The URL can be used to link to this page

Home My WebLink AboutSDP 16-07; OLIVENHAIN MUNICIPAL WATER DISTTICT; GEOTECHNICAL INVESTIGATION; 2016-03-03SCST, Inc. Z Corporate Headquarters 6280 Piverclale Street Lu San Diego, CA 92120 Z p 619.280.4321 Ii T 877.215.4321 Z F 619.280.4717 w W www.scst.com SDVOSB. DYBE GEOTECHNICAL INVESTIGATION OLIVENHAIN MUNICIPAL WATER DISTRICT (OMWD) BUILDING D 1966 OLIVENHAIN ROAD ENCINITAS, CALIFORNIA MR. DAVID PADILLA, P.E. INFRASTRUCTURE ENGINEERING CORPORATION 14271 DANIELSON STREET POWAY, CALIFORNIA 92064 PREPARED BY: SCST, INC. 6280 RIVERDALE STREET SAN DIEGO, CALIFORNIA 92120 1 r4 APR 112017 Providing Professional Engineering Services Since 1.959 EvELOPME\T Lee Thomas B. Canady, Principal Engineer IBC:WLV:ER:aw W. LEE \ vAt4flERHURST \1' NO. '11125 r CERIWIED J' ENGINEERING I GEOLOGIST I_ to LU LU z z LU SCST, Inc. Corporate Headquarters 6280 Piverclale Street San Diego, CA 92120 P 619.280.4321 T 877.215.4321 619.280.4717 W www.scst.com SDVOSB.DVBE March 3, 2016 SCST No. 160105P3 Report No. I David Padilla, P.E. Project Manager Infrastructure Engineering Corporation 14271 Danielson Street Poway, California 92064 Subject: GEOTECHN ICAL INVESTIGATION OLIVENHAIN MUNICIPAL WATER DISTRICT (OMWD) BUILDING D 1966 OLIVENHAIN ROAD ENCINITAS, CALIFORNIA Dear Dave: SCSI, Inc. is pleased to present our report describing the geotechnical investigation performed for the subject project. We conducted the geotechnical investigation in general conformance with the scope of work presented in our proposal dated August 18, 2015. If you have any questions, please call us at (619) 280-4321. Respectfully submitted, SCST, INC. (1) Addressee via e-mail at dpadilIaiecorporation.com TABLE OF CONTENTS SECTION PAGE EXECUTIVE SUMMARY ............................................................................................................. INTRODUCTION ............................................................................................................ I SCOPE OF WORK ......................................................................................................... I 2.1 FIELD INVESTIGATION ................................................................................................. I 2.2 LABORATORY TESTING ..............................................................................................I 2.3 PERCOLATION TESTING .............................................................................................I 2.4 ANALYSIS AND REPORT .............................................................................................I SITE DESCRIPTION......................................................................................................2 PROPOSED DEVELOPMENT.......................................................................................2 S. GEOLOGY AND SUBSURFACE CONDITIONS............................................................2 GEOLOGIC HAZARDS..................................................................................................3 6.1 FAULTING AND SURFACE RUPTURE.........................................................................3 6.2 CBC SEISMIC DESIGN PARAMETERS........................................................................3 6.3 LIQUEFACTION, DYNAMIC SETTLEMENT AND LATERAL SPREADING ...................3 6.4 LANDSLIDES AND SLOPE STABILITY.........................................................................4 6.5 TSUNAMIS, SEICHES AND FLOODING .......................................................................4 6.6 SUBSIDENCE................................................................................................................4 6.7 HYDRO-CONSOLIDATION ............................................................................................ 4 CONCLUSIONS.............................................................................................................4 RECOMMENDATIONS..................................................................................................5 8.1 SITE PREPARATION AND GRADING...........................................................................5 8.1.1 Site Preparation.....................................................................................................5 8.1.2 Remedial Grading - Building Areas........................................................................5 8.1.3 Remedial Grading - Pavement and Exterior Slab Areas ........................................6 8.1.4 Compacted Fill.......................................................................................................6 8.1.5 Imported Soil .........................................................................................................6 8.1.6 Expansive Soil.......................................................................................................6 8.1.7 Temporary Excavations.........................................................................................7 8.1.8 Temporary Shoring................................................................................................7 8.1.9 Slopes...................................................................................................................7 8. 1.10 Site Excavation Characteristics............................................................................8 8.1.11 Surface Drainage.................................................................................................8 8.1.12 Grading Plan Review...........................................................................................8 8.2 FOUNDATIONS.............................................................................................................8 8.2.1 Mat Foundations....................................................................................................8 8.2.2 Resistance to Lateral Loads ..................................................................................8 8.2.3 Settlement Characteristics.....................................................................................9 8.2.4 Moisture Protection................................................................................................9 8.2.5 Foundation Plan Review........................................................................................9 8.2.6 Foundation Excavation Observations ....................................................................9 8.3 EXTERIOR SLABS-ON-GRADE ....................................................................................9 8.4 CONVENTIONAL RETAINING WALLS.........................................................................10 'It Nil TABLE OF CONTENTS (Continued) SECTION PAGE 8.4.1 Foundations..........................................................................................................10 8.4.2 Lateral Earth Pressures........................................................................................10 8.4.3 Seismic Earth Pressure........................................................................................11 8.4.4 Backfill..................................................................................................................11 8.5 MECHANICALLY STABILIZED EARTH RETAINING WALLS.......................................11 8.6 PIPELINES....................................................................................................................12 8.6.1 Thrust Blocks........................................................................................................12 8.6.2 Modulus of Soil Reaction......................................................................................12 8.6.3 Pipe Bedding........................................................................................................12 8.7 PAVEMENT SECTION RECOMMENDATIONS............................................................12 8.8 PERVIOUS PAVEMENT SECTION RECOMMENDATIONS.........................................13 8.9 SOIL CORROSIVITY ....................................................................................................14 8.10 INFILTRATION............................................................................................................14 GEOTECHNICAL ENGINEERING DURING CONSTRUCTION....................................14 CLOSURE ..................................................................................................................... 15 REFERENCES..............................................................................................................15 ATTACHMENTS ;11411: 1* Figure1.............................................................................................................Site Vicinity Map Figure2..................................................................................................USGS Quadrangle Map Figure 3...........................................................................................Subsurface Exploration Map Figure 4....................................................................................Regional Geology and Fault Map Figure 5..........................................................................Typical Retaining Wall Backdrain Detail Figure 6.................................................................Typical MSE Retaining Wall Backdrain Detail APPENDICES AppendixI.......................................................................................................Field Investigation Appendix II ..................................................................................................... Laboratory Testing Appendix III .................................................................................... Borehole Percolation Testing EXECUTIVE SUMMARY This report presents the results of the geotechnical investigation SCSI performed for the subject project. We understand that the project will consist of the design and construction of a one-story building, pavements and storm water retention basins. The purpose of our work is to provide conclusions and recommendations regarding the geotechnical aspects of the project. SCSI explored the subsurface conditions by drilling four borings and four percolation test holes to depths between about 5 and 391/2 feet below the existing ground surface. Kleinfelder (2001) previously drilled one boring to a depth of about 331/2 feet below the existing ground surface in the area of the planned building. An SCST engineer logged the current borings and test holes and collected samples of the materials encountered for laboratory testing. SCST tested selected samples from the borings to evaluate pertinent soil classification and engineering properties to assist in developing geotechnical conclusions and recommendations. The materials encountered in the borings and percolation test holes consist of young alluvial flood plain deposits underlain by Santiago Formation. The alluvial deposits consist of loose to dense silty to clayey sand and very stiff sandy fat clay. The Santiago Formation consists of dense to very dense, weakly cemented silty to clayey sandstone and hard claystone. Groundwater was encountered in borings B-I through B-3 at depths between about II 1/2 and 15 feet below the existing ground surface. SCSI performed four borehole percolation tests. The test results indicate infiltration rates between <0.1 inch per hour and about 3.8 inches per hour. The infiltration rate of the actual soils that will be encountered at the bottom of storm water retention basins could vary significantly subsequent to grading. The main geotechnical consideration affecting the planned development is the presence of potentially compressible and potentially liquefiable alluvium. Existing fill, if encountered, should be excavated in its entirety. In building areas, we recommend that alluvium within 5 feet of existing or planned grade, whichever is deeper, be excavated and replaced as compacted fill. In exterior slab areas, we recommend that alluvium within 2 feet of planned subgrade be excavated and replaced as compacted fill. We expect that most of the onsite soils can be reused as compacted fill. If the recommended remedial grading is performed, seismic settlements beneath planned Building 0 are estimated to be about 2 inches total and 1 inch differential across the structure. If the soils beneath the site liquefy, lateral spreading on the order of 3 feet could occur. Based on the type of construction, we recommend that the planned building be supported on a reinforced concrete mat foundation underlain by a geogrid-reinforced compacted fill mat. The mat foundation and exterior concrete slabs-on-grade should be underlain by at least 2 feet of material with an expansion index of 20 or less. We anticipate that most of the onsite soils will meet the expansion index criteria. If the estimated settlements are deemed not tolerable by the project structural engineer, then ground improvement, deep foundations, or other alternatives should be considered. The grading and foundation recommendations presented herein may need to be updated once final plans are developed. 'It MHz. INTRODUCTION This report presents the results of the geotechnical investigation SCSI performed for the subject project. We understand that the project will consist of the design and construction of a one-story building, pavements and storm water retention basins. The purpose of our work is to provide conclusions and recommendations regarding the geotechnical aspects of the project. Figure 1 presents a site vicinity map. Figure 2 presents the site location on a United States Geologic Survey 7.5 Minute Quadrangle Map. SCOPE OF WORK 2.1 FIELD INVESTIGATION SCST explored the subsurface conditions by drilling four borings and four percolation test holes to depths between about 5 and 39V2 feet below the existing ground surface using a truck-mounted drill rig equipped with a hollow stem auger. Kleinfelder (2001) previously drilled one boring to a depth of about 33Y2 feet below the existing ground surface in the area of the planned building using a truck-mounted drill rig equipped with a hollow stem auger. Figure 3 shows the approximate locations of the borings and percolation test holes. An SCST engineer logged the current borings and percolation test holes and collected samples of the materials encountered for laboratory testing. Appendix I presents logs of the borings and the percolation test holes. Soils are classified according to the Unified Soil Classification System illustrated on Figure I-I. 2.2 LABORATORY TESTING Selected samples were tested to evaluate pertinent soil classification and engineering properties and enable development of geotechnical conclusions and recommendations. The laboratory tests consisted of in situ moisture and density, grain size distribution, Atterberg Limits, R-value, expansion index, fines content and corrosivity. Appendix II presents the results of the laboratory tests and brief explanations of the test procedures. 2.3 PERCOLATION TESTING We performed four borehole percolation tests. Appendix III presents the results of the tests. 2.4 ANALYSIS AND REPORT The results of the field and laboratory tests were evaluated to develop conclusions and recommendations regarding: Subsurface conditions beneath the site Potential geologic hazards, including liquefaction Criteria for seismic design in accordance with the 2013 California Building Code (CBC) Site preparation and grading Appropriate alternatives for foundation support along with geotechnical engineering criteria for design of the foundations Estimated foundation settlements Support for concrete slabs-on-grade Infrastructure Engineering Corporation March 3, 2016 OMWD Building D SCST No. 160105P3-1 Encinitas, California Page 2 Lateral pressures for the design of retaining walls Pavement sections Corrosion potential Infiltration rate SITE DESCRIPTION The site is located within existing OMWD headquarters at 1966 Olivenhain Road in the City of Encinitas, California. The site is located on the northern flank of the Encinitas Creek drainage basin. Encinitas Creek flows in an east-west direction about 600 feet south of the site. The site is occupied by various buildings, hardscape and landscape areas, and pavements for site access and parking. Site elevations range from about 121 feet at the northwestern portion of the site to about 115 feet at the southeastern portion of the site. PROPOSED DEVELOPMENT We understand the proposed development will consist of a one-story building, pavements and storm water retention basins. As currently planned, the Building D will have a finished floor elevation of 122.12 feet. Minor grading with cuts and fills less than 5 feet deep will be required to achieve finished site elevations. GEOLOGY AND SUBSURFACE CONDITIONS The site is located within the Peninsular Ranges Geomorphic Province of California, which stretches from the Los Angeles basin to the tip of Baja California. This province is characterized as a series of northwest trending mountain ranges separated by subparallel fault zones, and a coastal plain of subdued Iandforms. The mountain ranges are underlain primarily by Mesozoic metamorphic rocks that were intruded by plutonic rocks of the southern California batholith, while the coastal plain is underlain by subsequently deposited marine and non-marine sedimentary formations. The site is located in the coastal plain portion of the province and is underlain by young alluvial flood plain deposits and Santiago Formation. Descriptions of the materials are presented below. Figure 4 presents the regional geology in the vicinity of the site. Young Alluvial Flood Plain Deposits (Ova): The alluvial deposits consist of loose to dense silty to clayey sand and very stiff sandy fat clay. The alluvium encountered in the borings extends to depths between about 25 and 38 feet below the existing ground surface. Santiago Formation (Tsa: The Santiago Formation underlies the alluvium. The Santiago Formation materials consists of dense to very dense, weakly cemented silty to clayey sandstone and hard claystone. Groundwater - Groundwater was encountered in borings B-I through B-3 at depths between about I1Y2 and 15 feet below the existing ground surface. Groundwater levels may fluctuate in the future due to rainfall, irrigation, broken pipes, or changes in site drainage. NEW NIL Infrastructure Engineering Corporation March 3, 2016 OMWD Building D SCST No. 160105P3-1 Encinitas, California Page 3 6. GEOLOGIC HAZARDS 6.1 FAULTING AND SURFACE RUPTURE The closest known active fault is the Rose Canyon fault zone (Del Mar section) located about 6 miles west of the site (Figure 4) capable of producing a 7.2 moment magnitude earthquake. The site is not located in an Alquist-Priolo Earthquake Fault Zone. No active faults are known to underlie or project toward the site. Therefore, the probability of fault rupture is low. 6.2 CBC SEISMIC DESIGN PARAMETERS A geologic hazard likely to affect the project is groundshaking as a result of movement along an active fault zone in the vicinity of the subject site. The site coefficients and adjusted maximum considered earthquake spectral response accelerations in accordance with the 2013 CBC are presented below: Site Coordinates: Latitude 33.067760 Longitude -117.24652° Site Class: D Site Coefficients, Fa = 1.080 F= 1.594 Mapped Spectral Response Acceleration at Short Period, S = 1.051g Mapped Spectral Response Acceleration at 1-Second Period, S1 = 0.406g Design Spectral Acceleration at Short Period, SDs = 0.756g Design Spectral Acceleration at 1-Second Period, S01 = 0.431g Site Peak Ground Acceleration, PGAM = 0.448g 6.3 LIQUEFACTION, DYNAMIC SETTLEMENT AND LATERAL SPREADING Liquefaction is a process in which soil grains in a saturated deposit lose contact after the occurrence of earthquakes or other sources of ground shaking. The soil deposit temporarily behaves as a viscous fluid; pore pressures rise, and the strength of the deposit is greatly diminished. Liquefiable soils typically consist of cohesionless sands and silts that are loose to medium dense, and saturated. Recent studies also show that some relatively soft cohesive soils can be subject to cyclic softening during significant earthquake shaking. To liquefy, saturated soils must be subjected to ground shaking of sufficient magnitude and duration. For our analysis we used a PGA of 0.448g, an earthquake magnitude of 7.2 and a groundwater depth of 10 feet. Based on our analysis, there is a potential for liquefaction to occur within the loose to medium dense alluvial sands underlying the site. Dynamic and post-liquefaction settlements beneath Building D are estimated to be about 3 inches total and 11/2 inches differential across the structure. We also performed the analysis assuming that the top 5 feet of soil would be over-excavated and recompacted. Based on this analysis, the settlements are estimated to be about 2 inches total beneath Building D and 1 inches differential across the structure. Based on our analysis, the site is also susceptible to lateral spreading. If the soils beneath the site liquefy, lateral spreading on the order of 3 feet could occur. Infrastructure Engineering Corporation March 3, 2016 OMWD Bulldinq D SCST No. 160105P3-1 Page 4 6.4 LANDSLIDES AND SLOPE STABILITY Evidence of landslides or slope instabilities was not observed. The potential for landslides or slope instabilities to occur at the site is considered negligible. 6.5 TSUNAMIS, SEICHES AND FLOODING The site is not located within a mapped area on the State of California Tsunami Inundation Maps (Cal EMA, 2009); therefore, damage due to tsunamis is considered negligible. Seiches are periodic oscillations in large bodies of water such as lakes, harbors, bays, or reservoirs. The site is not located adjacent to any lakes or confined bodies of water; therefore, the potential for a seiche to affect the site is negligible. Portions of the site are located within a mapped 100-year floodplain (County of San Diego, 2012). We understand that fill will be placed to elevate Building D about 2 feet above the mapped 100-year floodplain. 6.6 SUBSIDENCE The site, is not located in an area of known subsidence associated with fluid withdrawal (groundwater or petroleum); therefore, the potential for subsidence due to the extraction of fluids is low. 6.7 Hydro-consolidation can occur in recently deposited (less than 10,000 years old) sediments that were deposited in a semi-arid environment. Examples of such sediments are aolian sands, alluvial fan deposits, and mudflow sediments deposited during flash floods. The pore space between particle grains can re-adjust when inundated by groundwater causing the material to consolidate. The upper alluvial deposits are susceptible to hydra-consolidation. The recommended remedial grading of the upper soils should effectively mitigate this hazard. 7. CONCLUSIONS The main geotechnical consideration affecting the planned development is the presence of potentially compressible and potentially liquefiable alluvium. The loose alluvial soils that cover the site are potentially compressible and susceptible to settlement from static structural or fill loads. They are also susceptible to dynamic settlement under seismic loading. The saturated alluvium is potentially liquefiable and susceptible to post-liquefaction settlement. If the recommended remedial grading of the upper soils is performed, we estimate that dynamic and post-liquefaction settlements will be about 2 inches total and 1 inch differential beneath Building D. If the soils beneath the site liquefy, lateral spreading on the order of 3 feet could occur. To reduce the liquefaction hazard, either the soils can be densified through ground improvement or the effects of liquefaction can be reduced through a combination of remedial grading and structural mitigation. If selected, various ground improvement methods, including compaction grouting, deep sail mixing, or jet grouting, could be used at the site to mitigate the liquefiable soils Infrastructure Engineering Corporation March 3, 2016 OMWD Building D SCST No. 160105P3-1 Encinitas, California Page 5 and reduce settlements. If ground improvement is used, verification testing should be performed upon completion to confirm that the liquefiable soils have been sufficiently densified. For relatively small, lightweight structures such as the planned building, the cost of ground improvement may not be practical if the effects of potential liquefaction can be reduced by constructing a geogrid-reinforced compacted fill mat and a rigid reinforced concrete mat foundation. The grading and foundation recommendations presented in this report assume that the effects of the estimated seismic settlements can be sufficiently reduced by remedial grading and by structural design. If the estimated settlements are deemed not tolerable by the structural engineer, then ground improvement, deep foundations or other alternatives should be considered. 8. RECOMMENDATIONS 8.1 SITE PREPARATION AND GRADING 8.1.1 Site Preparation Site preparation should begin with the removal of existing improvements, vegetation and debris. Subsurface improvements that are to be abandoned should be removed, and the resulting excavations should be backfilled and compacted in accordance with the recommendations of this report. Pipeline abandonment can consist of capping or rerouting at the project perimeter and removal within the project perimeter. If appropriate, abandoned pipelines can be filled with grout or slurry as recommended by and observed by the geotechnical consultant. 8.1.2 Remedial Grading - Building Areas We recommend that remedial grading be performed beneath the planned building to improve structural support and reduce the effects of static and seismic settlements. Existing fill, if encountered, should be excavated in its entirety. Alluvium within 5 feet of existing or planned grade, whichever is deeper, should be excavated. Horizontally, the bottom of excavation should extend at least 5 feet outside planned perimeter foundations or up to existing improvements, whichever is less. Prior to placing fill, we recommend placing a layer of Tensar TX5 or equivalent reinforcing geogrid at the base of the excavation. The geogrid layer should extend at least 3 feet beyond the edge of the foundation. An SCST representative should observe conditions exposed in the bottom of excavations to determine if additional excavation is required. If the base of the excavation is wet and yielding, it can be stabilized by placing a layer of %-inch crushed rock over the geogrid. A minimum 1-foot thick layer rock is typically needed. Prior to placing compacted fill, a layer of nonwoven filter fabric (Mirafi 140N or equivalent) should be placed above the crushed rock to prevent fines from washing into the voids of the %-inch crushed gravel, which could result in post construction settlement. Infrastructure Engineering Corporation March 3, 2016 OMWD Building D SCST No. 160105P3-1 Encinitas, California Page 6 8.1.3 Remedial Grading - Pavement and Exterior Slab Areas Existing fill, if encountered, should be excavated in its entirety. Alluvium should be excavated to a depth of 2 feet below finished subgrade elevation. Horizontally, the excavations should extend at least 2 feet outside the perimeter of the planned improvement or up to existing improvements, whichever is less. An SCSI representative should observe conditions exposed in the bottom of the excavation to determine if additional excavation is required. 8.1.4 Compacted Fill Prior to placing geogrid or fill, the exposed surface at the bottom of excavation should be scarified to a depth of 12 inches, moisture conditioned to near optimum moisture content and compacted to at least 90% relative compaction. Material with an expansion index of 20 or less determined in accordance with ASTM D4829 should be used from 2 feet below the deepest planned foundation bottom level to finished pad grade elevation. Exterior concrete slabs-on-grade should be underlain by at least 2 feet of material with an expansion index of 20 or less. We expect that most of the excavated soils will meet the expansion index criteria and can be reused as compacted fill. Excavated material, except for roots, debris and rocks greater than 6 inches, can be used as compacted fill. Fill should be moisture conditioned to near optimum moisture content and compacted to at least 90% relative compaction. Fill should be placed in horizontal lifts at a thickness appropriate for the equipment spreading, mixing, and compacting the material, but generally should not exceed 8 inches in loose thickness. The maximum dry density and optimum moisture content for the evaluation of relative compaction should be determined in accordance with ASTM D1557. Utility trench backfill beneath structures, pavements and slabs-on-grade should be compacted to at least 90% relative compaction. The top 12 inches of subgrade beneath pavements should be compacted to at least 95% relative compaction. 8.1.5 Imported Soil Imported soil should consist of predominately granular soil free of organic matter and rocks greater than 6 inches. Imported soil should have an expansion index of 20 or less and should be inspected and, if appropriate, tested by SCSI prior to transport to the site. 8.1.6 Expansive Soil The onsite soils tested have a very low expansion potential. The recommendations presented in this report reflect a very low expansion potential. Infrastructure Engineering Corporation March 3, 2016 OMWD Building D SCST No. 160105P3-1 Encinitas, California Page 7 8.1.7 Temporary Excavations Temporary excavations 3 feet deep or less can be made vertically. Deeper temporary excavations should be laid back no steeper than 1:1 (horizontal:vertical). The faces of temporary slopes should be inspected daily by the contractor's Competent Person before personnel are allowed to enter the excavation. Any zones of potential instability, sloughing or raveling should be brought to the attention of the Engineer and corrective action implemented before personnel begin working in the excavation. Excavated soils should not be stockpiled behind temporary excavations within a distance equal to the depth of the excavation. SCST should be notified if other surcharge loads are anticipated so that lateral load criteria can be developed for the specific situation. If temporary slopes are to be maintained during the rainy season, berms are recommended along the tops of slopes to prevent runoff water from entering the excavation and eroding the slope faces. Slopes steeper than those described above will require shoring. Additionally, temporary excavations that extend below a plane inclined at 1/2:1 (horizontal:vertical) downward from the outside bottom edge of existing structures or improvements will require shoring. A shoring system consisting of soldier piles and lagging can be used. 8.1.8 Temporary Shoring For design of cantilevered shoring, an active soil pressure equal to a fluid weighing 35 pcf can be used for level retained ground or 55 pcf for 2:1 (horizontal:vertical) sloping ground. The surcharge loads on shoring from traffic and construction equipment adjacent to the excavation can be modeled by assuming an additional 2 feet of soil behind the shoring. For design of soldier piles, an allowable passive pressure of 350 psf per foot of embedment over three times the pile diameter up to a maximum of 5,000 psf can be used. Soldier piles should be spaced at least three pile diameters, center to center. Continuous lagging will be required throughout. The soldier piles should be designed for the full- anticipated lateral pressure; however, the pressure on the lagging will be less due to arching in the soils. For design of lagging, the earth pressure can be limited to a maximum value of 400 psf. 8.1.9 Slopes All permanent slopes should be constructed no steeper than 2:1 (horizontal:vertical). Faces of fill slopes should be compacted either by rolling with a sheep-foot roller or other suitable equipment, or by overfilling and cutting back to design grade. All slopes are susceptible to surficial slope failure and erosion. Water should not be allowed to flow over the top of slopes. Additionally, slopes should be planted with vegetation that will reduce the potential for erosion. 'It ONE Infrastructure Engineering Corporation March 3, 2016 OMWD Building D SCST No. 160105P3-1 Encinitas, California Page 8 8.1.10 Site Excavation Characteristics It is anticipated that excavations can be achieved with conventional earthwork equipment in good working order. 8.1.11 Surface Drainage Final surface grades around structures should be designed to collect and direct surface water away from the structure and toward appropriate drainage facilities. The ground around the structure should be graded so that surface water flows rapidly away from the structure without ponding. In general, we recommend that the ground adjacent to the structure slope away at a gradient of at least 2%. Densely vegetated areas where runoff can be impaired should have a minimum gradient of at least 5% within the first 5 feet from the structure. Roof gutters with downspouts that discharge directly into a closed drainage system are recommended on structures. Drainage patterns established at the time of fine grading should be maintained throughout the life of the proposed structures. Site irrigation should be limited to the minimum necessary to sustain landscape growth. Should excessive irrigation, impaired drainage, or unusually high rainfall occur, saturated zones of perched groundwater can develop. 8.1.12 Grading Plan Review SCST should review the grading plans and earthwork specifications to ascertain whether the intent of the recommendations contained in this report have been implemented, and that no revised recommendations are needed due to changes in the development scheme. 8.2 FOUNDATIONS 8.2.1 Mat Foundations Due to the potential for ground movement during a seismic event, we recommend that the building be constructed on a mat foundation unless ground improvement is performed. Mat foundations should be underlain by compacted fill. A modulus of subgrade reaction of 200 pounds per cubic inch (pci) can be used for structural design. An allowable bearing capacity of 1,500 pounds per square foot (psf) can be used. The bearing value can be increased by % when considering the total of all loads, including wind or seismic forces. Footings located adjacent to or within slopes should be extended to a depth such that a minimum horizontal distance of 7 feet exists between the lower outside footing edge and the face of the slope. 8.2.2 Resistance to Lateral Loads Lateral loads will be resisted by friction between the bottoms of foundations and passive pressure on the faces of foundations and other structural elements below grade. An allowable coefficient of friction of 0.30 can be used. Passive pressure can be computed "It 'IL Infrastructure Engineering Corporation March 3, 2016 OMWD Building 0 SCST No. 160105P3-1 Encinitas, California Page 9 using an allowable lateral pressure of 350 psf per foot of depth below the ground surface for level ground conditions. The passive pressure can be increased by % when considering the total of all loads, including wind or seismic forces. The upper I foot of soil should not be relied on for passive support unless the ground is covered with pavements or slabs. 8.2.3 Settlement Characteristics The estimated mat foundation settlements are as follows: Static: 1 inch total % inch differential over a distance of 40 feet Seismic: 2 inches total 1 inch differential across the structure 8.2.4 Moisture Protection Moisture protection should be installed beneath the mat foundation where moisture sensitive floor coverings will be used. The project architect should review the tolerable moisture transmission rate of the proposed floor covering and specify an appropriate moisture protection system. Typically, a plastic vapor barrier is used. Minimum 10-mil plastic is recommended. The plastic should comply with ASTM El 745. The vapor barrier installation should comply with ASTM E1643. Construction practice often includes placement of a 2-inch thick sand cushion between the bottom of the concrete slab and the vapor barrier. This cushion can provide some protection to the vapor barrier during construction, and may assist in reducing the potential for edge curling in the slab during curing. However, the sand layer also provides a source of moisture to the underside of the slab that can increase the time required to reduce vapor emissions to limits acceptable for the type of floor covering placed on top of the slab. The slab can be placed directly on the vapor barrier. 8.2.5 Foundation Plan Review SCST should review the foundation plans to ascertain that the intent of the recommendations in this report has been implemented and that revised recommendations are not necessary as a result of changes after this report was completed. 8.2.6 Foundation Excavation Observations A representative from SCST should observe the foundation excavations prior to forming or placing reinforcing steel. 8.3 EXTERIOR SLABS-ON-GRADE The top 2 feet of material below exterior concrete slabs-on-grade should have an expansion index of 20 or less determined in accordance with ASTM D4829. Exterior slabs should be at ON 'it Infrastructure Engineering Corporation March 3, 2016 OMWD Building D SCST No. 160105P3-1 Encinitas, California Page 10 least 4 inches thick and reinforced with at least No. 3 bars at 18 inches on center each way. Slabs should be provided with weakened plane joints. Joints should be placed in accordance with the American Concrete Institute (ACI) guidelines. The project architect should select the final joint patterns. A 1-inch maximum size aggregate mix is recommended for concrete for exterior slabs. The corrosion potential of on-site soils with respect to reinforced concrete will need to be taken into account in concrete mix design. Coarse and fine aggregate in concrete should conform to the "Greenbook" Standard Specifications for Public Works Construction. 8.4 CONVENTIONAL RETAINING WALLS 8.4.1 Foundations Retaining walls can be supported on shallow spread footings with bottoms levels on compacted fill. Footings should extend at least 18 inches below lowest adjacent finished grad and should be at least 24 inches wide. An allowable bearing capacity of 2,500 psf can be used. The bearing value can be increased by 1/3 when considering the total of all loads, including wind or seismic forces. Footings located adjacent to or within slopes should be extended to a depth such that a minimum horizontal distance of 7 feet exists between the lower outside footing edge and the face of the slope. The recommendations provided above for resistance to lateral loads are applicable for retaining wall foundations. 8.4.2 Lateral Earth Pressures The active earth pressure for the design of unrestrained retaining walls with level backfill can be taken as equivalent to the pressure of a fluid weighing 35 pcf. The at-rest earth pressure for the design of restrained retaining walls with level backfills can be taken as equivalent to the pressure of a fluid weighing 55 pcf. These values assume a granular and drained backfill condition. An additional 20 pcf should be added to these values for walls with a 2:1 (horizontal:vertical) sloping backfill. An increase in earth pressure equivalent to an additional 2 feet of retained soil can be used to account for surcharge loads from light traffic. The above values do not include a factor of safety. Appropriate factors of safety should be incorporated into the design. If any other surcharge loads are anticipated, SCST should be contacted for the necessary increase in soil pressure. Retaining walls should be designed to resist hydrostatic pressures or be provided with a backdrain to reduce the accumulation of hydrostatic pressures. Backdrains can consist of a 2-foot wide zone of %-inch crushed rock separated from the adjacent soils using a nonwoven filter fabric (Mirafi 140N or equivalent). Weep holes should be provided or a perforated pipe should be installed at the base of the backdrain and sloped to discharge to a suitable storm drain facility. As an alternative, a geocomposite drainage system such as Miradrain 6000 or equivalent placed behind the wall and connected to a suitable storm drain facility can be used. The project architect should provide waterproofing specifications and details. Figure 5 presents typical conventional retaining wall backdrain details. off Infrastructure Engineering Corporation March 3, 2016 OMWD Building D SCST No. 160105P3-1 Encinitas, California Page 11 8.4.3 Seismic Earth Pressure If required, the seismic earth pressure can be taken as equivalent to the pressure of a fluid weighing 16 pcf. This value is for level backfill and does not include a factor of safety. Appropriate factors of safety should be incorporated into the design. This pressure is in addition to the un-factored, static active earth pressure. The passive pressure and bearing capacity can be increased by % in determining the seismic stability of the wall. 8.4.4 Backfill Wall backfill should consist of granular, free-draining material. Expansive or clayey soil should not be used. Additionally, backfill within 3 feet from the back of the wall should not contain rocks greater than 3 inches in dimension. We anticipate that a portion of the onsite soils will be suitable for wall backfill. Backfill should be compacted to at least 90% relative compaction. Backfill should not be placed until walls have achieved adequate structural strength. Compaction of wall backfill will be necessary to minimize settlement of the backfill and overlying settlement sensitive improvements. However, some settlement should still be anticipated. Provisions should be made for some settlement of concrete slabs and pavements supported on backfill. Additionally, any utilities supported on backfill should be designed to tolerate differential settlement. 8.5 MECHANICALLY STABILIZED EARTH RETAINING WALLS The following soil parameters can be used for design of mechanically stabilized earth (MSE) retaining walls. MSE Wall flAskin Psrsmstsrs Soil Parameter Reinforced Soil Retained Soil Foundation Soil Internal Friction Angle 320 320 32° Cohesion 1 0 0 0 Moist Unit Weight 1 125 pcf 125 pcf 125 pcf The reinforced soil should consist of granular, free-draining material with an expansion index of 20 or less. The bottom of MSE walls should extend to such a depth that a total of 5 feet exists between the bottom of the wall and the face of the slope. Figure 6 presents a typical MSE retaining wall backdrain detail. MSE retaining walls may experience lateral movement over time. The wall engineer should review the configuration of proposed improvements adjacent to the wall and provide measures to help reduce the potential for distress to these improvements from lateral movement. Infrastructure Engineering Corporation March 3, 2016 OMWD Buildina D SCSTNo. 160105P3-1 Page 12 8.6 PIPELINES 8.6.1 Thrust Blocks For level ground conditions, a passive earth pressure of 350 psf per foot of depth below the lowest adjacent final grade can be used to compute allowable thrust block resistance. A value of 150 psf per foot should be used below groundwater level, if encountered. 8.6.2 Modulus of Soil Reaction A modulus of soil reaction (E') of 2,000 psi can be used to evaluate the deflection of buried flexible pipelines. This value assumes that granular bedding material is placed adjacent to the pipe and is compacted to at least 90% relative compaction. 8.6.3 Pipe Bedding Pipe bedding as specified in the "Greenbook" Standard Specifications for Public Works Construction can be used. Bedding material should consist of clean sand having a sand equivalent not less than 30 and should extend to at least 12 inches above the top of pipe. Alternative materials meeting the intent of the bedding specifications are also acceptable. Samples of materials proposed for use as bedding should be provided to the engineer for inspection and testing before the material is imported for use on the project. The onsite materials are not expected to meet "Greenbook" bedding specifications. The pipe bedding material should be placed over the full width of the trench. After placement of the pipe, the bedding should be brought up uniformly on both sides of the pipe to reduce the potential for unbalanced loads. No voids or uncompacted areas should be left beneath the pipe haunches. Ponding or jetting the pipe bedding should not be allowed. 8.7 PAVEMENT SECTION RECOMMENDATIONS The pavement support characteristics of the soils encountered during our investigation are considered moderate. An R-value of 26 was assumed for design of preliminary pavement sections. The actual R-value of the subgrade soils should be determined after grading and final pavement sections be provided. Based on an R-value of 26, the following pavement structural sections are recommended for the assumed Traffic Indices. Flexible Pavement Sections Traffic Type Traffic Index Asphalt Concrete (inches) Aggregate Base* (inches) Parking Stalls 4.5 3 5 Drive Lanes 6.0 4 8 Heavy Traffic Areas 7.0 4 11 ?uuregdw Darpe 5UUUIU curijurm 10 %.Id55 £ ygregae oase in accoruance wiin tne autrans aanaara apeciTications or crushed Miscellaneous Base In accordance with the "Greenbook." ON Infrastructure Engineering Corporation March 3, 2016 OMWD Building D SCST No. 160105P3-1 Encinitas, California Page 13 Portland Cement Concrete Pavement Sections Traffic Type Traffic Index Full-Depth JPCP* (inches) Parking Stalls 4.5 6 Drive Lanes 6.0 6Y2 Heavy Traffic Areas j 7.0 1 7 Jointed Plain concrete Pavement The top 12 inches of subgrade should be scarified, moisture conditioned to near optimum moisture content and compacted to at least 95% relative compaction. Aggregate base and asphalt concrete should be compacted to at least 95% relative compaction. All soft or yielding areas should be removed and replaced with compacted fill or aggregate base. All materials and methods of construction should conform to good engineering practices and the minimum local standards. 8.8 PERVIOUS PAVEMENT SECTION RECOMMENDATIONS Pervious pavement section recommendations are based on Caltrans (2014) pavement structural design guidelines. The pavement sections below are based on the strength of the materials. However, the actual thickness of the sections may be controlled by the reservoir layer design, which the project civil engineer should determine. Pervious Asphalt Pavement *Asphalt Treated Permeable Base Traffic Type Category Permeable Base (ATPB) (inches) (inches) Parking Stalls B 5 9 -i incn or an open graaea mci on course uurj snouua ne piacea on top OT inc RI r. Pervious Concrete Pavement Traffic Type Category Pervious Concrete Permeable Base (inches) (inches) Parking Stalls B 51/2 6 Permeable Interlocking Concrete Payers (PICP) Traffic Type Category PICP Permeable Base (inches) (inches) Parking Stalls B Minimum 3% 10 The top 12 inches of subgrade should be scarified, moisture conditioned to near optimum moisture content and compacted to at least 95% relative compaction if infiltration is not used. Infrastructure Engineering Corporation March 3, 2016 OMWD Building D SCST No. 160105P3-1 Encinitas, California Page 14 The permeable base should consist of a Caltrans Class 4 Aggregate Base. All soft or yielding subgrade areas should be removed and replaced with compacted fill or permeable base if infiltration is used. All materials and methods of construction should conform to good engineering practices and the minimum local standards. We recommend installing deepened curbs or vertical cutoff membranes consisting of 30 mil HDPE or PVC at the edges of pervious pavements to reduce the potential for water-related distress to adjacent structures or improvements. The membrane should extend below the reservoir section. If infiltration is not used, the membrane should also be placed between the subgrade and pervious base, and a suitable subdrain system should be installed. 8.9 SOIL CORROSIVITY A representative sample of the onsite soils was tested to evaluate corrosion potential. The test results are presented in Appendix II. The project design engineer can use the sulfate results in conjunction with ACI 318 to specify the water/cement ratio, compressive strength and cementitious material types for concrete exposed to soil. A corrosion engineer should be contacted to provide specific corrosion control recommendations. 8.10 INFILTRATION We performed four borehole percolation tests at the approximate locations shown on Figure 3. Appendix III presents the results of the tests. The test results indicate infiltration rates between <0.1 inch per hour and about 3.8 inches per hour. The infiltration rate of the actual soils that will be encountered at the bottom of storm water retention basins could vary significantly subsequent to grading. An adequate safety factor should be applied to the infiltration rate during design of the proposed infiltration facilities. Site characteristics such as excessive slope of the drainage area, fine-grained soil types, and proximate location of the water table may preclude the use of an infiltration basin. Generally, infiltration basins are not suitable for areas with relatively impermeable soils containing clay and silt or in areas with fill. Further testing of the actual basin subgrade soils is recommend following grading. Additionally, infiltration basins will require periodic maintenance to function as intended. 9. GEOTECHNICAL ENGINEERING DURING CONSTRUCTION The geotechnical engineer should review project plans and specifications prior to bidding and construction to check that the intent of the recommendations in this report has been incorporated. Observations and tests should be performed during construction. If the conditions encountered during construction differ from those anticipated based on the subsurface exploration program, the presence of the geotechnical engineer during construction will enable an evaluation of the exposed conditions and modifications of the recommendations in this report or development of additional recommendations in a timely manner. Infrastructure Engineering Corporation March 3, 2016 OMWD Buildina D SCST No. 160105P3-1 Page 15 CLOSURE SCST should be advised of any changes in the project scope so that the recommendations contained in this report can be evaluated with respect to the revised plans. Changes in recommendations will be verified in writing. The findings in this report are valid as of the date of this report. Changes in the condition of the site can, however, occur with the passage of time, whether they are due to natural processes or work on this or adjacent areas. In addition, changes in the standards of practice and government regulations can occur. Thus, the findings in this report may be invalidated wholly or in part by changes beyond our control. This report should not be relied upon after a period of two years without a review by us verifying the suitability of the conclusions and recommendations to site conditions at that time. In the performance of our professional services, we comply with that level of care and skill ordinarily exercised by members of our profession currently practicing under similar conditions and in the same locality. The client recognizes that subsurface conditions may vary from those encountered at the boring locations, and that our data, interpretations, and recommendations are based solely on the information obtained by us. We will be responsible for those data, interpretations, and recommendations, but shall not be responsible for interpretations by others of the information developed. Our services consist of professional consultation and observation only, and no warranty of any kind whatsoever, express or implied, is made or intended in connection with the work performed or to be performed by us, or by our proposal for consulting or other services, or by our furnishing of oral or written reports or findings. 11. REFERENCES American Concrete Institute (ACI) (2012), Building Code Requirements for Structural Concrete (ACI 318-11) and Commentary, August. California Emergency Management Agency, California Geological Survey, University of Southern California (Cal EMA) (2009), Tsunami Inundation Map for Emergency Planning, National City Quadrangle, June 1. Caltrans (2010), Standard Specifications. Caltrans (2014), Pervious Pavement Design Guidance, August. County of San Diego (2012), SanGIS Interactive Map. International Code Council (2012), 2013 California Building Code, California Code of Regulations, Title 24, Part 2, Volume 2 of 2, Based on the 2012 International Existing Building Code, Effective Date: January 1, 2014. Kennedy, M.P. and Tan, S.S. (2007), Geologic Map of the Oceanside 30' x 60' Quadrangle, California, California Geological Survey. Kleinfelder (2001), Preliminary Geotechnical Evaluation, Olivenhain Municipal Water District, Headquarters and Road Project, Encinitas, CA, Project No. 51-598601, December 12. Public Works Standards, Inc. (2011), "Greenbook," Standard Specifications for Public Works Construction, 2012 Edition. Figure: I C z SITE VICINITY MAP Date: March, 2016 I Ui SCST, Inc. OMWD Building D By: CJC/JCU I S k:I Encinitas, California Job No.: 160105P3-1 - f '"Al ici; ' is 1T ? . J'( - / — Project Site c... , /( .-. - - '------ -- ' L31 -' 1 ,-- 2 ) - S E C;]3):,'I .T•:.Q S 7 / &'r / \.' '-#L.• :— r r'kI L" ... t .. o : Ill , Z—( . a. ii 1 / o kh I I - i3 L r p 117.26667 V/ 117,25OOO W \Sc-55 117fl333: vi -. - 3 5 1SI.L — UXXIfLLI 0 - _- iO)riFTFS fsl ?tmd from TO?0 2CC NaiotiatGecgrapbi Holdings('-tcpc:cr C z USGS QUADRANGLE MAP Date: March, 2016 Figure: SCST, Inc. OMWD Building D By: CJC/JCU S Encinitas, California Job No.: 160105P3-1 r 119.15 T ,.6TE i PAD EL=121 12 IT& (5')4 PAD EL=121.12 cV NN N / N (391/2') B-4 (331/2') 'N / B-3 (281/21) I/ FF=116.5D B-2 (311/21) 12L12 PAD EL=12+ SCST LEGEND: B-4 Current Boring (5') 4 Location and Depth B-4 Previous Boring (331/21)+ Location and Depth (Kleinfelder, 2001) 9 1 C LU SCST, Inc. SI' P-4 Percolation Test T Location and Depth 0 0 40' GO' Scale SUBSURFACE EXPLORATION MAP Date: March, 2016 Figure: OMWD Building D By: JCU 3 Encinitas, California Job No.: 160105P3-1 '5:~Qvo NTsa 1) Ca 40 _j Tsa Kt Kt Kt KI Kp 25 20 -Kt 15 Qya QVoP10 y\ Tsa 6/ (U Pku 01. J4Kh Tsa 70 52 p0 3 I 33 Qya Qoa Qya 86 Tmo E 0 KI If Teo 70 85/ .'.S 0 QOp6-7 vo Td : KI 85 KI KI Qop Kp KI Qvoa TI Qvo VOD10l it Qvopi 10 Q6a Tt voa 01 4 Qya T Td oa Id Ope Qvopi2 4 Qvopio Td Qoa KI, Explanation: Qya Young alluvial flood-plain deposits (Holocene and late Pleistocene) Td Delmar Formation (middle Eocene) o 1 2 Mires Tsa Santiago Formation (middle Eocene) Scale REGIONAL GEOLOGY AND Date: March, 2016 Figure: NCO FAULT MAP By: CJC/JCU LLI ki - SCST, Inc. OMWD Building D Job No.: 160105P3-1 4 S Encinitas, California w Scale: Not to Scale "—Sloping Backfill 12' Miimum - Miradrain 6000 or equivalent, 2/3 Wall Height I 4" Perforated PVC - or ABS Pipe 3 Cu. Ft. Per Linear Ft of 3/4" Crushed Rock Enveloped in Filter Fabric I Sloping Backfill 18' Minimum 3/4" Crushed Rock, 2/3 Wall Height Enveloped in Filter Fabric 4" Perforated PVC or ABS Pipe '-I 1 12' Minimum Not to Scale NOTES Waterproof back of wall following architect's specifications. 4" minimum perforated pipe, SDR35 or equivalent, holes down, 1% fall to outlet. Provide solid outlet pipe at suitable locations. Drain instalation and outlet connection should be observed by the geotechnical consultant. TYPICAL RETAINING WALL BACKDRAIN DETAILS OMWD Building D rn SCSI, Inc. Encinitas, California By: JCU Date: March, 2016 Job Number: 160105P3-1 Figure: 5 'Thick Soil Cap ? Minimum Fabric (Reinforced Soil) Geosynthetic Reinforcement (Designed by Others) Approximate Limits of Backcut (Retained Soil) 4" Perforated PVC or ABS Pipe Unreinforced Concrete Cu. Ft Per Linear Ft of 3/4" Crushed or Crushed Stone Leveling Pad Rock Enveloped in Filter Fabric (Foundation Soil) Not to Scale NOTES Backcut as recommended by the geotechnical report or field evaluation. Additional drain at excavation backcut may be recommended based on conditions observed during construction. Filter fabric should be installed between crushed rock and soil. Filter fabric should consist of Mirafi 140N or equivalent. Filter fabric should be overlapped approximately 6 inches. Perforated pipe should outlet through a solid pipe to an appropriate gravity outfall. Perforated pipe and outlet pipe should have a fall of at least 1%. Drain installation and outlet connection should be observed by the geotechnical consultant. TYPICAL MSE RETAINING WALL DETAIL NNI-31 OWMD Building D SCST, INC. Encinitas, California MOE By: JCU 'Date: March, 2016 Job No: 160105P3-1 IFigure: 6 APPENDIX I APPENDIX I FIELD INVESTIGATION Our field investigation consisted of a visual reconnaissance of the site drilling four borings and four percolation test holes on February 8, 2016 to depths between about 5 and 391A feet below the existing ground surface using a truck-mounted drill rig equipped with a hollow stem auger. Kleinfelder (2001) previously drilled one boring to a depth of about 33Y2 feet below the existing ground surface in the area of the planned building using a truck-mounted drill rig equipped with a hollow stem auger. Figure 3 shows the approximate locations of the borings and percolation test holes. The field investigation was performed under the observation of an SCSI engineer who also logged the borings and test holes and obtained samples of the materials encountered. Relatively undisturbed samples were obtained using a modified California (CAL) sampler, which is ring-lined split tube sampler with a 3-inch outer diameter and 2V2-inch inner diameter. Standard Penetration Tests (SPT) were performed using a 2-inch outer diameter and 1%-inch inner diameter split tube sampler. The CAL and SPT samplers were driven with a 140-pound weight dropping 30 inches. The number of blows needed to drive the samplers the final 12 inches of an 18-inch drive is noted on the borings logs as "Driving Resistance (blows/foot of drive)? SPT and CAL sampler refusal was encountered when 50 blows were applied during any one of the three 6- inch intervals, a total of 100 blows was applied, or there was no discernible sampler advancement during the application of 10 successive blows. The SPT penetration resistance was normalized to a safety hammer (cathead and rope) with a 60% energy transfer ratio in accordance with ASTM D6066. The normalized SPT penetration resistance is noted on the boring logs as "N60." Disturbed bulk samples were obtained from the SPT sampler and drill cuttings. The soils are classified in accordance with the Unified Soil Classification System as illustrated on Figure I-I. Logs of the current borings and percolation test holes are presented on Figures 1-2 through 1-12. The log of the previous Kleinfelder boring is also included. ml' SUBSURFACE EXPLORATION LEGEND UNIFIED SOIL CLASSIFICATION CHART SOIL DESCRIPTION GROUP TYPICAL NAMES SYMBOL COARSE GRAINED, more than 50% of material is larger than No. 200 sieve size. GRAVELS CLEAN GRAVELS GW Well graded gravels, gravel-sand mixtures, little or no fines More than half of coarse fraction is GP Poorly graded gravels, gravel sand mixtures, little or no fines. larger than No. 4 sieve size but,, GRAVELS WITH FINES GM smaller than 3 Silty gravels, poorly graded gravel-sand-silt mixtures. (Appreciable amount of fines) GC Clayey gravels, poorly graded gravel-sand, clay mixtures. SANDS CLEAN SANDS SW More than half of Well graded sand, gravelly sands, little or no fines. coarse fraction is SP Poorly graded sands, gravelly sands, little or no fines. smaller than No. 4 sieve size. SM Silty sands, poorly graded sand and silty mixtures. SC Clayey sands, poorly graded sand and clay mixtures. FINE GRAINED, more than 50% of material is smaller than No. 200 sieve size. SILTS AND CLAYS ML Inorganic silts and very fine sands, rock flour, sandy silt or clayey-silt- (Liquid Limit less sand mixtures with slight plasticity. than 50) CL Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, silty clays, lean clays. OL Organic silts and organic silty clays or low plasticity. SILTS AND CLAYS MH Inorganic silts, micaceous or diatomaceous fine sandy or silty soils, (Liquid Limit elastic silts. greater than 50) CH Inorganic clays of high plasticity, fat clays. OH Organic clays of medium to high plasticity. HIGHLY ORGANIC SOILS PT Peat and other highly organic soils. SAMPLE SYMBOLS LABORATORY TEST SYMBOLS - Bulk Sample AL - Atterberg Limits CAL - Modified California sampler CON - Consolidation CK - undisturbed Chunk sample COR - Corrosivity Tests MS - Maximum Size of Particle (Resistivity, pH, Chloride, Sulfate) ST - Shelby Tube DS - Direct Shear SPT I - Standard Penetration Test sampler El - Expansion Index MAX - Maximum Density GROUNDWATER SYMBOLS RV - R-Value V -Water level at time of excavation or as indicated SA - Sieve Analysis WA - No. 200 Sieve Wash (71%) (Percent Passing No. 200 Sieve) - Water seepage at time of excavation or as indicated RW - Response to Wetting z OMWD Building D Encinitas, California "if' L. OO I 1I'. By: CJM Date: March, 2016 Job Number: 160105133-1 Figure: I-I LOG OF BORING B-I Date Drilled: 2/8/2016 Logged by: CTL Equipment: CME 95 with 8-inch Hollow Stem Auger Project Manager: TBC Elevation (ft): 120'/2 Depth to Groundwater (ft): 15 SAMPLES U) .-'. .a: F- --Ui a) z F- w Ui ' I CD I— > '0 U) Z Z 0 0 - Ui 0 a. SUMMARY OF SUBSURFACE CONDITIONS (Q) Ui ZO - Z I— 0 0 - 0 - 4 Inches of asphalt concrete. - - - - - - - SM YOUNG ALLUVIAL FLOOD PLAIN DEPOSITS (Qva): SILTY SAND, moderate brown, fine to medium grained, moist, loose. -2 - 3 SPT X5 6 -4 -5 -- - 6 CAL 15 11.5 100.7 -7 -8 -9 -10 - - 11 SPT 7 9 -12 -13 -14 - 15 Groundwater level on 2/8/16. - - 16 Wet. CAL 12 22.6 101.8 - 17 -18 UFT - PARCLAY, moderate brown, wet, very stiff. -19 SPT 14 18 -20 ___________________________________________ - - - - - - - - BORING CONTINUED ON 1-3. OMWD Building D Now I - ' ma Encinitas, California I SCST, Inc. By: CJM IDate: March, 2016 I iJob Number: 160105P3-1 IFiaure: 1-2 I LOG OF BORING B-I (Continued) Date Drilled: 2/8/2016 Logged by: CTL Equipment: CME 95 with 8-inch Hollow Stem Auger Project Manager: TBC Elevation (ft): 120Y2 Depth to Groundwater (ft): 15 SAMPLES --w c. Cl) 0 Z? CL w I I— SUMMARY OF SUBSURFACE CONDITIONS ZO D - Z 0 CO CH YOUNG ALLUVIAL FLOOD PLAIN DEPOSITS (Oval: SANDY FAT CLAY, moderate brown, wet, very stiff. 21 SC CLAYEY SAND, moderate brown, fine grained, wet, medium dense. -22 SPT 9 12 23 -24 - SPT 12 15 WA 25 (21%) -26 -27 - -28 SPT 10 13 29 -30 -31 'Cy very stiff. SPT 11 14 -32 -33 - 34 SPT 14 18 -35 - 36 SC CLAYEY SAND, moderate brown and gray, fine grained, wet, dense. SPT 26 33 -37 - SANTIAGO FORMATION (Tsai: CLAYSTONE, gray, fine grained, moist, hard. - SILTY SANDSTONE, reddish-brown, fine to medium grained, moist, very dense, SPT 68 85 ' 140 weakly cemented. —BORING TERMINATED AT 391/2 FEET. 0 E 0 OMWD Building D I W Encinitas, California I SCST, Inc. By: CJM IDate: March, 2016 I IJob Number: 160105P3-1 IFigure: 1-3 I LOG OF BORING B-2 Date Drilled: 2/8/2016 Logged by: CTL Equipment: CME 95 with 8-inch Hollow Stem Auger Project Manager: TBC Elevation (ft): 118'/2 Depth to Groundwater (ft): 11 /2 SAMPLES --w U) a) - I- z 0. I- I- U) w > w I I- U) I.- z — >- I Q z 0 E 5 z 0 0 W 0 SUMMARY OF SUBSURFACE CONDITIONS > -j W — zo I- 0 U) > — a - 4 Inches of asphalt concrete. — - - — — — SM YOUNG ALLUVIAL FLOOD PLAIN DEPOSITS (Oval: SILTY SAND, moderate -I brown, fine to medium grained, moist, loose. -2 SA -3 CAL 12 13.4 99.2 AL El COR - -5 -- - 6 Light brown. SPT 6 8 -7 -8 -9 -10 — CAL 11 20.8 102.5 Groundwater level on 2/8/16 - - 12 Wet. -13 -14 -15 5CAWAibtiw oi&d grained, - -16 SPT 12 16 —17 -18 — -19 SPT 12 16 WA (42%) -20— BORING CONTINUED ON 1-5- ME I muza SCSI, Inc. OMWD Building D Encinitas, California By: CJM Date: March, 2016 Job Number: 160105P3-1 Figure: 1-4 LOG OF BORING B-2 (Continued) Date Drilled: 2/8/2016 Logged by: CTL Equipment: CME 95 with 8-inch Hollow Stem Auger Project Manager: TBC Elevation (ft): 118'A Depth to Groundwater (ft): 111/2 SAMPLES - - ' c. Cl) 0 w - Z .S I- I- w LU I I- Z SUMMARY OF SUBSURFACE CONDITIONS co 5; it 0 I. SC YOUNG ALLUVIAL FLOOD PLAIN DEPOSITS (Qva: CLAYEY SAND, light brown, -21 fine to medium grained, wet, loose. - -22 SPT 7 9 23 24 - -25 Medium dense. SPT 15 19 SANTIAGO FORMATION (Tsa): CLAYEY SANDSTONE, brownish-yellow, fine to medium grained, moist, dense. - 26 27 - 28 Very dense, weakly cemented. SPT 42 53 29 30 - 31 SPT 50 63 32 BORING TERMINATED AT 311/2 FEET. 33 .34 35 -36 -37 -38 -39 -40— OMWD Building D I Now Encinitas, California I SCSI, Inc. By: CJM IDate: March, 2016 Job Number: 160105P3-1 IFigure: 1-5 I LOG OF BORING B-3 Date Drilled: 2/8/2016 Logged by: CTL Equipment: CME 95 with 8-inch Hollow Stem Auger Project Manager: TBC Elevation (ft): 118'/2 Depth to Groundwater (ft): 12 SAMPLES . U) --uJ 0 .2 I— Z W .2: I U) W g U) z - I() U) z Ui -' Ui E co 0 Z Ui 0.SUMMARY OF SUBSURFACE CONDITIONS > Ui c 0 U) >- - - 4 inches of asphalt concrete. - - - - - - - SM YOUNG ALLUVIAL FLOOD PLAIN DEPOSITS (Ova): SILTY SAND, moderate - brown, fine to medium grained, moist, loose to medium dense. -2 -3 -4 -5 -6 -7 -8 -9 -10 - 11 17 Groundwater level on 218/16 -13 SC CLAYEY SAND, moderate brown, fine to medium grained, wet, medium dense. SPT 13 17 -14 15 CH SANDY FAT CLAY, moderate brown, fine grained, wet, very stiff. - -16 SPT 14 18 WA (71%) -17 -18 - -19 SPT 16 21 -20— - - - - - - BORING CONTINUED ON 1-5. OW OMWD Building D I Encinitas, California I scsi, Inc. By: CJM IDate: March, 2016 I IJob Number: 160105P3-1 IFigure: 1-6 I LOG OF BORING B-3 (Continued) Date Drilled: 2/8/2016 Logged by: CTL Equipment: CME 95 with 8-inch Hollow Stem Auger Project Manager: TBC Elevation (ft): 118½ Depth to Groundwater (ft): 12 SAMPLES a Cl) --w 0 a, _ Z w CL . I— I w I.-. I— 0 VJ z 0 Z° Q C.) LLI SUMMARY OF SUBSURFACE CONDITIONS D CO CH YOUNG ALLUVIAL FLOOD PLAIN DEPOSITS (Oval: SANDY FAT CLAY, moderate 21 brown, fine to medium grained, wet, very stiff. - 22 SPT 10 13 23 -24 b - -25 SPT 10 13 -26 -27 - SANTIAGO FORMATION (Taal : CLAYEY SANDSTONE, grayish-yellow and grayish- red, fine grained, moist, very dense. SPT 49 63 -28 -29 BORING TERMINATED AT 28'/2 FEET. -30 -31 -32 -33 -34 -35 -36 -37 -38 39 1 -40 1 OMWD Building D I I00. Encinitas, California I I SCSI, Inc. IBy: CJM IDate: March, 2016 i I Job Number: 160105P3-1 IFiciure: 1-7 I LOG OF BORING B-4 Date Drilled: 2/8/2016 Logged by: CTL Equipment: CME 95 with 8-inch Hollow Stem Auger Project Manager: TBC Elevation (ft): 117 Depth to Groundwater (ft): Not encountered SAMPLES w co -- C.) z— - I— z CL I— U) w W I I— C,) 0 C.) O SUMMARY OF SUBSURFACE CONDITIONS UJW Of In z I—D 0 0 —1 medium grained, moist, loose to medium dense. —2 -3 RV I -4 -5 -6 -7 -8 -9 -10 - 11 —12 -13 —14 —15 -16 —17 —18 —19 —20 U, OMWD Building D I Encinitas, California I ENE SCST, Inc. By: CJM IDate: March, 2016 I I Job Number: 160105P3-1 IFigure: 1-8 LOG OF BORING P-I Date Drilled: 2/8/2016 Logged by: CTL Equipment: CME 95 with 8-inch Hollow Stem Auger Project Manager: TBC Elevation (ft): 117 Depth to Groundwater (ft): Not encountered SAMPLES --w 0 CL Z W I— I w - - I— Q z Z 0 SUMMARY OF SUBSURFACE CONDITIONS 4 inches of asphalt concrete. 31V YOUNG ALLUVIAL FLOOD PLAIN DEPOSITS (Ova): SILTY SAND, moderate - - brown, fine to medium grained, moist, loose to medium dense. Percolation test performed at 5 feet. BORING TERMINATED AT 5 FEET. -6 -7 -8 -9 -10 -11 -12 - 13 -14 -15 -16 -17 -18 -19 -20 - ___________________________________________ - - - - - - - OMWD Building D 00.9 I Encinitas, California I u SCSI, Inc. By: CJM bate: March, 2016 I IJob Number: 160105P3-1 IFiaure: 1-9 I LOG OF BORING P-2 Date Drilled: 2/8/2016 Logged by: CTL Equipment: CME 95 with 8-inch Hollow Stem Auger Project Manager: TBC Elevation (ft): 117 Depth to Groundwater (ft): Not encountered --w SAMPLES _ 0. I— 4, I— Z — I— Cl) w W z I CD I— >- I Cl) Z CD'0 z 0 C.) - W 0 a. SUMMARY OF SUBSURFACE CONDITIONS - D E W zo — z 5;! I— 0 ! 0 >- - a - 4 inches of asphalt concrete. - - - - - - - SM YOUNG ALLUVIAL FLOOD PLAIN DEPOSITS (Qva: SILTY SAND, moderate brown, fine to medium grained, moist, loose to medium dense. -2 -3 -4 - Percolation test performed at 5 feet. - BORING TERMINATED AT 5 FEET. -6 -7 -8 -9 -10 - 11 - 12 - 13 - 14 —15 -16 —17 - 18 —19 -20— OMWD Building D I Noll Encinitas, California I SCST, Inc. By: CJM IDate: March, 2016 I Job Number: 160105P3-1 IFiaure: 1-10 I LOG OF BORING P.3 Date Drilled: 2/8/2016 Logged by: CTL Equipment: CME 95 with 8-inch Hollow Stem Auger Project Manager: TBC Elevation (ft): 116 Depth to Groundwater (ft): Not encountered SAMPLES ' U) --w I- Z .S I- I- U) w > w I- z I CD> I- U) 0 Z W -j E 0 0 W 0 a. SUMMARY OF SUBSURFACE CONDITIONS > Z Co W zo I- O U) - - 3 Inches of asphalt concrete. - - - - - - SM YOUNG ALLUVIAL FLOOD PLAIN DEPOSITS (Qva: SILTY SAND, moderate - brown, fine to medium grained, moist, loose to medium dense. -2 -3 -4 - Percolation test performed at 5 feet. - BORING TERMINATED AT 5 FEET. -6 -7 -8 -9 -10 -11 12 13 14 - 15 - 16 -17 -18 -19 -20— OMWD Building D — SCST, Encinitas, California By: CJM IDate: March, 2016 Job Number: 160105P3-1 1Figure: I-Il LOG OF BORING P.4 Date Drilled: 2/8/2016 Logged by: CTL Equipment: CME 95 with 8-inch Hollow Stem Auger Project Manager: TBC Elevation (ft): 116 Depth to Groundwater (ft): Not encountered SAMPLES -. C,) --w _ 0. I— C) I— Z ' I U) w Ui '— z I c — l— >- U) () z 5'0 SO o 0 w SUMMARY OF SUBSURFACE CONDITIONS E Z Ui I— Z 5 I— 0 U) - - 3 inches of asphalt concrete. - - - — - - - 3tid YOUNG ALLUVIAL FLOOD PLAIN DEPOSITS (Oval: SILTY SAND, moderate brown, fine to medium grained, moist, loose to medium dense. -2 -3 -4 - Percolation test performed at 5 feet. - BORING TERMINATED AT 5 FEET. -6 -7 -8 -9 -10 - 11 -12 -13 -14 -15 -16 -17 -18 -19 -20 - OMWD Building D No 2 I Encinitas, California I muz SCST, Inc. By: CJM IDate: March, 2016 IJob Number: 160105P3-1 IFigure: 1-12 I DATE QRILLED: 11/20/01 WATER DEPTH: 15 feet DRILLED BY: Tr—County Drilling DATE MEASURED: 11/20/2001 DRILLING METHOD: CME-75 HT, 140 lbs., 30" drop ELEVATION: 117'± KISL Autohammer LOGGED BY: BIB HOLE DIAMETER: 8" diameter Hollow Stem Auger REVIEWED BY: REL 8 SOIL DESCRIPTION C,) - - - Oft' LU - AND < -' CLASSIFICATION za - ja g ...jtSPHALT CONCRETE: Approximately 4" thick ALLUVIUM: SILTY SAND (SM), t, di,, medium dense, fine grained 115 - - 25 2 84.2 4.2 CORR - - 29 3 91.2 3.7 110 - 10— Moist, loose 13 4 .• :• 14.1 WA(23.1% 105 15- p p Wet, loose, increased clay content - P S 5 • 23.5 Note:SPT sampler has - - CLA Y SAND (SC), tan, w - - -room for - ! 14 6 • WA (29.3), k9 OUVENHAIN KL El NF ELDER MUNICIPAL WATER DISTRICT FIGURE HEADQUARTERS AND ROAD PROJECT 605 SHORMAM PLACE SAN DIEGO. CALIFORNIA 92122 CARLSBAD, CALIFORNIA A9 PROJECT NO. 51-5985-01 LOG OF BORING 4 - U) a. - -- UJ - 8 SOIL DESCRIPTION - - - U) I- AL og z o AND CLASSIFICATION D OE C.) (Continued From Previous Page) Orange-brown, coarser grained sand 14 - 7 95 - CLAYEY SAN]) (SC), tan with orange mottling, wet mediume - P8 8 - fine-grained 23.8 SA (32%), 25- p - ! 17 9 90 - - p P U 10 30- - SAND - 50I4 ii Total depth 33.5 feet Groundwater encountered at 15 feet ________ Boring backfilled 11/20/2001 35- 80 - 40- 75 - J9 OLIVENHAIN KL El N F E L D E R MUNICIPAL WATER DISTRICT FIGURE HEADQUARTERS AND ROAD PROJECT 5015 SHOREHAM PLACE SAN DIEGO, CAUFORN1A 02122 CARLSBAD, CALIFORNIA A10 PROJECT NO. 51-5985-01 LOG OF BORING 4 j APPENDIX II APPENDIX II LABORATORY TESTING Laboratory tests were performed to provide geotechnical parameters for engineering analyses. The following tests were performed: CLASSIFICATION: Field classifications were verified in the laboratory by visual examination. The final soil classifications are in accordance with the Unified Soil Classification System. IN SITU MOISTURE AND DENSITY: The in situ moisture content and dry unit weight were determined on samples collected from the borings. The test results are presented on the boring logs in Appendix I. GRAIN SIZE DISTRIBUTION: The grain size distribution was determined on one soil sample in accordance with ASTM D422. Figure Il-I presents the test results. ATTERBERG LIMITS: The Atterberg limits were determined on one soil sample in accordance with ASTM 04318. Figure Il-I presents the test results. FINES CONTENT: The amount of material finer than the No. 200 sieve was determined on three samples in accordance with ASTM D1140. Figure 11-2 presents the test results. R-VALUE: An R-value test was performed on one sample in accordance with California Test Method 301. Figure 11-2 presents the test result. EXPANSION INDEX: The expansion index was determined on one sample in accordance with ASTM D4829. Figure 11-2 presents the test results. CORROSIVITY: Corrosivity tests were performed on one soil sample. The pH and minimum resistivity were determined in accordance with California Test 643. The soluble sulfate content was determined in accordance with California Test 417. The total chloride ion content was determined in accordance with California Test 422. Figure 11-2 presents the test results. Soil samples not tested are now stored in our laboratory for future reference and analysis, if needed. Unless notified to the contrary, all samples will be disposed of 30 days from the date of this report. Room, NH U.e.aw,d.dSim 9k.. 6" 3" 1-W 3/4" 3/8" #4 #8810 916 #30 #40850 9100 #200 100 90 80 .970 60 50 30 20 10 1000 100 10 1 0.1 0.01 Grain Size in Millimeters Cobbles Gravel I Sand Silt or Clay Coarse I Fine I Coarse I Medium I Fine SAMPLE LOCATION UNIFIED SOIL CLASSIFICATION: SM B-2 at % to 5 feet DESCRIPTION SILTY SAND ATTERBERG LIMITS LIQUID LIMIT NP PLASTIC LIMIT NP PLASTICITY INDEX I NP OMWD Building 0 I I SCST Inc. jj I By: Encinitas, California CTL hate: March, 2016 Im FINES CONTENT ASTM D1140 R-VALUE CALIFORNIA TEST 301 EXPANSION INDEX ASTM D2489 CLASSIFICATION OF EXPANSIVE SOIL' ASTM - D4829 RESISTIVITY, pH, SOLUBLE CHLORIDE and SOLUBLE SULFATE SAMPLE RESISTIVITY (0-cm) pH CHLORIDE (%) SULFATE (%) B-2 at 1/2 to 5 feet 1,960 7.8 0.029 0.006 SULFATE EXPOSURE CLASSES 2 ACI 318, Table 19.3.1.1 OMWD Building D SCST, Inc. Encinitas, California By: CTL Date: March, 2016 MHz Job Number: 160105P3-1 Figure: 11-2 SAMPLE DESCRIPTION % FINER THAN #200 SIEVE B-I at 24 to 25½ ft CLAYEY SAND, moderate brown 21 B-2 at 18 to 191/2 ft CLAYEY SAND, light brown 42 B-3 at 15 to 16% t SANDY FAT CLAY, moderate brown 71 SAMPLE DESCRIPTION R- VALUE B-4 at 1/2 to 5 feet SILTY SAND, light brown 26 SAMPLE DESCRIPTION EXPANSION INDEX B-2 at 1/2 to 5 feet SILTY SAND, moderate brown 8 EXPANSION INDEX POTENTIAL EXPANSION 1-20 Very Low 21-50 Low f Uj 51 -90 Medium 91-130 High Above 130 Very High Class Severity Water-Soluble Sulfate (SO4) in Soil, Percent by Mass SO Not applicable SO4 < 0.10 SI Moderate 0-10!5 SO4 < 0.20 S2 Severe 0.20:5 SO4:5 2.00 S3 Very Severe SO4 > 2.00 APPENDIX Ill BOREHOLE PERCOLATION TESTING We performed falling head borehole percolation testing at four locations (P-I through P-4) in general conformance with Appendix C of the Model BMP Design Manual for San Diego Region. The borings were prepared for percolation testing by placing about 6 inches of pea gravel in the bottom of the test hole and then installing a 4-inch diameter solid PVC pipe from the top of the pea gravel (about 41,4 feet below the existing ground surface) to about 2 feet above the ground surface. Pea gravel was placed in the annular space between the PVC pipe and the boring sidewall between the depths of about 41/2 feet and about 2% feet below the ground surface; hydrated bentonite chips were placed above about 21/2 feet. Prior to starting the percolation testing, the test holes were presoaked overnight (approximately 16 hours) by filling the holes with water. The percolation testing was performed immediately after presoaking by filling the test holes with clean potable water to the top of the PVC pipe and measuring the drop in the water level every 30 minutes until a constant rate was established. Figures Ill-I through 111-4 present the results of the testing. 'It NI' Report of Falling Head Borehole Percolation Testing Storm Water Infiltration Project Name: Olivenhain MWD, Building D Test Location Number: P-i Job Number: 1601051`3 Date Drilled: 2/9/2016 Tested By: EM Drilling Method: Truck Mounted Drill Rig Date Tested: 2/10/2016 Drilled Depth: 5 Feet Presoak Time: 21 Hours Solid Pipe Interval: 0 to 44 Feet Reading Time Interval (mm) Initial Level (in) Final Level (in) Change in Level (in) Percolation Rate (in/mm) Percolation Rate (mm/in) 1 9:40 0:30 6.0 0.75 10:10 5.3 0.175 6 2 10:13 0:30 6.0 0.80 10:43 5.2 0.173 6 3 10:44 0:30 6.0 0.80 11:14 5.2 0.173 6 4 11:16 0:30 6.0 0.80 11:46 5.2 0.173 6 5 11:47 0:30 6.0 0.80 12:17 5.2 0.173 6 6 12:18 0:30 6.0 0.88 12:48 5.1 0.171 6 7 12:50 0:30 6.0 0.88 13:20 5.1 0.171 6 8 13:21 0:30 6.0 0.88 5.1 0.171 ________ 6 13:51 9 ______ 13:51 0:30 6.0 14:21 0.88 -F5.1 5 .1 0.171 6 6 mm/in Uncorrected Percolation Rate: F 10.31 in/hr I Gravel Correction Factor: 1.951 Corrected Percolation Rate: 3.0 mm/in 5.3 in/hr Estimated Infiltration Rate*: 3.8 in/hr I * Infiltration rates estimated using the Prochet Method on borehole percolation data. I OMWD Building D ONLU Encinitas, California H ,SCST, Inc. I By: EM IDate: March, 2016 IJob No: 160105P3-1 iFigure: Ill-i Report of Falling Head Borehole Percolation Testing Storm Water Infiltration Project Name: Olivenhain MWD, Building D Test Location Number: P-2 Job Number: 160105P3 Date Drilled: 2/9/2016 Tested By: EM Drilling Method: Truck Mounted Drill Rig Date Tested: 2/10/2016 Drilled Depth: 5 Feet Presoak Time: 21 Hours Solid Pipe Interval: 0 to 4% Feet Reading Time Interval (mm) Initial Level (in) Final Level (in) Change in Level (in) Percolation Rate (in/mm) Percolation Rate (min/ in) 1 9:41 0:30 6.0 2.00 10:11 4.0 0.133 7 2 10:12 0:30 6.0 2.13 10:42 3.9 0.129 8 3 10:44 0:30 6.0 2.25 11:14 3.8 0.125 8 4 11:15 0:30 6.0 2.25 11:45 3.8 0.125 8 5 11:46 0:30 6.0 2.50 12:16 3.5 0.117 9 6 12:17 0:30 6.0 2.50 12:47 3.5 0.117 9 7 12:47 0:30 6.0 3.00 13:17 3.0 0.100 10 8 13:18 0:30 13:48 6.0 3.00 3.0 0.100 10 9 13: 0:30 6.0 73.00 ___ 3.0 0.100 10 51 14:21 9 mm/in Uncorrected Percolation Rate: 6.70 in/hr I Gravel Correction Factor: 1.951 Corrected Percolation Rate: 4.6 mm/in 3.4 in/hr I Estimated Infiltration Rate*: 1.8 in/hr * Infiltration rates estimated using the Prochet Method on borehole percolation data. OMWD Building D I Encinitas, California I I SCST, Inc. IBy: EM IDate: March, 2016 M Hz IJob No: 160105P3-1 IFigure: 111-2 Report of Falling Head Borehole Percolation Testing Storm Water Infiltration Project Name: Olivenhain MWD, Building D Test Location Number: P-3 Job Number: 160105P3 Date Drilled: 2/9/2016 Tested By: EM Drilling Method: Truck Mounted Drill Rig Date Tested: 2/10/2016 Drilled Depth: 5 Feet Presoak Time: 21 Hours Solid Pipe Interval: 0 to 4',4 Feet Reading Time Interval (mm) Initial Level (in) Final Level (in) Change in Level (in) Percolation Rate (in/mm) Percolation Rate (mm/in) 1 10:21 0:30 7.0 5.5 10:51 1.5 0.050 20 2 10:52 0:30 6.0 5.0 11:22 1.0 0.033 30 3 11:23 0:30 6.0 4.8 1.3 0.042 24 11:53 4 11:53 0:30 6.0 4.8 1.3 0.042 24 12:23 5 12:24 0:30 6.0 4.5 12:54 1.5 0.050 20 6 12:55 0:30 6.0 4.5 13:25 1.5 0.050 20 7 13:26 0:30 6.0 4.5 1.5 0.050 20 13:56 8 13:57 0:30 6.0 4.5 1.5 0.050 20 14:27 Uncorrected Percolation Rate: 21 mm/in 2.90 in/hr I Gravel Correction Factor: 1.951 Corrected Percolation Rate: 10.7 mm/in 1.5 in/hr I Estimated Infiltration Rate*: 0.8 in/hr * Infiltration rates estimated using the Prochet Method on borehole II. SCST, Inc. ii colation data. OMWD Building D Encinitas, California EM Date: March, 2016 No: 160105P3-1 Figure: 111-3 Report of Falling Head Borehole Percolation Testing Storm Water Infiltration Project Name: Olivenhain MWD, Building D Test Location Number: P-4 Job Number: 160105P3 Date Drilled: 2/9/2016 Tested By: EM Drilling Method: Truck Mounted Drill Rig Date Tested: 2/10/2016 Drilled Depth: 5 Feet Presoak Time: 21 Hours Solid Pipe Interval: 0 to 4'/2 Feet Reading Time Interval (mm) Initial Level (in) Final Level (in) Change in Level (in) Percolation Rate (in/mm) Percolation Rate (min/ in) 1 10:22 0:30 21.5 21.1 10:52 0.4 0.013 80 2 10:53 0:30 21.1 20.8 11:23 0.4 0.013 79 3 11:24 0:30 20.8 20.5 11:54 0.3 0.008 120 4 11:55 0:30 20.5 20.3 12:25 0.3 0.008 120 5 12:26 0:30 20.3 20.0 12:56 0.3 0.008 120 6 12:58 0:30 20.0 19.8 13:28 0.3 0.008 120 7 13:29 0:30 19.8 19.5 13:59 0.3 0.008 120 8 14:00 0:30 19.5 19.3 1430 0.3 0.008 120 Uncorrected Percolation Rate: 120 mm/in 0.50 in/hr I Gravel Correction Factor: 1.951 Corrected Percolation Rate: 61.5 mm/in 0.3 in/hr I Estimated Infiltration Rate*: <0.1 in/hr * Infiltration rates estimated using the Prochet Method on borehole percolation data. OMWD Building D Encinitas, California I .03i I By: EM 'Date: March, 2016 I SCST Inc. IJob No: 160105P3-1 1Figure: 111-4