APPENDIX B GEOTECHNICAL INVESTIGATION

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1 APPENDIX B GEOTECHNICAL INVESTIGATION

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3 GEOTECHNICAL INVESTIGATION 2016 SEWER AND WATER GROUP 1 CIP, WATER PROJECT 1 15 TH STREET AND AVENIDA PRIMAVERA DEL MAR, CALIFORNIA PREPARED FOR: MR. TIM THIELE ENGINEERING DEPARTMENT CITY OF DEL MAR 1050 CAMINO DEL MAR DEL MAR, CALIFORNIA PREPARED BY: SCST, INC RIVERDALE STREET SAN DIEGO, CALIFORNIA Providing Professional Engineering Services Since 1959

4 June 24, 2016 SCST Project No P3.8 Report No. 1 Mr. Tim Thiele Engineering Department City of Del Mar 1050 Camino Del Mar Del Mar, California Subject: GEOTECHNICAL INVESTIGATION 2016 SEWER AND WATER GROUP 1 CIP, WATER PROJECT 1 15 TH STREET AND AVENIDA PRIMAVERA DEL MAR, CALIFORNIA Dear Mr. Thiele: SCST, Inc. (SCST) 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 May 24, If you have questions, please call us at (619) Respectfully Submitted, SCST, INC. Emil Rudolph, GE 2767 Andrew K. Neuhaus, CEG 2591 Principal Engineer Senior Geologist ER:AKN:aw (1) Addressee via at tthiele@mbakerintl.com

5 SECTION TABLE OF CONTENTS PAGE 1 INTRODUCTION SCOPE OF WORK SUBSURFACE EXPLORATION LABORATORY TESTING ANALYSIS AND REPORT PREPARATION SITE DESCRIPTION SUBSURFACE CONDITIONS CBC SEISMIC DESIGN PARAMETERS CONCLUSIONS AND RECOMMENDATIONS TEMPORARY EXCAVATION AND SHORING EXCAVATION CHARACTERISTICS DEWATERING HDD CHARACTERISTICS PIPELINES Pipeline Support Modulus of Soil Reaction Thrust Blocks Pipe Bedding Cutoff Walls Backfill CORROSIVITY GEOTECHNICAL ENGINEERING DURING CONSTRUCTION CLOSURE REFERENCES... 9 ATTACHMENTS FIGURES Figure 1... Site Vicinity Map Figure 2... Subsurface Exploration Map Figure 3... Geologic Cross Section APPENDICES Appendix I... Subsurface Exploration Appendix II... Laboratory Testing

6 1 INTRODUCTION This report presents the results of the geotechnical investigation that SCST, Inc. (SCST) performed for the subject project. We understand that the project will include the design and construction of a 6-inch high density polyethylene (HDPE) water line. The HDPE pipeline will replace the existing above-ground steel pipeline. We also understand the pipeline installation will utilize horizontal directional drill (HDD) techniques. 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. 2 SCOPE OF WORK 2.1 SUBSURFACE EXPLORATION We explored the subsurface conditions by drilling one boring to a depth of about 19½ feet below the existing ground surface using a truck-mounted drill rig equipped with a hollow stem auger, logging the bluff at the top of the slope, and excavating three test pits with hand tools near the face of the bluff. Figure 2 shows the approximate locations of the boring, slope log, and test pits. An SCST geologist logged the boring, bluff, and test pits and collected samples of the materials encountered for laboratory testing. The logs of the boring, bluff, and test pits are presented in Appendix I. Soils are classified according to the Unified Soil Classification System illustrated on Figure I LABORATORY TESTING Selected samples obtained from the boring, bluff, and test pits 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, and corrosivity. The results of the laboratory tests and brief explanations of the test procedures are presented in Appendix II. 2.3 ANALYSIS AND REPORT PREPARATION The results of the field and laboratory tests were evaluated to develop conclusions and recommendations regarding: Subsurface conditions beneath the site Criteria for seismic design in accordance with the 2013 California Building Code (CBC) Temporary excavations and shoring Excavation characteristics Pipeline support Resistance to lateral loads for the design of thrust blocks Pipe bedding materials Backfill placement and compaction Corrosion potential of the onsite soil

7 City of Del Mar June 24, Sewer and Water Group 1 CIP, Water Project 1 SCST No P3.8-1 Del Mar, California Page 2 3 SITE DESCRIPTION The site of the planned alignment is generally located north of the intersection of 15 th Street and Avenida Primavera in the City of Del Mar, California. The site consists of a west-east trending canyon that drains to the east. Existing improvements along the alignment consist of the existing water line. Vegetation in the alignment area consists of grasses, bushes and trees. 4 SUBSURFACE CONDITIONS The materials encountered in the boring and test pits, and observed in outcrops at the site consist of fill, very old paralic deposits, and Torrey Sandstone. Descriptions of the materials are presented below and distribution of the deposits is shown on Figures 2, 3 and I-3. Fill - The fill consists of medium dense silty sand with varying amounts of gravel. The fill extends to a depth of about 3 feet below the existing ground surface. Very Old Paralic Deposits - The very old paralic deposits consist of very dense, weakly cemented to moderately cemented silty to clayey sandstone. Torrey Sandstone The Torrey Sandstone was encountered as of very dense, moderately cemented silty sandstone. Groundwater - Groundwater was not encountered in the boring and test pits. Additionally, seepage was not observed in outcrops at the site. The groundwater table is expected to be below a depth that will influence planned construction. However, groundwater levels may fluctuate in the future due to rainfall, irrigation, broken pipes, or changes in site drainage. Because groundwater rise or seepage is difficult to predict, such conditions are typically mitigated if and when they occur. 5 CBC SEISMIC DESIGN PARAMETERS A geologic hazard that could affect the project is ground-shaking as a result of movement along an active fault in the vicinity of the site. The seismic design parameters in accordance with the 2013 CBC are presented below. Site Coordinates: Latitude Longitude Site Class: C Site Coefficients, F a = F v = Mapped Spectral Response Acceleration at Short Periods, S s = 1.173g Mapped Spectral Response Acceleration at 1-Second Period, S 1 = 0.453g S DS = 0.782g S D1 = 0.407g PGA M = 0.497g

8 City of Del Mar June 24, Sewer and Water Group 1 CIP, Water Project 1 SCST No P3.8-1 Del Mar, California Page 3 6 CONCLUSIONS AND RECOMMENDATIONS Based on the results of our investigation, we consider the planned construction is feasible from a geotechnical standpoint provided the recommendations of this report are followed. In our opinion, the site conditions are suitable to install the water pipeline using HDD and traditional open excavation trenching techniques. However, difficult drilling and trenching conditions should be expected in cemented zones within the very old paralic deposits and Torrey Sandstone. Cobbles and possibly boulders should also be anticipated within the very old paralic deposits. The materials anticipated below the pipeline depths are expected to generally provide good pipeline support. The onsite materials are generally not expected to meet Greenbook Standard Specifications for Public Works Construction material specifications for pipe bedding. They will, however, be suitable for use as backfill following removal of rocks greater than 6 inches in any dimension. The weight of the pipe and contents will be less than the materials excavated, and pipe settlements are expected to be negligible. 6.1 TEMPORARY EXCAVATION AND SHORING Temporary excavations will be required for the HDD pits and for open cut trenching. Temporary excavations 3 feet deep or less can be made vertically. Deeper temporary excavations in fill should be laid back no steeper than 1:1 (horizontal:vertical). Deeper temporary excavations in very old paralic deposits and Torrey Sandstone should be laid back no steeper than ¾:1. 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 trench. Excavated materials 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 the slopes to prevent runoff water from entering the excavation and eroding the slope faces. Slopes steeper than those described above will require shoring. Soldier piles and lagging, sheet piles, internally braced shoring, or trench boxes could be used. If trench boxes are used, the soil immediately adjacent to the trench box is not directly supported. Ground surface deformations immediately adjacent to the pit or trench could be greater where trench boxes are used compared to other methods of shoring. For design of cantilevered shoring with level backfill, the active earth pressure can be taken as equivalent to a fluid weighing 35 pounds per cubic foot (pcf). An additional 20 pcf should be added for shoring with 2:1 sloping ground. The surcharge loads on shoring from traffic and construction equipment working adjacent to the excavation can be modeled by assuming an

9 City of Del Mar June 24, Sewer and Water Group 1 CIP, Water Project 1 SCST No P3.8-1 Del Mar, California Page 4 additional 2 feet of soil behind the shoring. For design of soldier piles in very old paralic deposits, an allowable passive pressure of 350 psf per foot of embedment over two times the pile diameter up to a maximum of 7,500 psf can be used. Soldier piles should be spaced at least three pile diameters, center to center. 6.2 EXCAVATION CHARACTERISTICS It is anticipated that excavation can be achieved with conventional drilling and earthwork equipment in good working order. Difficult drilling and excavation should be anticipated in cemented zones within the very old paralic deposits and Torrey Sandstone. Cobbles and possibly boulders should also be anticipated within the very old paralic deposits. Contract documents should specify that the contractor mobilize equipment capable of excavating and compacting materials with concretions and cobbles/boulders. Rock breakers, carbide tipped augers, or carbide/diamond tipped coring equipment may be required to excavate/drill concretions or rocky materials. 6.3 DEWATERING Groundwater was not encountered in the borings. However, groundwater seepage into pits and trenches may occur locally following heavy rain or local irrigation. Dewatering can most effectively be accomplished by sloping the excavation bottom to a sump and pumping from the sump. A layer of gravel about 6 inches thick placed in the bottom of the excavation will facilitate groundwater flow and can be used as a working platform. If the gravel is kept clean, it can likely also be used for bedding. A sump and pump system might be necessary to remove accumulated water at the lower-elevation HDD pits. 6.4 HDD CHARACTERISTICS The anticipated alignment of trenchless excavation is expected to pass through fill, very old paralic deposits, and Torrey Sandstone with varying density. The borehole excavation should be drilled so that at least 10 feet of cover exists between the top of the borehole and the face of slope. In general, the subsurface explorations did not encounter soil that would prevent pushing the planned water line using conventional excavation equipment at the planned pipe depths. However, potential contractors should be informed that excavation conditions could vary significantly between test boring locations. The specifications should indicate that the contractor should have equipment on site to advance the crossing in very dense deposits with cobbles, to avoid the potential for delays during trenchless construction. Typically, HDD is a 2-step method. The first step consists of drilling a pilot hole along the planned alignment. The second step involves enlarging the pilot hole to the desired diameter. HDD is applicable to most soil conditions but will experience difficult drilling when cobbles and boulders are encountered. Contract documents should specify that the contractor have equipment capable of excavating and breaking the cobbles and boulders available on-site to

10 City of Del Mar June 24, Sewer and Water Group 1 CIP, Water Project 1 SCST No P3.8-1 Del Mar, California Page 5 reduce the potential for claims for delays if cobbles and boulders are encountered. In our opinion, this method is applicable for the construction of the new water line. For tunneling purposes, Table 1 provides classifications of materials encountered for the project based on the Tunnelman's Ground Classification which is presented in Table 2. Table 1 Tunnelman's Ground Classification Material Classification Fill Fast Ravelling Very Old Paralic Deposits Firm Torrey Sandstone Firm Table 2 Tunnelman's Ground Classification System Tunnelman's Ground Classification for Soils Classification Firm Raveling Slow raveling Fast raveling Behavior Heading can be advanced without initial support, and final lining can be constructed before ground starts to move. Chunks or flakes of material begin to drop out of the arch or walls sometime after the ground has been exposed, due to loosening or to overstress and "brittle" fracture (ground separates or breaks along distinct surfaces, opposed to squeezing ground). In fast raveling ground, the process starts within a few minutes, otherwise the ground is slow raveling. Typical Soil Types Loess above water table; hard clay, marl, cemented sand and gravel when not highly overstressed. Residual soils or sand with small amounts of binder may be fast raveling below the water table, slow raveling above. Stiff fissured clays may be slow or fast raveling depending upon degree of overstress. Squeezing Ground squeezes or extrudes plastically into Ground with low frictional strength. Rate tunnel, without visible fracturing or loss of of squeeze depends on degree of continuity, and without perceptible increase in overstress. Occurs at shallow to medium water content. Ductile, plastic yield and flow due depth in clay of very soft to medium to overstress. consistency. Stiff to hard clay under high cover may move in combination of raveling at excavation surface and squeezing at depth behind surface.

11 City of Del Mar June 24, Sewer and Water Group 1 CIP, Water Project 1 SCST No P3.8-1 Del Mar, California Page 6 Tunnelman's Ground Classification for Soils Classification Behavior Typical Soil Types Running Cohesive -running Running Flowing Swelling Granular materials without cohesion are unstable at a slope greater than their angle of repose (approx 30 o -35 o ). When exposed at steeper slopes they run like granulated sugar or dune sand until the slope flattens to the angle of repose. A mixture of soil and water flows into the tunnel like a viscous fluid. The material can enter the tunnel from the invert as well as from the face, crown, and walls, and can flow for great distances, completely filling the tunnel in some cases. Ground absorbs water, increases in volume, and expands slowly into the tunnel. Clean, dry granular materials. Apparent cohesion in moist sand, or weak cementation in any granular soil, may allow the material to stand for a brief period of raveling before it breaks down and runs. Such behavior is cohesiverunning. Below the water table in silt, sand, or gravel without enough clay content to give significant cohesion and plasticity. May also occur in highly sensitive clay when such material is disturbed. Highly pre-consolidated clay with plasticity index in excess of about 30, generally containing significant percentages of montmorillonite. 6.5 PIPELINES Pipeline Support It is anticipated that most of the materials along the pipeline alignment will provide adequate support for the pipe, although loose, soft, and otherwise unsuitable materials should be anticipated locally in fill. Unsuitable materials encountered near trench bottom levels, as determined during construction by the geotechnical consultant, should be excavated to competent material as determined by the geotechnical consultant. The excavated materials can be replaced as compacted fill or with pipe bedding material as described below. Unsuitable materials should be removed from the full width of the trench. The bottoms of the excavations should be observed by the geotechnical consultant prior to placement of pipe bedding 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.

12 City of Del Mar June 24, Sewer and Water Group 1 CIP, Water Project 1 SCST No P3.8-1 Del Mar, California Page 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 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 Cutoff Walls Where pipeline inclinations exceed 15 percent, cutoff walls may be necessary in trench excavations. Additionally, we do not recommend that open graded rock be used for pipe bedding or backfill because of the potential for piping erosion. The recommended bedding is clean sand having a sand equivalent not less than 30. Alternatively, 2-sack sandcement slurry can be used for the pipe bedding. If sand-cement slurry is used for pipe bedding to at least 1 foot over the top of the pipe, cutoff walls are not considered necessary. The need for cutoff walls should be further evaluated by the project civil engineer designing the pipeline Backfill Excavated material free of organic debris and rocks greater than 6 inches in any dimension are generally expected to be suitable for use as backfill. Imported material should not contain rocks greater than 4 inches in any dimension or organic debris. Imported material should have an expansion index of 20 or less. SCST should observe and, if appropriate, test proposed imported materials before they are delivered to the site. Backfill should be placed in lifts 8 inches or less in loose thickness, moisture conditioned to optimum moisture content or slightly above, and compacted to at least 90% relative compaction. All references to optimum moisture content and relative compaction in this report are based on ASTM D1557 test method. The upper 12 inches of soil beneath subgrade for pavements should be compacted to at least 95% relative compaction. We

13 City of Del Mar June 24, Sewer and Water Group 1 CIP, Water Project 1 SCST No P3.8-1 Del Mar, California Page 8 recommend that the soils in the top 24 inches below hardscape have an expansion index of 20 or less. SCST should observe and, if appropriate, test the soils to be used within this backfill zone. 6.6 CORROSIVITY Representative samples of the on-site soils were 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. 7 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 limited 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. 8 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 test pit 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

14 City of Del Mar June 24, Sewer and Water Group 1 CIP, Water Project 1 SCST No P3.8-1 Del Mar, California Page 9 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. 9 REFERENCES International Code Council (2012), 2013 California Building Code, Based on the 2012 International Existing Building Code, Effective Date: January 1, Public Works Standards, Inc. (2011), Greenbook Standard Specifications for Public Works Construction, 2012 Edition.

15 Project Site OpenStreetMap contributors. Tiles courtesy of MapQuest SCST, Inc. SITE VICINITY MAP 2016 Sewer & Water Group 1 Del Mar, California Date: June, 2016 By: JCU Job No.: P3.8-1 Figure: 1

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17 SL-1 B-1 Qvop TP-1 TP-2 TP-3 Tt SCST LEGEND: B-1 TP-3 Scale SCST, Inc. SL-1 Approximate Location of Geologic Contact Approximate Location of Boring Qvop Approximate Location of Test Pit Approximate location of Slope Log SUBSURFACE EXPLORATION MAP 2016 Sewer & Water Group 1 Del Mar, California Tt Very Old Paralic Deposits Torrey Sandstone Date: June, 2016 By: JCU Job No.: P3.8-1 Figure: 2

18 B-1 Qvop Tt SL-1 TP-3 TP-1 Tt Tt TP-2 B-4 SCST LEGEND: P-3 Scale SCST, Inc. SL-1 Approximate Location of Geologic Contact Approximate Location of Boring Qvop Approximate Location of Test Pit Tt Approximate location of Slope Log GEOLOGIC CROSS SECTION 2016 Sewer & Water Group 1 Del Mar, California Very Old Paralic Deposits Torrey Sandstone Date: June, 2016 By: JCU Job No.: P3.8-1 Figure: 3

19 APPENDIX I APPENDIX I SUBSURFACE EXPLORATION Our subsurface exploration consisted of drilling one boring to a depth of about 19½ feet below the existing ground surface using a truck-mounted drill rig equipped with a hollow stem auger, logging the bluff at the top of the slope, and excavating three test pits with hand tools on May 31, Figure 2 shows the approximate locations of the boring, slope log, and test pits. Our subsurface exploration was performed under the observation of an SCST geologist who also logged the borings and obtained samples of the materials encountered. Relatively undisturbed samples were obtained using a modified California (CAL) sampler, which is a ring-lined split tube sampler with a 3-inch outer diameter and 2½-inch inner diameter. Standard Penetration Tests (SPT) were performed using a 2-inch outer diameter and 1⅜-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 boring logs as Driving Resistance (blows/ft 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. Because the SPT sampler was driven with a cathead and rope, the driving resistance is representative of a 60% energy transfer ratio (N 60). Disturbed bulk samples were obtained from the SPT sampler and the drill cuttings. The soils are classified in accordance with the Unified Soil Classification System as illustrated on Figure I-1. A log of the boring is presented on Figure I-2. A log of the bluff is presented on Figure I-3, and logs of the test pits are presented on Figures I-4 through I-6.

20 SOIL DESCRIPTION SUBSURFACE EXPLORATION LEGEND UNIFIED SOIL CLASSIFICATION CHART GROUP SYMBOL TYPICAL NAMES I. COARSE GRAINED, more than 50% of material is larger than No. 200 sieve size. GRAVELS More than half of coarse fraction is larger than No. 4 sieve size but smaller than 3". CLEAN GRAVELS GRAVELS WITH FINES (Appreciable amount of fines) GW GP GM GC Well graded gravels, gravel-sand mixtures, little or no fines Poorly graded gravels, gravel sand mixtures, little or no fines. Silty gravels, poorly graded gravel-sand-silt mixtures. Clayey gravels, poorly graded gravel-sand, clay mixtures. SANDS CLEAN SANDS More than half of coarse fraction is smaller than No. 4 sieve size. SW SP SM SC Well graded sand, gravelly sands, little or no fines. Poorly graded sands, gravelly sands, little or no fines. Silty sands, poorly graded sand and silty mixtures. Clayey sands, poorly graded sand and clay mixtures. II. FINE GRAINED, more than 50% of material is smaller than No. 200 sieve size. SILTS AND CLAYS (Liquid Limit less than 50) SILTS AND CLAYS (Liquid Limit greater than 50) III. HIGHLY ORGANIC SOILS ML CL OL MH CH OH PT Inorganic silts and very fine sands, rock flour, sandy silt or clayeysilt-sand mixtures with slight plasticity. Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, silty clays, lean clays. Organic silts and organic silty clays or low plasticity. Inorganic silts, micaceous or diatomaceous fine sandy or silty soils, elastic silts. Inorganic clays of high plasticity, fat clays. Organic clays of medium to high plasticity. 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 - Standard Penetration Test sampler EI - Expansion Index MAX - Maximum Density GROUNDWATER SYMBOLS - Water level at time of excavation or as indicated - Water seepage at time of excavation or as indicated RV - R-Value SA - Sieve Analysis UC - Unconfined Compression RW - Response to Wetting SCST, Inc Sewer and Water Group 1 CIP, Water Project 1 Del Mar, California By: CJM Date: June, 2016 Job Number: P3.8-1 Figure: I-1

21 DEPTH (ft) USCS DRIVEN BULK DRIVING RESISTANCE (blows/ft of drive) MOISTURE CONTENT (%) DRY UNIT WEIGHT (pcf) LABORATORY TESTS LOG OF BORING B-1 Date Drilled: 5/31/2016 Logged by: CJM Equipment: CME-75 Project Manager: AKN Elevation (ft): 322 Depth to Groundwater (ft): Not encountered SAMPLES SUMMARY OF SUBSURFACE CONDITIONS N60 1 SM FILL (Qf): SILTY SAND, moderate brown, fine to medium grained, moist, loose to medium dense SM VERY OLD PARALIC DEPOSITS (Qvop): SANDSTONE, moderate yellowish-brown, fine to medium grained, moist, very dense, breaks down to silty sand. Orangish-brown. CAL SC CLAYEY SAND with GRAVEL, orangish-brown, fine to medium grained, moist, very dense. SPT 50/5" SM SILTY SAND with GRAVEL, orangish-brown, fine to medium grained, moist, very dense. SPT 50/6" Cobble encountered SM TORREY SANDSTONE (Tt): SANDSTONE, moderate yellowish-brown, fine to medium grained, moist, very dense, breaks down to silty sand. SPT 50/6" BORING TERMINATED AT 19½ FEET SCST, Inc Sewer and Water Group 1 CIP, Water Project 1 Del Mar, California By: CJM Date: June, 2016 Job Number: P3.8-1 Figure: I-2

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23 Abandoned Water Line Existing Water Line HORIZONTAL AND VERTICAL SCALE 1" = 4' (Qvop) 1 Silty Sandstone, Orangish-Brown with Vertical Streaks of Yellowish-Gray, Fine to Medium Grained, Non-Plastic, Massive, Moderately Fractured, Moderately Cemented, Oxidized, Medium Dense to Dense. 2 Conglomerate (1) Moderate Yellowish-Brown, Fine to Coarse Grained, Matrix Supported, Horizontal Embrication, Clasts up to 1.5 Inches, Moderately Cemented, Lightly Fractured, Oxidized Matrix, Medium Dense to Dense. Fining upward Sequence - Coarse Sand Above Gravel. 3 Silty Sandstone, Orangish-Brown, Fine Grained, Massive, Dense Unfractured, Moderately Cemented, Heavily Oxidized, Black Rootlets Positioned Vertically, Manganeze Staming, Horizontal Lenses of Moderate Yellowish-Brown Sandstone with Similar Cementation. 4 Conglomerate (2) Orangish-Brown, Moderate Brown, Moderate Yellowish-Brown, Fine to Coarse Grained, Primarily Matrix Supported, Poorly to Moderately Embricated, Lightly Fractured (Hairline), Oxidized, Multiple Fining upward Sequences, Moderately Cemented Clasts up to 5 Inches in Diameter. Medium Dense. 5 Sandstone, Moderate Yellowish-Brown, Weathered to Light Yellowish-Brown, Fine to Coarse Grained, Massive. Lightly to Moderately Oxidized, Moderately Cemented, Dense, Lightly Weathered, Lightly Fractured. SCST, Inc. SLOPE LOG Sewer and Water Group 1 Del Mar, California Date: June, 2016 By: JCU Job No.: P Figure: I-3

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25 LOG OF SLOPE SL-1 Date Drilled: 5/31/2016 Logged by: CJM Equipment: N/A Project Manager: AKN Elevation (ft): 322 Depth to Groundwater (ft): Not encountered DEPTH (ft) USCS SUMMARY OF SUBSURFACE CONDITIONS SAMPLES DRIVEN BULK DRIVING RESISTANCE (blows/ft of drive) N60 MOISTURE CONTENT (%) DRY UNIT WEIGHT (pcf) LABORATORY TESTS 1 SM VERY OLD PARALIC DEPOSITS (Qvop): SANDSTONE, orangish-brown, fine to medium grained, moist, medium dense to dense, moderately cemented, moderately weathered, massive, breaks down to silty sand SC CLAYEY SAND with GRAVEL, moderate yellowish-brown, fine to coarse grained, moist, medium dense to dense, moderately cemented, slightly to moderately weathered SM SM SANDSTONE, orangish-brown, fine grained, moist, dense, moderately cemented, slightly weathered, massive, breaks down to silty sand. SILTY SAND with GRAVEL and COBBLE, orangish-brown and moderate brown, fine to coarse grained, moist, medium dense, moderately cemented, slightly to moderately weathered, cobble up to 6 inches present. COLLUVIUM (Qcol): SILTY SAND, moderate brown, fine to medium grained, dry to moist, loose, collapsible. SLOPE LOG TERMINATED AT 15 FEET SCST, Inc Sewer and Water Group 1 CIP Water Project 1 Del Mar, California By: CJM Date: June, 2016 Job Number: P3.8-1 Figure: I-3

26 LOG OF TEST PIT TP-1 Date Drilled: 5/31/2016 Logged by: CJM Equipment: Hand Tools Project Manager: AKN Elevation (ft): 300 Depth to Groundwater (ft): Not encountered DEPTH (ft) USCS SUMMARY OF SUBSURFACE CONDITIONS SAMPLES DRIVEN BULK MOISTURE CONTENT (%) DRY UNIT WEIGHT (pcf) LABORATORY TESTS ½ 1 3- inches of debris and gravel. SP- TORREY SANDSTONE (Tt): SANDSTONE, moderate yellowish-brown, fine to SM medium grained, moist, dense, moderately cemented, breaks down to poorly graded sand with silt. BORING TERMINATED AT 1 FOOT ON SANDSTONE 1½ 2 2½ 3 3½ 4 4½ 5 5½ 6 6½ 7 7½ 8 8½ 9 9½ 10 SCST, Inc Sewer and Water Group 1 CIP Water Project 1 Del Mar, California By: Job Number: CJM P3.8-1 June, 2016 I-4

27 LOG OF TEST PIT TP-2 Date Drilled: 5/31/2016 Logged by: CJM Equipment: Hand Tools Project Manager: AKN Elevation (ft): 230 Depth to Groundwater (ft): Not encountered DEPTH (ft) USCS SUMMARY OF SUBSURFACE CONDITIONS SAMPLES DRIVEN BULK MOISTURE CONTENT (%) DRY UNIT WEIGHT (pcf) LABORATORY TESTS ½ 1 SM TORREY SANDSTONE (Tt): SANDSTONE, moderate yellowish-brown, fine to medium grained, moist, medium dense to dense, moderately cemented, breaks down to silty sand. BORING TERMINATED AT 1 FOOT ON SANDSTONE 1½ 2 2½ 3 3½ 4 4½ 5 5½ 6 6½ 7 7½ 8 8½ 9 9½ 10 SCST, Inc Sewer and Water Group 1 CIP Water Project 1 Del Mar, California By: Job Number: CJM P3.8-1 June, 2016 I-5

28 LOG OF TEST PIT TP-3 Date Drilled: 5/31/2016 Logged by: CJM Equipment: Hand Tools Project Manager: AKN Elevation (ft): 180 Depth to Groundwater (ft): Not encountered DEPTH (ft) USCS SUMMARY OF SUBSURFACE CONDITIONS SAMPLES DRIVEN BULK MOISTURE CONTENT (%) DRY UNIT WEIGHT (pcf) LABORATORY TESTS ½ 1 SM TORREY SANDSTONE (Tt): SANDSTONE, moderate yellowish-brown, fine to medium grained, moist, dense, moderately cemented, breaks down to silty sand. BORING TERMINATED AT 1 FOOT ON SANDSTONE 1½ 2 2½ 3 3½ 4 4½ 5 5½ 6 6½ 7 7½ 8 8½ 9 9½ 10 SCST, Inc Sewer and Water Group 1 CIP Water Project 1 Del Mar, California By: Job Number: CJM P3.8-1 June, 2016 I-6

29 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 two soil samples in accordance with ASTM D422. Figures II-1 through II-3 present the test results. ATTERBERG LIMITS: The Atterberg limits were determined on one sample in accordance with ASTM D4318. Figure II-2 presents the test results. CORROSIVITY: Corrosivity tests were performed on two soil samples. The ph and minimum resistivity were determined in general 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 II-4 presents the test results. DIRECT SHEAR: Direct shear tests were performed on one sample in accordance with ASTM D3080. The shear stress was applied at a constant rate of strain of inch per minute. Figure II-5 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.

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31 U.S. Standard Sieve Sizes 100 6" 3" 1-½" 3/4" 3/8" #4 #8 #10 #16 #30 #40 #50 #100 # Percent Finer by Weight Grain Size in Millimeters Cobbles Coarse Gravel Fine Sand Coarse Medium Fine Silt or Clay SAMPLE LOCATION UNIFIED SOIL CLASSIFICATION: SM B-1 at 3 to 8 feet DESCRIPTION SILTY SAND ATTERBERG LIMITS LIQUID LIMIT PLASTIC LIMIT PLASTICITY INDEX SCST, Inc. By: Job Number: 2016 Sewer and Water Group 1 CIP, Water Project 1 Del Mar, California CJM P3.8-1 Date: Figure: June, 2016 II-1

32 U.S. Standard Sieve Sizes 100 6" 3" 1-½" 3/4" 3/8" #4 #8 #10 #16 #30 #40 #50 #100 # Percent Finer by Weight Grain Size in Millimeters Cobbles Coarse Gravel Fine Sand Coarse Medium Fine Silt or Clay SAMPLE LOCATION B-1 at 8½ to 10 feet UNIFIED SOIL CLASSIFICATION: DESCRIPTION SC CLAYEY SAND with GRAVEL ATTERBERG LIMITS LIQUID LIMIT PLASTIC LIMIT PLASTICITY INDEX SCST, Inc. By: Job Number: 2016 Sewer and Water Group 1 CIP, Water Project 1 Del Mar, California CJM P3.8-1 Date: Figure: June, 2016 II-2

33 U.S. Standard Sieve Sizes 100 6" 3" 1-½" 3/4" 3/8" #4 #8 #10 #16 #30 #40 #50 #100 # Percent Finer by Weight Grain Size in Millimeters Cobbles Coarse Gravel Fine Sand Coarse Medium Fine Silt or Clay SAMPLE LOCATION B-1 at 18½ to 19½ feet UNIFIED SOIL CLASSIFICATION: DESCRIPTION SM SILTY SAND ATTERBERG LIMITS LIQUID LIMIT PLASTIC LIMIT PLASTICITY INDEX SCST, Inc Sewer and Water Group 1 CIP, Water Project 1 Del Mar, California By: CJM Date: June, 2016 Job Number: P3.8-1 Figure: II-3

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35 SAMPLE B-1 at 3 to 8 feet CORROSION TEST RESULTS RESISTIVITY, ph, SOLUBLE CHLORIDE and SOLUBLE SULFATE RESISTIVITY (Ω-cm) ph CHLORIDE (%) SULFATE (%) Sulfate Exposure Negligible Moderate Severe ACI Building Code Requirements for Structural Concrete Table Requirements for Concrete Exposed to Sulfate-Containing Solutions Water-Soluble Sulfate (SO 4 ) in Soil Percentage by Weight Cement Type Maximum Water- Cementitious Materials Ratio, By Weight, Normal Weight Aggregate Concrete II,IP(MS),IS(MS), P(MS), V 0.45 Minimum f'c, Normal-Weight and Lightweight Aggregate Concrete, psi Very Severe Over 2.00 V plus pozzolan Classification of Corrosive Environment 2 ph CHLORIDE CONTENT (%) SULFATE CONTENT (%) Based on California Department of Transportation, Division of Engineering Services, Materials Engineering and Testing Services, Corrosion and Structural Concrete, Field Investigation Branch, Corrosion Guidelines, Version 2.0, November 2012 SCST, Inc. By: Job No.: 2016 Sewer and Water Group 1 CIP, Water Project 1 Del Mar, California CJM Date: June, P3.8-1 Figure: II-4

36 Shear Stress (psf) Confining Pressure (psf) Shear Strain (%) Peak Strength 20 degrees, 1900 psf Ultimate Strength degrees, 1950 psf Shear Stress (psf) Confining Pressure (psf) SAMPLE ID: B-1 at 3½ to 5 feet SILTY SAND, Moderate yellowish-brown Peak Ultimate Φ 20 o 17 o c 1900 psf 1950 psf Initial Final NOTES: Insitu γ d pcf pcf Strain Rate: in/min w c 13.9 % 18.0 % Sample was consolidated and drained Saturation 85 % 109 % 2016 Sewer and Water Group 1 CIP, Water Project 1 Del Mar, California By: CJM Date: Job Number: P3.8-1 Figure: II-5 SCST Inc. June, 2016