on subgrade soils, which have been allowed to dry out since site grading. Generally after flatwork construction is completed, landscape irrigation begins, utility lines are pressurized, and drainage systems are utilized; presenting the potential for water to enter the dry subgrade soils, causing the soil to expand. Recommendations for exterior concrete flatwork design and construction can be provided upon request. If, in the future, any additional improvements are planned for the site, recommendations concerning the geological or geotechnical aspects of design and construction of said improvements could be provided upon request. This office should be notified in advance of any fill placement, grading, or trench backfilling after rough grading has been completed. This includes any grading, utility trench and retaining wall backfills. FRANKLIN AND TEN MILE LAND DEVELOPMENT PARTNERS, LLC PROJECT NO. 1905-1133 OCTOBER 25, 2017 PAGE 13 Landscape Maintenance and Planting Water has been shown to weaken the inherent strength of all earth materials. Slope stability is significantly reduced by overly wet conditions. Graded slopes constructed within and utilizing onsite materials would be erosive. Eroded debris may be minimized and surficial slope stability enhanced by establishing and maintaining a suitable vegetation cover as soon as possible after construction. Compaction to the face of fill slopes would tend to minimize short-term erosion until vegetation is established. Plants selected for landscaping should be lightweight, deep-rooted types, which require little water and are capable of surviving the prevailing climate. From a geotechnical standpoint leaching is not recommended for establishing landscaping. If the surface soils are processed for the purpose of adding amendments, they should be recompacted to 90 percent compaction. Only the amount of irrigation necessary to sustain plant life should be provided. Over watering the landscape areas could adversely affect proposed site improvements. We recommend that any proposed open bottom planter areas adjacent to proposed structures, be eliminated for a minimum distance of 5 feet and desert landscape using xeriscape technology be used outside of this buffer zone. As an alternative, closed bottom type planters could be utilized. An outlet, placed in the bottom of the planter, could be installed to direct drainage away from structures or any exterior concrete flatwork. Irrigation timers should be adjusted on a monthly basis. Soil Corrosion Based on our experience in the area, the soils onsite should have a negligible corrosive potential to concrete and metal, materials selected for construction purposes should be resistant to corrosion. Where permitted by building code PVC pipe should be utilized. All concrete should be designed, mixed, placed, finished, and cured in accordance with the guidelines presented by the Portland Cement Association (PCA) and the American Concrete Institute (ACI). Trench Excavation All footing trench excavations should be observed by a representative of this office prior to placing reinforcement. Footing trench spoil and any excess soils generated from utility trench excavations should be compacted to a minimum relative compaction of 90 percent if not removed from the site. Considering the nature of the onsite soils, it should be anticipated that caving or sloughing could be a factor in excavations. Shoring or excavating the trench walls and slopes to the angle of repose (typically 25 to 45 degrees) may be necessary and should be anticipated in non-cemented soils. All excavations should be observed by one of our representatives and conform to national and local safety codes. FRANKLIN AND TEN MILE LAND DEVELOPMENT PARTNERS, LLC PROJECT NO. 1905-1133 OCTOBER 25, 2017 PAGE 14 Onsite Utility Trench Backfill Considering the overall nature of the soil encountered onsite, it should be anticipated that materials will need to be imported to the site for use as pipe bedding and pipe zone material. All utility trench backfill should be brought to near optimum moisture content and then compacted to obtain a minimum relative compaction of 90 percent of the laboratory standard. Compaction testing and observation, along with probing should be performed to verify the desired results. Sand backfill, unless excavated from the trench, should not be used adjacent to perimeter footings or in trenches on slopes. Compaction testing and observation, along with probing should be performed to verify the desired results. Sand backfill, unless excavated from the trench, should not be used adjacent to perimeter footings or in trenches on slopes. Compaction testing and observation, along with probing should be performed to verify the desired results. Offsite utility trenches should be compacted to a minimum of 90 relative compaction. Compaction testing and observation, along with probing should be performed to verify the desired results. Drainage Positive site drainage should be maintained at all times in accordance with the IBC. Drainage should not flow uncontrolled down any descending slope. Water should be directed away from foundations and not allowed to pond and/or seep into the ground. Pad drainage should be directed toward the street or other approved area. The ground immediately adjacent to the foundation shall be sloped away from the building at a minimum of 5 -percent for a minimum distance of 10 feet measured perpendicularly to the face of the wall. If physical obstructions prohibit 10 feet of horizontal distance, a 5 -percent slope shall be provided to an approved alternate method of diverting water away from the foundation. Swales used for this purpose shall be sloped a minimum of 2 -percent where located within 10 feet of the building foundation. Impervious surfaces within 10 feet of the building foundation shall be sloped a minimum of 2 -percent away from the building. Roof gutters and down spouts should be utilized to control roof drainage. Down spouts should outlet onto paved areas or a minimum of five feet from proposed structures or into a subsurface drainage system. Areas of seepage may develop due to irrigation or heavy rainfall. Minimizing irrigation will lessen this potential. If areas of seepage develop, recommendations for minimizing this effect could be provided upon request. 1:2A11`►■l:k'/1'.'1 Final grading, foundation, and improvement plans should be submitted to this office for review and comment as they become available, to minimize any misunderstandings between the plans and recommendations presented herein. In addition, foundation excavations and earthwork construction performed on the site should be observed and tested by this office. If conditions are found to differ substantially from those stated, appropriate recommendations would be offered at that time. FRANKLIN AND TEN MILE OCTOBER 25, 2017 LAND DEVELOPMENT PARTNERS, LLC PAGE 15 PROJECT NO. 1905-1133 LIMITATIONS The materials encountered on the project site and utilized in our laboratory study are believed representative of the area; however, soil materials vary in character between excavations and conditions exposed during mass grading. Site conditions may vary due to seasonal changes or other factors. GeoTek, Inc. assumes no responsibility or liability for work, testing, or recommendations performed or provided by others. Since our study is based upon the site materials observed, selective laboratory testing and engineering analysis, the conclusions and recommendations are professional opinions. These opinions have been derived in accordance with current standards of practice and no warranty is expressed or implied. Standards of practice are subject to change with time. The opportunity to be of service is greatly appreciated. If you have any questions concerning this report or if we may be of further assistance, please do not hesitate to contact the undersigned. Respectfully submitted, GeoTek, Inc. Tyler Lydeen, EI Staff Professional G(' -Cot t C�, onc. David C. Waite, PE Senior Engineer SOnna ^t Vi GTnli 4" 2� W (1)erry L,1 Settlers Park E IJ I k- i WA CL `p"i{ r ii -P Avi- i. i�f3rlilli �� t'xi� f" n •L 4� Roaring Springs Water Park W Meridian E F I. -i jj~'t' I Vr, Cn APPROXIMATE SITE LOCATION JIV Source: Google Maps 2017, GeoTek Field Observations, 2017. Not to Scale FIGURE I SITEVICINITY MAP Franklin and Ten Mile Meridian, Idaho G E O T E K Prepared for: Landmark Development Partners, LLC GEOTECHNICAL I ENVIRONMENTAL I MATERIALS Project No.: Report Date: I Drawn By: 320 E. Corporate Or, Suite 300, Meridian, ID 83642 1905-ID3 Oct 2017 TL (208) 888-7010 (phone) / (208) 888-7924 (FAX) I FA J ;J 42��� REFERENCES Ada County Highway District Development Policy Manual, Revised by Resolution No. 690, October 2003 ASTM, 200, "Soil and Rock: American Society for Testing and Materials," vol. 4.08 for ASTM test methods D-420 to D-4914, 153 standards, 1,026 pages; and vol. 4.09 for ASTM test method D- 4943 to highest number. Breckinridge, R.M., Lewis, R.S., Adema, G.W., Weisz, D.W., 2003, Map of Miocene and Younger Faults in Idaho, Idaho Geological Survey, University of Idaho Day, Robert W., 1999, Geotechnical and Foundation Engineering — Design and Construction Day, Robert W., 2002, Geotechnical Earthquake Engineering Handbook GeoTek, Inc., In-house proprietary information. Idaho Department of Water Resources, Treasure Valley Hydrology — Geology Idaho Department of Water Resources, Well Information, Well Driller Reports, 2015 Idaho Transportation Department CD-ROM Publications Johnson, Bruce R. and Raines, Gary L., 1995, Digital representation of the Idaho state geologic map: a contribution to the Interior Columbia Basin Ecosystem Management Project. USGS Open -File Report 95-690 Malde, H.E., 1991. Quaternary geology and structural history of the Snake River Plain, Idaho and Oregon. In: The Geology of North America, Quaternary Nonglacial Geology: Conterminous U.S., Vol. K-2, 252-281 pp. Othberg, K.L., 1994. Geology and geomorphology of the Boise Valley and adjoining areas, western Snake River Plain, Idaho. Idaho Geological Survey Bulletin 29: 54 pp. USGS, 2003, Seismic Hazard Map of Idaho, Peak Acceleration (%g) with 2% Probability of Exceedance in 50 years. g r 'i, TEST PIT LOG GENERAL NOTES CONSISTENCY OF FINE-GRAINED SOILS Unconfined Compressive Strength, Qu, psf Standard Penetration or N - Value (SS) Blows/Ft Consistency < 500 <2 Very Soft 500-1,000 2 - 3 Soft 1,001 - 2,000 4 - 7 Firm 2,001 - 4,000 8-16 Stiff 4,001 - 8,000 17-32 Very Stiff > 8,001 32+ Hard RELATIVE DENSITY OF COARSE-GRAINED SOILS' Standard Penetration (SPT) or N -Value (SS) Blows/Ft Relative Density 0 - 3 Very Loose 4 - 9 Loose 10-29 Medium Dense 30-49 Dense 50+ ery Dense SPT penetration test using 140 pound hammer, with 30 inch free fall on 2 inch outside diameter(1-3/8 ID) sampler For ring sampler using 140 Ib hammer, with a 30 inch free fall on 3 inch outside diameter (2-1/2 ID) sample, use N -value x 0.7 to get Standard N -value For fine grained soil consistency, thumb penetration used per ASTM D-2488 RELATIVE PROPORTIONS OF SAND AND GRAVEL Descriptive Term of other constituents Percent of Dry Weight Trace < 15 With 15-29 Modifier > 30 GRAIN SIZE TERMINOLOGY Major Component of Sample Particle Size Boulders Over 12 inches Cobbles 3 inches to 12 inches Gravel #4 Sieve to 3 inches Sand #200 Sieve to #4 Sieve Silt or Clav Passing #200 Sieve RELATIVE HARDNESS OF CEMENTED SOILS (CALICHE) Description General Characteristics Very Dense to Moderately Hard Partially Cemented Granular Soil - Can be carved with a knife and broken with force by hand. Very Stiff to Moderately Hard Partially Cemented Fine -Grained Soil - Can be carved with a knife and broken with force by hand. Moderately Hard Moderate hammer blow required to break a sample Hard Heavy hammer blow required to break a sample Very Hard Repeated heavy hammer blow required to break a sample LOG LEGEND SAMPLING MATERIAL DESCRIPTION Soil Pattern7GP-GM mbol USCS Classification NR So Artificial Fill MH GW Poorly/Well graded GRAVEL .. , F Silty GRAVEL H Hard Clayey GRAVEL Medium Dense GW -GM Poorly/Well graded GRAVEL with Silt VH GW -GC Poorly/Well graded GRAVEL with Clay Dense orSW Poorly/Well graded SAND SM Silty SAND Very Dense Sc Clayey SAND SP -SM or SW -SM Poorly/Well graded SAND with Silt SP -SC or SW -SC Poorly/Well graded SAND with Clay SC -SM Silty Clayey SAND ML SILT MH Elastic SILT CL -ML Silty CLAY CL Lean CLAY CH Fat CLAY PCEM PARTIALLY CEMENTED CEM CEMENTED BDR BEDROCK SAMPLING Cohesionless Soils Cohesive Soils SPT Ring Sample No Recovery Bulk Sample Water Table VL NR So Soft CONSISTENCY Cohesionless Soils Cohesive Soils Cementation VL Very Loose So Soft MH Moderately Hard L Loose F Firm H Hard MD Medium Dense S Stiff VH Very Hard D Dense VS Very Stiff VD Very Dense TEST PIT L 0 G LOGGED BY: TL PROJECT #: 1905-ID3 METHOD: Backhoe PROJECT: Franklin and Ten Mile EXCAVATOR: Just Dig It CLIENT: T -O Engineers, Inc DATE: 10/9/17 G E O T E K LOCATION: Franklin Rd and Ten Mile Rd ELEVATION: SAMPLES c �, N TEST PIT NUMBER: TP -1 y REMARKS V p EO <n m N O MATERIAL DESCRIPTION AND COMMENTS ML Brown Sandy SILT w/ Organics; Slightly Moist So 1 ML Tan Sandy SILT; Slightly Moist F 2 3 4 Percolation Test Installed at 4.0' SP Tan Poorly Graded SAND; Slightly Moist to Moist MD - 5 D 6 7 8 9 ML Brown SILT w/ Varying amounts of Sand Content; Moist to S Saturated 10 11 12 Ground Water Measured at 13.2' per measurement 13 10/24/2017 14 END OF TEST PIT @ 14.5- 15- Groundwater Encountered 16- 617181920 17- 18- 19- 20 320 E. Corporate Drive, Suite 300, Meridian, Idaho 83642 (208) 888-7010 Fax: (208) 888-7924 TEST PIT LOG 320 LOGGED BY: TL PROJECT #: 1905-ID3 METHOD: Backhoe '--0j PROJECT: Franklin and Ten Mile EXCAVATOR: Just Dig It CLIENT: T -O Engineers, Inc DATE: 10/9/17 E 0 ■ T K LOCATION: Franklin Rd and Ten Mile Rd ELEVATION: SAMPLES cA T CC v N TEST PIT NUMBER: TP -2 V a. REMARKS D a y C N N G p M V) m N MATERIAL DESCRIPTION AND COMMENTS ML Dark Brown SILT w/ Organics; Moist So 1 ML Dark Brown SILT; Moist F 2 CL -ML Grey Sandy Silty CLAY w/ Some Gravel; Moist S 3 Ground Water Measured 4 at 3.8' per measurement 10/24/2017 5 6 7 SM Brown Silty SAND w/ Gravel; Moist to Saturated D 8 9 G { N&: 10- 11 12 END OF TEST PIT @ 11.5' Groundwater Encountered 13- 314151617181920 14- 15- 16- 17- 18- 19- 20- 320 E. Corporate Drive, Suite 300, Meridian, Idaho 83642 (208) 888-7010 Fax: (208) 888-7924 TEST PIT L 0 G LOGGED BY: TL PROJECT #: 1905-I D3 METHOD: Backhoe PROJECT: Franklin and Ten Mile EXCAVATOR: Just Dig It CLIENT: T -O Engineers, Inc DATE: 10/9/17 G E 0 T E K LOCATION: Franklin Rd and Ten Mile Rd ELEVATION: SAMPLES c T N TEST PIT NUMBER: TP -3 REMARKS CL c CL E o 4n v _H o v, m N = MATERIAL DESCRIPTION AND COMMENTS ML Tan Sandy SILT w/ Organics; Slightly Moist So 1 ML Tan Sandy SILT; Slightly Moist F 2 SP Brown Poorly Graded SAND; Slightly Moist D 3 4 5 SM Brown Silty SAND; Moist D �r 6 SP Brown Poorly Graded Fine SAND; Moist to Saturated D 7 8 9 ML Brown SILT w/ Sand; Saturated S 10 11 — END OF TEST @ 11.0' Groundwater Encountered 12 13 14 15 16 17 18 19 20 320 E. Corporate Drive, Suite 300, Meridian, Idaho 83642 (208) 888-7010 Fax: (208) 888-7924 TEST PIT L 0 G 320 LOGGED BY: TL PROJECT #: 1905-ID3 METHOD: Backhoe PROJECT: Franklin and Ten Mile EXCAVATOR: Just Dig It CLIENT: T -O Engineers, Inc DATE: 10/9/17 T G E 0 ® E K LOCATION: Franklin Rd and Ten Mile Rd ELEVATION: SAMPLES 0 N TEST PIT NUMBER: TP -4 H a a REMARKS d D Q, N C N N O O v> m MATERIAL DESCRIPTION AND COMMENTS ML Brown Sandy SILT w/ Organics; Slightly Moist So 1 ML Brown Sandy SILT; Slightly Moist F 2 SP -SM Tan Poorly Graded SAND w/ Silt and Some Partially MD - 3 Cemented Layers; Slightly Moist D 4 5 6 ML Brown SILT w/ Sand and some Partially Cemented Layers S 7 and Fine Sand; Moist 8 9 SP Brown Poorly Graded SAND w/ Some Silt; Moist D 10- 11 ML Brown Sandy SILT; Moist S 12- 21314 13- 14— END OF TEST PIT @ 14.0' 15 Groundwater Encountered 16- 617181920 17- 18- 19- 20- 320 E. Corporate Drive, Suite 300, Meridian, Idaho 83642 (208) 888-7010 Fax: (208) 888-7924 TEST PIT LOG LOGGED BY: TL PROJECT #: 1905-ID3 METHOD: Backhoe PROJECT: Franklin and Ten Mile EXCAVATOR: Just Dig It C LIE NT: T-0 Engineers, Inc DATE: 10/9/17 G E 0 T E K LOCATION: Franklin Rd and Ten Mile Rd ELEVATION: SAMPLES CU E Cn CD REMARKS CL CL cc MATERIAL DESCRIPTION AND COMMENTS ML Brown SILT w/ Organics; Slightly Moist So ML Brown SILT; Slightly Moist F SM Brown Silty SAND; Slightly Moist D 4-- CEM Grey CEMENTED Sand; Slightly Moist H - VH 6 — SP Brown Poorly Graded SAND; Slightly Moist D Percolation Test installed at 7.5' SP Tan Poorly Graded Fine SAND D 10— SM Tan SAND w/ Silt; Moist to Saturated D 11 Groundwater Encountered 15- L 32OE.Corporate Drive, Suite 3U0.Meridian, Idaho 83842 (208) 888-7010 Fax: (208) 888-7924 rA.1 j j :1 Z FIELD TESTS AND OBSERVATIONS (I 905 -ID PERCOLATION TESTS The infiltration rate was determined by conducting percolation tests for onsite soils. The infiltration rate was determined in inches per hour in general accordance with Ada County requirements. Infiltration rate results are presented below. LOCATION INFILTRATION RATE LOCATION (Inches/Hour) (P-1) TP -I @ 4.0' 2.2 (P-2) TP -5 @ 7.5' 24.0+ GROUND WATER MONITORING RESULTS Ground water monitoring results are presented below. Ground water elevation results are recorded in feet below existing grade. + Indicates a dry reading at the bottom of the piezometer n/a Indicates that the piezometer was damaged/missing in the field and no measurements were obtained. Bold Indicates ground water was encountered in the piezometer GROUNDWATER LOCATION ELEVATION TP -1 13.2' TP -2 3.8' + Indicates a dry reading at the bottom of the piezometer n/a Indicates that the piezometer was damaged/missing in the field and no measurements were obtained. Bold Indicates ground water was encountered in the piezometer ATTERBERG LIMITS Atterberg limits were performed on representative samples in general accordance with ASTM D 4318. The results are shown in the following plates. PARTICLE SIZE ANALYSIS Sieve analyses were performed in general accordance with ASTM test method C 136 and ASTM C 117. Test results are presented in the following plates. RESISTANCE R -VALUE TESTING Tests were conducted on representative soil samples, in general accordance with Idaho test method T-8 and AASHTO T-190, to determine the soil's performance when placed in the base, subbase, or subgrade of a road subjected to traffic. R -VALUE @ 200 LOCATION psi TP- I @ 1.0' — 2.0' 22 GeoTek, Inc. 320 East Corporate give Suite 300 Meridian, ID 83642-3511 (208) 888-7010 (208) 888-7924 i www.geotekusa.com March 18, 2019 Project No. 1905 -ID LAND DEVELOPMENT PARTNERS, LLC 4685 S. Highland Dr., Suite 202 Salt Lake City, Utah 84117 Attention: Mr. James Doolin Subject: Addendum to the Geotechnical Evaluation — "Entrata Farms" — a 17.7± acre Multi - Family Residential Development Located West of N. Ten Mile Road and North of W. Franklin Road, Meridian, Idaho Reference: Geotechnical Evaluation for "Franklin and Ten Mile" - a 17.7± Acre Multi -Family Residential Located West of N. Ten Mile Road and North of W. Franklin Road, Meridian, Idaho This document presents an addendum to the above referenced Geotechnical Evaluation Report. As requested, additional recommendations are presented below pertaining to the following items: (1) design infiltration rate for the stormwater infiltration facilities, (2) seepage bed foundation setback, and (3) concrete pavement design for parking areas and trash enclosure slabs. Design Infiltration Rates Test pit explorations for the referenced Geotechnical Evaluation report were conducted in October of 2017. An additional of four test pits were conducted in February of 2019 for the design infiltration rates of stormwater infiltration facilities. Three additional percolation tests and four temporary groundwater monitors were installed in the most recent test pits. Depth bottoms of infiltration swales were provided by T -O Engineers. Infiltration rate results and groundwater depths can be found in Appendix C. Seepage Bed Foundation Setback Structural foundations should be designed with a minimum horizontal separation of 25 feet from seepage beds or other storm water infiltration facilities to mitigate the migration of storm drainage into buildings and potential structural foundation damage. Concrete Pavement Section The Portland Cement Concrete (PCC) pavement sections presented below are based on an R -value of 22, assumed traffic index(s), a load safety factor of 1. 1, a modulus of rupture of 600 psi, and the guidelines presented in the latest revision to the Portland Cement Association, "Portland Cement Concrete Pavement Design for Light, Medium & Heavy Traffic (1991)". These preliminary pavement sections are presented for planning purposes only and should be verified based on specific laboratory testing performed subsequent to rough grading of the site. GEOTECHNICAL I ENVIRONMENTAL I MATERIALS ENTRATA FARMS LAND DEVELOPMENT PARTNERS, LLC PROJECT NO. 1905-ID3 MARCH 18, 2019 PAGE 2 The following criteria for the Portland Cement Concrete pavement should also be incorporated into preliminary site design of parking areas and trash enclosure slabs. No traffic should be allowed upon the newly poured concrete slabs for a minimum of 7 days after pouring. This time period is critical as it gives the concrete time to cure and gain strength. Perimeter edges of the concrete should be thickened, as appropriate. Longitudinal and transverse joints should be utilized to control cracking. Longitudinal and transverse control joints should be placed on approximately I I to 15 foot centers. These control joints can be constructed by using expansion joint material and pouring each section separately or by saw cutting the slabs to a minimum depth of one-fourth the slab thickness. Other methods for appropriately providing control joints may also be utilized. All joints should be properly sealed. All concrete should be designed, mixed, placed, finished, and cured in accordance with the guidelines presented by the Portland Cement Association (PCA), the American Concrete Institute (ACI) and the International Building Code (IBC). Concrete Pavement Sections ASSUMED TRAFFIC RIGHT -OF -AWAY SUBGRADE R -VALUE MINIMUM CONCRETE THICKNESS MINIMUM AGGREGATE THICKNESS in.) Aggregate Subbase* Base* (3/4" (Uncrushed (in.) minus) Aggregate) Parking and Trash Enclosure 22 7.0 6.0 11.0 No Truck Access TI = 6.0 *Aggregate Base and Subbase gradation specification requirement per the current edition of the Idaho Standards for Public Works Construction (ISPWC) Manual. Materials shall be placed in accordance with ISPWC Standard Specifications for Highway Construction. The recommendations contained in the referenced report that are not superseded by the recommendations presented herein, should be properly incorporated into continued development of the site. The recommendations presented herein should be incorporated into the grading construction phases of development. The engineering analyses performed concerning site preparation and the recommendations presented below, have been completed using the information provided to us regarding site development. In the event that the information concerning proposed development is not correct, the conclusion and recommendations contained in this report shall not be considered valid unless the changes are reviewed, and conclusions of this report are modified or approved in writing by this office. ENTRATA FARMS MARCH 18, 2019 LAND DEVELOPMENT PARTNERS, LLC PAGE 3 PROJECT NO. 1905-ID3 LIMITATIONS The materials encountered on the project site and utilized in our laboratory study are believed representative of the area; however, soil materials vary in character between excavations and conditions exposed during mass grading. Site conditions may vary due to seasonal changes or other factors. GeoTek, Inc. assumes no responsibility or liability for work, testing, or recommendations performed or provided by others. Since our study is based upon the site materials observed, selective laboratory testing and engineering analysis, the conclusions and recommendations are professional opinions. These opinions have been derived in accordance with current standards of practice and no warranty is expressed or implied. Standards of practice are subject to change with time. The opportunity to be of service is greatly appreciated. If you have any questions concerning this report or if we may be of further assistance, please do not hesitate to contact the undersigned. Respectfully submitted, GeoTek, Inc. Tyler S. Lydeen, EI Staff Professional GeoTek, Inc. �%ONAL p- STER�oQiy a 10884 t.��4 : David C. Waite, PE Branch Manager - Senior Engineer TEST PIT LOG GENERAL NOTES CONSISTENCY OF FINE-GRAINED SOILS Unconfined Compressive Strength, Qu, psf Standard Penetration or N- Value (SS) Blows/Ft Consistency < 500 <2 Very Soft 500-1,000 2 - 3 Soft 1,001 - 2,000 4 - 7 Firm 2,001 - 4,000 8-16 Stiff 4,001 - 8,000 17-32 Very Stiff > 8,001 32+ Hard RELATIVE DENSITY OF COARSE-GRAINED SOILS Standard Penetration (SPT) or N -Value (SS) Blows/Ft Relative Density 0 - 3 Very Loose 4 - 9 Loose 10-29 Medium Dense 30-49 Dense 50+ Very Dense SPT penetration test using 140 pound hammer, with 30 inch free fall on 2 inch outside diameter(1-3/8 ID) sampler For ring sampler using 140 Ib hammer, with a 30 inch free fall on 3 inch outside diameter (2-1/2 ID) sample, use N -value x 0.7 to get Standard N -value For fine grained soil consistency, thumb penetration used per ASTM D-2488 RELATIVE PROPORTIONS OF SAND AND GRAVEL. Descriptive Term of other constituents Percent of Dry Weight Trace < 15 With 15-29 Modifier > 30 GRAIN SIZE TERMINOLOGY Major Component of Sample Particle Size Boulders Over 12 inches Cobbles 3 inches to 12 inches Gravel #4 Sieve to 3 inches Sand #200 Sieve to #4 Sieve Silt or Clay Passing #200 Sieve RELATIVE HARDNESS OF CEMENTED SOILS (CALICHE) Description General Characteristics Very Dense to Moderately Hard Partially Cemented Granular Soil - Can be carved with a knife and broken with force by hand. Very Stiff to Moderately Hard Partially Cemented Fine -Grained Soil - Can be carved with a knife and broken with force by hand. Moderately Hard Moderate hammer blow required to break a sample Hard Heavy hammer blow required to break a sample Very Hard Repeated heavy hammer blow required to break a sample LOG LEGEND SAMPLING MATERIAL DESCRIPTION Soil Pattern USCS Symbol USCS Classification VL FILL Artificial Fill Soft GP or GW Poorly/Well graded GRAVEL L GM Silty GRAVEL Firm GC Clayey GRAVEL MD GP -GM or GW -GM Poorly/Well graded GRAVEL with Silt Stiff GP -GC or GW -GC Poorly/Well graded GRAVEL with Clay D SP or SW Poorly/Well graded SAND Very Stiff SM Silty SAND ®� w SC Clayey SAND SP -SM or SW -SM Poorly/Well graded SAND with Silt .�, AM ft 119 111� SP -SC or SW -SC Poorly/Well graded SAND with Clay SC -SM Silty Clayey SAND ML SILT MH Elastic SILT CL -ML Silty CLAY CL Lean CLAY CH Fat CLAY PCEM PARTIALLY CEMENTED CEM CEMENTED BDR BEDROCK SAMPLING Cohesionless _. SPT Ring Sample No Recovery Bulk Sample Water Table Cohesive Soils NR VL Very Loose CONSISTENCY Cohesionless Soils Cohesive Soils Cementation VL Very Loose So Soft MH Moderately Hard L Loose F Firm H Hard MD Medium Dense S Stiff VH Very Hard D Dense VS Very Stiff VD Very Dense TEST PIT L 0 G LOGGED BY: TL PROJECT #: 1905-I D3 METHOD: Backhoe PROJECT: Franklin and Ten Mile EXCAVATOR: Just Dig It CLIENT: T -O Engineers, Inc DATE: 10/9/17 G G 0 T E K LOCATION: Franklin Rd and Ten Mile Rd ELEVATION: SAMPLES � p T (0 zE TEST PIT NUMBER: TP -1 C y REMARKS a� o v o v MATERIAL DESCRIPTION AND COMMENTS ML Brown Sandy SILT w/ Organics; Slightly Moist So 1 ML Tan Sandy SILT; Slightly Moist F 2 3 4 Percolation Test Installed at 4.0' SP Tan Poorly Graded SAND; Slightly Moist to Moist MD - 5 D 6 7 8 9 ML Brown SILT w/ Varying amounts of Sand Content; Moist to S Saturated 10 11 12 Ground Water Measured at 13.2' per measurement 13 10/24/2017 14 END OF TEST PIT @ 14.5' 15 Groundwater Encountered 16- 16 17- 17 18 19 20 320 E. Corporate Drive, Suite 300, Meridian, Idaho 83642 (208) 888-7010 Fax: (208) 888-7924 TEST PIT L 0 G 320 LOGGED BY: TL PROJECT #: 1905-ID3 METHOD: Backhoe PROJECT: Franklin and Ten Mile EXCAVATOR: Just Dig It CLIENT: T -O Engineers, Inc DATE: 10/9/17 G E 0 T E K LOCATION: Franklin Rd and Ten Mile Rd ELEVATION: SAMPLES c T y TEST PIT NUMBER: TP -2 N_ a REMARKS O C O H m fn f% MATERIAL DESCRIPTION AND COMMENTS ML Dark Brown SILT w/ Organics; Moist So 1 ML Dark Brown SILT; Moist F 2 CL -ML Grey Sandy Silty CLAY w/ Some Gravel; Moist S 3 Xat Ground Water Measured 4 3.8' per measurement 10/24/2017 5 6 SM Brown Silty SAND w/ Gravel; Moist to Saturated D 7 8 , 9 10 R; � 11 ' 12 END OF TEST PIT @ 11.5' Groundwater Encountered 13- 314151617181920 14- 15- 16- 17- 18- 19- 20- 320 E. Corporate Drive, Suite 300, Meridian, Idaho 83642 (208) 888-7010 Fax: (208) 888-7924 TEST PIT L 0 G LOGGED BY: TL PROJECT #: 1905-ID3 METHOD: Backhoe PROJECT: Franklin and Ten Mile EXCAVATOR: Just Dig It CLIENT: T -O Engineers, Inc DATE: 10/9/17 G E 0 T E K LOCATION: Franklin Rd and Ten Mile Rd ELEVATION: SAMPLES c �, E TEST PIT NUMBER: TP -3 REMARKS O. D o. EO H O <n m N MATERIAL DESCRIPTION AND COMMENTS ML Tan Sandy SILT w/ Organics; Slightly Moist So 1 ML Tan Sandy SILT; Slightly Moist F 2 SP Brown Poorly Graded SAND; Slightly Moist D 3 4 5 SM Brown Silty SAND; Moist D 6 SP Brown Poorly Graded Fine SAND; Moist to Saturated D 7 8 9 ML Brown SILT w/ Sand; Saturated S 10 11 — END OF TEST cm 11.0' Groundwater Encountered 12 13 14 15 16 17 18 19 20 320 E. Corporate Drive, Suite 300, Meridian, Idaho 83642 (208) 888-7010 Fax: (208) 888-7924 TEST PIT LOG LOGGED BY: TL PROJECT R: 1905-ID3 METHOD: Backhoe PROJECT: Franklin and Ten Mile EXCAVATOR: Just Dig It CLIENT: T -O Engineers, Inc DATE: 10/9/17 G E O T E K LOCATION: Franklin Rd and Ten Mile Rd ELEVATION: SAMPLES 0 y c a y TEST PIT NUMBER: TP -4 v 1 d N REMARKS E v, m O MATERIAL DESCRIPTION AND COMMENTS ML Brown Sandy SILT w/ Organics; Slightly Moist o 1 ML Brown Sandy SILT; Slightly Moist F SP -SM Tan Poorly Graded SAND w/ Silt and Some Partially MD - 3 -• Cemented Layers; Slightly Moist D s �. 4 e s a 6 s 6 ML Brown SILT w/ Sand and some Partially Cemented Layers S 7 and Fine Sand; Moist 8- 9 SP Brown Poorly Graded SAND w/ Some Silt; Moist D 10- I ML Brown Sandy SILT; Moist S 12- 213END 13- ENDOF TEST PIT @ 14.0' 15 Groundwater Encountered 16- 8171819 17- 18- 19 20 320 E. Corporate Drive, Suite 300, Meridian, Idaho 83642 (208) 888-7010 Fax: (208) 888-7924 TEST PIT LOG LOGGED BY: TL PROJECT #: 1905-ID3 METHOD: Backhoe A23r... PROJECT: Franklin and Ten Mile EXCAVATOR: Just Dig It LIE NT: T-0 Engineers, Inc DATE: 10/9/17 G EOTE K LOCATION: Franklin Rd and Ten Mile Rd ELEVATION: LGEC SAMPLES >N TEST PIT NUMBER: TP -5 REMARKS = L MATERIAL DESCRIPTION AND COMMENTS ML Brown SILT w/ Organics; Slightly Moist So ML Brown SILT; Slightly Moist F SM Brown Silty SAND; Slightly Moist D 4 CEM Grey CEMENTED Sand; Slightly Moist H - VH SID Brown Poorly Graded SAND; Slightly Moist D Percolation Test installed at 7.5' SP Tan Poorly Graded Fine SAND D SM Tan SAND w/ Silt; Moist to Saturated D Groundwater Encountered 32UE.Corporate Drive, Suite 30O.Meridian, Idaho 83042 (208) 888-7010 Fax: C288\888'y924 TEST PIT L 0 G 320 LOGGED BY: TSL PROJECT#: 1905-ID3 METHOD: Trackhoe PROJECT: Entrata Farms EXCAVATOR: Lurre Const. CLIENT: Landmark oeveioomem Panaa� DATE: 2/26/19 G E O T E K LOCATION: Franklin Rd and Ten Mile Rd ELEVATION: SAMPLES e T o t E a a y TEST PIT NUMBER: TP -6 u 2REMARKS C d O y N y C n N U MATERIAL DESCRIPTION AND COMMENTS ML Dark Brown Sandy SILT; Moist So 1 SM Brown Silty SAND; Moist F 2 3 4 ML Dark Brown SILT w/ Sand; Moist F 5 6 SP Brown Poorly Graded SAND wl Slit: Moist D 7I Percolation Teat Contludetl at I SP 113rown Poorly Graded Sand Moist D 1.1 8 E O OF TEST PIT , 7.5' NO GROUNDWATER ENCOUNTERED 9 10 11 12- 2131415 13- 14- 15. 16- 617181920 17- 18- 19- 20- 320 E. Corporate Drive, Suite 300, Meridian, Idaho 83642 (208) 888-7010 Fax: (208) 888-7924 PIT L 0 G 320 ATEST LOGGED BY: TSL PROJECT #: 1905-ID3 METHOD: Trackhoe '.. PROJECT: Entrata Farms EXCAVATOR: Lurre Const. CLIENT: Landmark Development Partners DATE: 2/26/19 G E 0 T E K LOCATION: Franklin Rd and Ten Mile Rd ELEVATION: SAMPLES c T � C 170 � 4.1 E TEST PIT NUMBER: TP -7 H REMARKS D E cn C m O N = O y MATERIAL DESCRIPTION AND COMMENTS ML Dark Brown SILT w/ Organics; Moist So 1 ML Dark Brown SILT; Moist F 2 CL -ML Grey Sandy Silty CLAY w/ Some Gravel; Moist S 3 Ground Water Measured 4 at 5.6' per measurement 2/27/2019 5 6 SM Brown Silty SAND w/ Gravel; Moist to Saturated D 7 END OF TEST PIT @ 7.5' 8 Groundwater Encountered 9 10- 11 12- 21314151617181920 13- 14- 15- 16- 17- 18- 19- 20- 320 E. Corporate Drive, Suite 300, Meridian, Idaho 83642 (208) 888-7010 Fax: (208) 888-7924 TEST PIT L 0 G 320 LOGGED BY: TSL FAC� PROJECT #: 1905-ID3 METHOD: Trackhoe PROJECT: Entrata Farms EXCAVATOR: Lurre Const.— C LIE N T : Landmark Development Partners DATE: 2/26/19 E 0 T E K LOCATION: Franklin Rd and Ten Mile Rd ELEVATION: SAMPLES o CL n TEST PIT NUMBER: TP -8 v N REMARKS G. �+ O. N a. t/7 _ .N D E cn C m 0 (U O MATERIAL DESCRIPTION AND COMMENTS j ML Tan Sandy SILT w/ Gravel & Organics; Moist So 1 ` ML Tan Sandy SILT w/ Gravel; Moist F 2 f 3 I fk Ij 4 5 mI 6 SM Brown Silty SAND w/ Gravel; Moist D 7 Percolation Test Condicted at 7.5' END OF TEST PIT @ 7.5' 8 NO GROUNDWATER ENCOUNTERED 9 10- 11 12- 21314151617181920 13- 14- 15- 16- 17- 18- 19- 20- 320 E. Corporate Drive, Suite 300, Meridian, Idaho 83642 (208) 888-7010 Fax: (208) 888-7924 TEST PIT LOG 320 LOGGED BY: TSL PROJECT #: 1905-I D3 METHOD: Trackhoe PROJECT: Entrata Farms EXCAVATOR: Lurre Const. C LIE N T : Landmark Development Partners DATE: 2/26/19 G 0 T G K LOCATION: Franklin Rd and Ten Mile Rd ELEVATION: SAMPLES 6 7 TEST PIT NUMBER: TP -9 H REMARKS .� o E c O h o MATERIAL DESCRIPTION AND COMMENTS ML Tan Sandy SILT w/ Organics; Slightly Moist So 1 ML Tan Sandy SILT; Moist F 2 —jv' N k SM Lt. Brown Silty SAND w/ Gravel; Slightly Moist D 3 4 SP Tan Poorly Graded SAND w/ Gravel; Slightly Moist D 5 6 Percolation Test Conducted at 7.0' 7 END OF TEST PIT @ 7.0' NO GROUNDWATER ENCOUNTERED 8 9 10- 11 12- 21314151617181920 13- 14- 15- 16- 17- 18- 19- 20- 320 E. Corporate Drive, Suite 300, Meridian, Idaho 83642 (208) 888-7010 Fax: (208) 888-7924 EA,I;J;A:4 Z FIELD TESTS AND OBSERVATIONS (1905-I03) PERCOLATION TESTS The infiltration rate was determined by conducting percolation tests for onsite soils. The infiltration rate was determined in inches per hour in general accordance with Ada County requirements. Infiltration rate results are presented below. LOCATION INFILTRATION RATE (Inches/Hour) (P-1) TP -I @ 4.0' 2.2 (P-2) TP -5 @ 7.5' 24.0+ (P-3) TP -6 @ 7.5' 24.0+ (P-4) TP -8 @ 7.5' 1.68 (P-5) TP -9 @ 7.0' 24.0+ GROUND WATER MONITORING RESULTS Ground water monitoring results are presented below. Ground water elevation results are recorded in feet below existing grade. LOCATION GROUNDWATER ELEVATION TP -1 14.0'+ TP -2 5.6' TP -6 7.5'+ TP -7 5.2' TP -8 7.5'+ TP -9 7.0'+ + Indicates a dry reading at the bottom of the piezometer n/a Indicates that the piezometer was damaged/missing in the field and no measurements were obtained. Bold Indicates ground water was encountered in the piezometer Entrata Subdivision Phase 2 Drainage Calculations APPENDIX E L:\190121\40—Final Design\Stormwater\190121 Storm Drainage Report Phase 2.doc 1905-ID3 Entrata Farms TP- I TP -2 TP -6 TP -7 TP -8 TP -9 10/25/17 13.2' 3.8- .s'3/27/18 3/27/18 14.0'+ 5.4' 4/16/18 14.0'+ 5.3' 5/4/18 14.0'+ 5.8' 5/15/18 13.9' 4.2' 5/30/18 13.7' 3.9' 6/11/18 13.2' 3.9' 6/25/18 10.7' 3.5' 719/18 11.8' 3.1' 7/23/18 11.5' 2.7' 8/6/18 11.3' 2.4- .4'8/27/18 8/27/18 9.9' 2.3' 9/14/18 11.5' 2.8' 10/3/18 12.0' 2.9' 10/17/18 13.0' 5.5' 11/1/18 13.6' 4.0' 2/27/19 14.0'+ 5.6' 7.5'+ 5.2' 7.5'+ 7.0'+ 4/1/19 14.0'+ 5.8' 7.5'+ 5.9' 7.5'+ 7.0'+ 512/19 14.0'+ 5.4' 7.5'+ 5.5' 7.5'+ 7.0'+ A. • , r Er . -- W Franklin Road + APPROXIMATETEST PIT LOCATIONS Source: Google Earth 2017, GeoTelc Field Observations, 2017. Not to Scale FIGURE 2 SITE EXPLORATION PLAN Entrata Farms Meridian, Idaho G E a T E K Prepared for: Landmark Development Partners, LLC GEOTECHNICAL I ENVIRONMENTAL I MATERIALS Project No,: Report Date: Drawn By: 320 E. Corporate Dr, Suite 300, Meridian, ID 83642 1905-03 May 2019 TSL (208) 888-7010 (phone)/(208) 888-7924 (FAX)