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5529; POINSETTIA LIFT STATION STANDBY PUMP SYSTEM - EMERGENCY STORAGE BASIN POINSETTIA LIFT STATION; GEOTECHINICAL EVALUATION; EMERGENCY STORAGE BASIN; 2015-06-10
GEOTECHNICAL EVALUATION EMERGENCY STORAGE BASIN POINSETTIA LIFT STATION CARLSBAD, CALIFORNIA PREPARED FOR: City of Carlsbad 1635 Faraday Avenue Carlsbad, California 92008 PREPARED BY: Ninyo & Moore Geotechnical and Environmental Sciences Consultants 5710 Ruffin Road San Diego, California 92123 June 10, 2015 Project No. 107544009 June 10, 2015 Project No. 107549009 Mr. Mark Biskup City of Carlsbad 1635 Faraday Avenue Carlsbad, California 92008 Subject: Geotechnical Evaluation Emergency Storage Basin Poinsettia Lift Station Carlsbad, California Dear Mr. Biskup: In accordance with your authorization, we have performed a geotechnical evaluation for the pro- posed Emergency Storage Basin at the City of Carlsbad’s Poinsettia Lift Station in Carlsbad, California. This report presents our geotechnical findings, conclusions, and recommendations regarding the proposed project. Our report was prepared in accordance with the subconsultant agreement dated April 17, 2015. We appreciate the opportunity to be of service on this project. Sincerely, NINYO & MOORE William Morrison, PE, GE Senior Engineer Gregory T. Farrand, PG, CEG Principal Geologist BTM/WRM/GTF/gg Distribution: (1) Addressee (via e-mail) Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc i TABLE OF CONTENTS Page 1. INTRODUCTION ....................................................................................................................1 2. SCOPE OF SERVICES ............................................................................................................1 3. SITE AND PROJECT DESCRIPTION ...................................................................................1 4. FIELD EXPLORATION AND LABORATORY TESTING ..................................................2 5. GEOLOGY AND SUBSURFACE CONDITIONS .................................................................2 5.1. Regional Geologic Setting ............................................................................................3 5.2. Site Geology .................................................................................................................3 5.2.1. Fill .......................................................................................................................4 5.2.2. Alluvium .............................................................................................................4 5.2.3. Santiago Formation .............................................................................................4 5.3. Groundwater .................................................................................................................4 6. GEOLOGIC HAZARDS ..........................................................................................................5 6.1. Faulting and Seismicity ................................................................................................5 6.1.1. Ground Rupture ...................................................................................................5 6.1.2. Ground Motion ....................................................................................................5 6.1.3. Liquefaction ........................................................................................................6 6.2. Landsliding ...................................................................................................................7 7. CONCLUSIONS AND RECOMMENDATIONS ...................................................................7 8. RECOMMENDATIONS ..........................................................................................................8 8.1. Earthwork .....................................................................................................................8 8.1.1. Pre-Construction Conference ..............................................................................8 8.1.2. Site Preparation ...................................................................................................8 8.1.3. Temporary Excavations ......................................................................................9 8.1.4. Shoring and Braced Excavations ........................................................................9 8.1.5. Construction Dewatering ..................................................................................10 8.1.6. Remedial Earthwork .........................................................................................11 8.1.7. Mitigation of Unstable Excavation Bottoms .....................................................11 8.1.8. Materials for Fill ...............................................................................................12 8.1.9. Compacted Fill ..................................................................................................12 8.1.10. Lateral Pressures for Thrust Blocks ..................................................................13 8.1.11. Pipe Bedding and Modulus of Soil Reaction (E') .............................................13 8.1.12. Pipe Zone Backfill ............................................................................................14 8.1.13. Utility Trench Backfill ......................................................................................14 8.1.14. Drainage ............................................................................................................15 8.2. Seismic Design Parameters .........................................................................................16 8.3. Foundations .................................................................................................................16 8.3.1. Mat Foundations ...............................................................................................16 8.3.2. Lateral Resistance .............................................................................................17 8.3.3. Static Settlement ...............................................................................................18 Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc ii 8.4. Underground Structures ..............................................................................................18 8.5. Uplift and Special Design Considerations ..................................................................18 8.6. Concrete Flatwork ......................................................................................................19 8.7. Pavements ...................................................................................................................19 8.8. Corrosivity ..................................................................................................................20 8.9. Concrete ......................................................................................................................21 9. PLAN REVIEW AND CONSTRUCTION OBSERVATION ...............................................21 10. LIMITATIONS .......................................................................................................................22 11. REFERENCES .......................................................................................................................24 Table Table 1 – 2013 California Building Code Seismic Design Criteria ...............................................16 Figures Figure 1 – Site Location Figure 2 – Boring Locations Figure 3 – Geology Figure 4 – Fault Locations Figure 5 – Lateral Earth Pressures for Temporary Cantilevered Shoring below Groundwater Figure 6 – Lateral Earth Pressures for Braced Excavation Below Groundwater (Stiff Clay) Figure 7 – Thrust Block Lateral Earth Pressure Diagram Figure 8 – Lateral Earth Pressures for Underground Structures Figure 9 – Uplift Resistance Diagram for Underground Structures Appendices Appendix A – Boring Logs Appendix B – Laboratory Testing Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc 1 1. INTRODUCTION In accordance with your request and our agreement dated April 17, 2015, we have performed a ge- otechnical evaluation for the proposed Poinsettia Lift Station Emergency Storage Basin in Carlsbad, California (Figure 1). This report presents our conclusions regarding the geotechnical conditions at the subject site and our recommendations for the design of this project. 2. SCOPE OF SERVICES The scope of our geotechnical services included the following: Review of readily available published and in-house geotechnical literature, preliminary site plan, topographic maps, geologic maps, fault maps, and stereoscopic aerial photographs. Performing a field reconnaissance to observe existing site conditions and to locate and mark proposed exploratory boring locations. Performing subsurface exploration consisting of drilling, logging, and sampling of two ex- ploratory borings in the project area. Bulk and relatively undisturbed drive samples of soil were collected at selected intervals from the borings and transported to our in-house ge- otechnical laboratory for testing. Performing geotechnical laboratory testing on selected soil samples to evaluate soil parame- ters for design purposes that included in-situ dry density and moisture content, gradation, Atterberg Limits, consolidation, direct shear, R-value, and soil corrosivity. Geotechnical evaluation of field and laboratory data. Preparation of this report presenting our findings, conclusions, and recommendations re- garding the geotechnical design and construction of the project. 3. SITE AND PROJECT DESCRIPTION The City of Carlsbad’s Poinsettia Lift Station is located on the north side of Poinsettia Lane, east of Alicante Road in Carlsbad, California (Figure 1). The site is bounded by a residential development to the north and east, Poinsettia Lane to the south, and an open natural vegetation area to the west. The site is relatively flat and covered with asphalt concrete pavement. Two existing buildings, a pump structure, piping and other associated improvements are located at the site. The site elevation Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc 2 is approximately 110 feet above mean sea level (MSL). Surface drainage is generally by sheet flow to the south towards Poinsettia Lane. Based on our review of project information, along with our communications with Kennedy Jenks Consultants, it is our understanding that the proposed project will include construction of a new emergency storage basin, a trailer-mounted bypass pump, associated piping at the site, and other appurtenances (Figure 2). We understand that the new improvements including the emergency storage basin will be integrated with the existing lift station. Our review of the project information (Carlsbad, undated) indicates that the proposed emergency storage basin is to be constructed at depths on the order of 18 feet below existing grade, while the pipelines and other improvements will be constructed at depths less than that for the emergency storage basin. 4. FIELD EXPLORATION AND LABORATORY TESTING Our subsurface exploration was conducted on May 6, 2015 and consisted of drilling, logging, and sampling two exploratory borings. The borings were drilled to depths of up to 46.5 feet be- low existing grades with a truck mounted drill rig equipped with hollow stem augers. Soil samples were obtained at selected intervals from the borings. The samples were then transported to our in-house geotechnical laboratory for testing. The approximate locations of the exploratory borings are shown on Figure 2. Logs of the borings are included in Appendix A. Laboratory testing of representative soil samples included in-situ dry density and moisture content, gradation, Atterberg Limits, consolidation, direct shear, R-value, and soil corrosivity. The results of the in-situ dry density and moisture content tests are presented on the boring logs in Appendix A. The results of the other laboratory tests described above are presented in Appendix B. 5. GEOLOGY AND SUBSURFACE CONDITIONS Our findings regarding regional and site geology and groundwater conditions at the project site are provided in the following sections. Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc 3 5.1. Regional Geologic Setting The project area is situated in the coastal section of the Peninsular Ranges Geomorphic Prov- ince. This geomorphic province encompasses an area that extends approximately 900 miles from the Transverse Ranges and the Los Angeles Basin south to the southern tip of Baja Cali- fornia (Norris and Webb, 1990; Harden, 2004). The province varies in width from approximately 30 to 100 miles. In general, the province consists of rugged mountains under- lain by Jurassic metavolcanic and metasedimentary rocks, and Cretaceous igneous rocks of the southern California batholith. The portion of the province in San Diego County that includes the project area is underlain by Tertiary and Quaternary sedimentary rock (Figure 3). The Peninsular Ranges Province is traversed by a group of sub-parallel faults and fault zones trending roughly northwest. Several of these faults, which are shown on Figure 4, are considered active faults. The Elsinore, San Jacinto, and San Andreas faults are active fault systems located northeast of the project area and the Rose Canyon, Coronado Bank, San Diego Trough, and San Clemente faults are active faults located west of the project area. The Rose Canyon Fault Zone, the nearest active fault system, has been mapped approximately 7 miles west of the project site. Major tectonic activity associated with these faults within this regional tectonic framework consists pri- marily of right-lateral, strike-slip movement. Further discussion of faulting relative to the site is provided in the Faulting and Seismicity and Seismic Hazards section of this report. 5.2. Site Geology Geologic units encountered during our subsurface evaluation include fill, alluvium, and San- tiago Formation. Generalized descriptions of the earth units encountered are provided in the subsequent sections. Additional descriptions of the subsurface units are provided on the bor- ing logs in Appendix A. Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc 4 5.2.1. Fill Fill was encountered in both of our borings beneath existing pavements to depths of up to 8 feet. As encountered during our subsurface exploration, the fill consists of gray, moist, very stiff, silty clay. Geotechnical literature documenting the place- ment/compaction of the fill was not available for our review. 5.2.2. Alluvium Alluvium was encountered in our borings beneath the fill and was observed to extend to depths of up to 29 feet. As encountered in our exploratory borings, the alluvium gener- ally consists of various shades of gray and brown, moist to wet, very stiff to hard, silty clay, sandy clay, and fat clay. 5.2.3. Santiago Formation Materials comprising the Santiago Formation was encountered in both of our borings underlying the alluvium and was observed to the total depths explored of up to 46½ feet. As encountered, the Santiago Formation generally consists of various shades of gray to brown, wet, weakly to moderately cemented silty sandstone and moderately indurated sandy siltstone. 5.3. Groundwater Groundwater was encountered during our subsurface exploration in our boring B-1 at a depth of approximately 22 feet and in our boring B-2 at a depth of approximately 12 feet. Relatively high moisture contents measured within samples obtained from depths shallower than the observed groundwater surface indicate that the static groundwater surface could be at depths on the order of 5 feet or less. Fluctuations in the groundwater level and perched conditions typically occur due to variations in precipitation, ground surface topography, sub- surface stratification, irrigation, and other factors. Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc 5 6. GEOLOGIC HAZARDS In general, hazards associated with seismic activity include strong ground motion, ground surface rupture, and liquefaction. These considerations and other geologic hazards such as landsliding are discussed in the following sections. 6.1. Faulting and Seismicity The project area is considered to be seismically active. Based on our review of the refer- enced geologic maps as well as on our geologic field mapping, the subject site is not underlain by known active or potentially active faults (i.e., faults that exhibit evidence of ground displacement in the last 11,000 years and 2,000,000 years, respectively). However, the site is located in a seismically active area, as is the majority of southern California, and the potential for strong ground motion is considered significant during the design life of the proposed structure. The nearest known active fault is the Rose Canyon Fault, located ap- proximately 7 miles west of the site (Figure 4). In general, hazards associated with seismic activity include ground surface rupture, strong ground motion, ground surface rupture, liquefaction, and seismically induced settlement. These hazards are discussed in the following sections. 6.1.1. Ground Rupture There are no known active faults crossing the subject site, and the potential for ground rupture due to faulting is considered low. The potential for surface ground cracking re- lated to shaking from distant events is also considered low. 6.1.2. Ground Motion The 2013 California Building Code (CBC) specifies that the Risk-Targeted, Maximum Considered Earthquake (MCER) ground motion response accelerations be used to eval- uate seismic loads for design of buildings and other structures. The MCER ground motion response accelerations are based on the spectral response accelerations for 5 percent damping in the direction of maximum horizontal response and incorporate a Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc 6 target risk for structural collapse equivalent to 1 percent in 50 years with deterministic limits for near-source effects. The horizontal peak ground acceleration (PGA) that cor- responds to the MCER for the site was calculated as 0.453g using the United States Geological Survey (USGS, 2013) seismic design tool (web-based). Spectral response acceleration parameters, consistent with the 2013 CBC, are also provided in Section 8.2. for the evaluation of seismic loads on buildings and other structures. The 2013 CBC specifies that the potential for liquefaction and soil strength loss be evaluated, where applicable, for the Maximum Considered Earthquake Geometric Mean (MCEG) peak ground acceleration with adjustment for site class effects in accordance with the American Society of Civil Engineers (ASCE) 7-10 Standard. The MCEG peak ground acceleration is based on the geometric mean peak ground acceleration with a 2 percent probability of exceedance in 50 years. The MCEG peak ground acceleration with adjustment for site class effects (PGAM) was calculated as 0.442g using the USGS (USGS, 2013) seismic design tool that yielded a mapped MCEG peak ground accelera- tion of 0.403g for the site and a site coefficient (FPGA) of 1.097 for Site Class D. 6.1.3. Liquefaction Liquefaction is the phenomenon in which loosely deposited granular soils with silt and clay contents of less than approximately 35 percent and non-plastic silts located below the water table undergo rapid loss of shear strength when subjected to strong earth- quake-induced ground shaking. Ground shaking of sufficient duration results in the loss of grain-to-grain contact due to a rapid rise in pore water pressure, and causes the soil to behave as a fluid for a short period of time. Liquefaction is known generally to occur in saturated or near-saturated cohesionless soils at depths shallower than 50 feet below the ground surface. Factors known to influence liquefaction potential include composition and thickness of soil layers, grain size, relative density, groundwater level, degree of saturation, and both intensity and duration of ground shaking. Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc 7 As noted above in Section 5.2.2 and in our exploratory borings (Appendix A), the en- countered portions of the alluvium were observed to generally consist of silty clay, sandy clay, and fat clay. Based on guidelines outlined by Bray and Sancio (2006), we conclude that the alluvium is not susceptible to liquefaction or seismic induced settle- ment, due to its clayey nature. 6.2. Landsliding No landslides or indications of deep-seated landslides were noted underlying the project site dur- ing our field exploration or our review of available geologic literature and topographic maps. 7. CONCLUSIONS AND RECOMMENDATIONS Based on our geotechnical evaluation, it is our opinion that construction of the proposed project is feasible from a geotechnical standpoint, provided the following conclusions and recommenda- tions are incorporated into the design and construction of the project. The following includes geotechnical considerations and conclusions for the project: The project area is underlain by fill, alluvium, and the Santiago Formation. The existing fill soils are not considered suitable for structural support of the proposed improvements in their current condition. Groundwater was encountered during our subsurface exploration at a depth of approximate- ly 12 feet below the ground surface. The relatively high moisture contents measured in samples obtained from depths shallower than the observed groundwater surface suggest that the static groundwater level could be at a depth of 5 feet or less. Groundwater will be a con- straint during construction and the contractor should anticipate dewatering prior to the excavation for the emergency storage basin and its associated improvements. Wet materials were encountered in our exploratory borings. Therefore, unstable excavation bottoms and caving soils should be anticipated. The contractor should anticipate and be pre- pared to address these conditions. Wet soils encountered on the site will require additional handling prior to their being reused as fill. Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc 8 Based on the results of our exploratory borings and our experience with similar soils, it is our opinion that the on-site fill and alluvial materials can be excavated using heavy duty earthmoving equipment in good working condition. The results of our subsurface evaluation indicate that the alluvial soils that underlie the site are not susceptible to liquefaction or seismically induced settlement. We anticipate that the new emergency storage basin, trailer mounted bypass pump, and other improvements will be constructed on mat foundations. The mat foundations can be expected to tolerate estimated total and differential settlements, as well as buoyant/uplift forces, pro- vided they are designed in accordance with the recommendations contained herein. Based on the laboratory test results, ACI 318, and Caltrans (2012) criteria, the on site soils are considered corrosive. 8. RECOMMENDATIONS Based on our understanding of the project, the following recommendations are provided for the design and construction of the proposed project. 8.1. Earthwork In general, earthwork should be performed in accordance with the recommendations presented in this report. Ninyo & Moore should be contacted for questions regarding the recommenda- tions or guidelines presented herein. 8.1.1. Pre-Construction Conference We recommend that a pre-construction conference be held. The owner and/or their rep- resentative, the governing agencies’ representatives, the civil engineer, the architect, Ninyo & Moore, and the contractor should be in attendance to discuss the work plan and project schedule and earthwork requirements. 8.1.2. Site Preparation Prior to performing excavations or other earthwork, the project site should be cleared of abandoned utilities (if present) and stripped of rubble, debris, vegetation, any loose, wet, or otherwise unstable soils, as well as surface soils containing organic material. Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc 9 Materials generated from the clearing operations should be removed from the site and disposed of at a legal dumpsite away from the project area. 8.1.3. Temporary Excavations For temporary excavations, we recommend that the following Occupational Safety and Health Administration (OSHA) soil classifications be used: Fill Type C Alluvium and Santiago Formation Type B Upon making the excavations, the soil classifications and excavation performance should be evaluated in the field by a competent person in accordance with the OSHA regulations. Temporary excavations should be constructed in accordance with OSHA recommenda- tions. For trench or other excavations, OSHA requirements regarding personnel safety should be met using appropriate shoring (including trench boxes) or by laying back the slopes to no steeper than 1.5:1 (horizontal to vertical) within the fill or 1:1 within the allu- vium. Temporary excavations that encounter seepage may be shored or stabilized by placing sandbags or gravel along the base of the seepage zone. Excavations encountering seepage should be evaluated on a case-by-case basis. On-site safety of personnel is the re- sponsibility of the contractor. 8.1.4. Shoring and Braced Excavations We anticipate that shoring systems will be installed for the site excavations. Shoring sys- tems will be constructed through fill and alluvial materials. The shoring system should be designed using the lateral earth pressures shown on Figure 5 for cantilevered shoring and Figure 6 for braced shoring. The recommended design pressures are based on the assumptions that the shoring system is constructed without raising the ground surface elevation behind the shoring, that there are no surcharge loads, such as soil stockpiles and construction materials, that no loads act above a 1:1 plane extending up and back from the base of the sheet pile system, and that the shored excavations do not extend Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc 10 deeper than 20 feet. The contractor should include the effect of any surcharge loads on the lateral pressures against the sheet pile wall. Settlement of the ground surface may occur behind the shoring wall during excavation. The amount of settlement depends heavily on the type of shoring system, the shoring con- tractor’s workmanship, and soil conditions. We recommend that structures/improvements in the vicinity of the planned shoring installation be reviewed with regard to foundation support and tolerance to settlement. To reduce the potential for distress to adjacent im- provements, we recommend that the shoring system be designed to reduce the ground settlement behind the shoring system to ½-inch or less. Possible causes of settlement that should be addressed include settlement during shoring installation, excavations, construc- tion vibrations, dewatering, and removal of the support system. The contractor should retain a qualified and experienced engineer to design the shoring system, evaluate the adequacy of these parameters and provide modifications for the de- sign. Shoring plans should be reviewed by the design engineer. We recommend that the contractor take appropriate measures to protect workers. OSHA requirements pertaining to worker safety should be observed. 8.1.5. Construction Dewatering During our subsurface exploration, groundwater was encountered at approximately 12 feet bgs in close proximity of the proposed lift station location. Results of our labora- tory testing suggest that the static groundwater level could be at depths of 5 feet or less. As previously discussed, fluctuations in the groundwater levels may occur at the site. Dewatering measures during excavation operations (including those for the lift station and associated vaults and utility trenches) should be prepared by the contractor’s engi- neer and reviewed by the design engineer. Considerations for construction dewatering should include anticipated drawdown, piping of soils, volume of pumping, potential for settlement, and groundwater discharge. As such, it may be prudent to photo-document structures and settlement sensitive improvements that are adjacent to the area of pro- Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc 11 posed construction prior to dewatering. Disposal of groundwater should be performed in accordance with guidelines of the Regional Water Quality Control Board (RWQCB). 8.1.6. Remedial Earthwork In those areas of the site where slabs-on-grade and shallow foundations are planned, we recommend that the existing fill soils be removed and replaced with compacted fill. Based on the results of our subsurface exploration, we anticipate that the depths of these removals could extend 8 feet or more below the existing ground surface In general, remedial grading should extend 5 feet or more beyond the outer edge of the structure footprint, as practical. Ninyo & Moore should observe the excavations prior to filling to evaluate the need for deeper removals. Deeper removals may be needed at specific locations if loose, compressi- ble, or otherwise unsuitable materials are exposed during grading. The removals should be replaced with compacted fill in accordance with this report. Excavations for the emergency storage basin and other underground improvements are anticipated to expose soft and wet materials after dewatering. Therefore, we recommend that the excavation be overexcavated a depth of approximately 2 feet below the pro- posed subgrade elevation. The overexcavated material should be replaced with compacted fill in accordance with Section 8.1.9 to a depth of approximately 1 foot be- low subgrade elevation, unless unstable conditions are encountered. We recommend that a 1-foot-thick crushed rock or lean concrete base course be placed at the bottom of the excavation (i.e., on top of the compacted fill) prior to construction of the foundation to provide a working surface. 8.1.7. Mitigation of Unstable Excavation Bottoms We anticipate that some of the bottoms of the excavations will be below the groundwa- ter and will be unstable. In general, unstable bottom conditions may be mitigated by overexcavating the excavation bottom to suitable depths (as evaluated in the field by Ninyo & Moore’s representative) and replacing with gravel wrapped with a geosynthet- Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc 12 ic filter fabric. Specific recommendations for stabilizing excavation bottoms should be based on evaluation in the field by Ninyo & Moore at the time of construction. 8.1.8. Materials for Fill On-site soils with an organic content of less than approximately 3 percent by volume (or 1 percent by weight) are considered suitable for reuse as fill. Fill material should gener- ally not contain rocks or lumps over approximately 4 inches, and generally not more than approximately 30 percent larger than ¾-inch. Utility trench backfill material should not contain rocks or lumps over approximately 3 inches in general. Soils classified as silts or clays should not be used for backfill in the pipe zone. Larger chunks, if generat- ed during excavation, may be broken into acceptably sized pieces or disposed of off site. Imported fill material, if needed for the project, should generally be granular soils with a very low to low expansion potential (i.e., an EI of 50 or less as evaluated by the ASTM Interna- tional [ASTM] Test Method D 4829). Import material should also be non-corrosive in accordance with the Caltrans (2012) corrosion guidelines. Materials for use as fill should be evaluated by Ninyo & Moore’s representative prior to filling or importing 8.1.9. Compacted Fill Prior to placement of compacted fill, the contractor should request an evaluation of the exposed ground surface by Ninyo & Moore. Unless otherwise recommended, the ex- posed ground surface should then be scarified to a depth of approximately 8 inches and moisture conditioned by wetting or aeration to generally above the optimum moisture content. The scarified materials should then be compacted to 90 percent of their modi- fied Proctor density as evaluated by ASTM D 1557. The evaluation of compaction by the geotechnical consultant should not be considered to preclude any requirements for observation or approval by governing agencies. It is the contractor's responsibility to notify this office and the appropriate governing agency when project areas are ready for observation, and to provide reasonable time for that review. Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc 13 Fill materials should be moisture conditioned to generally above the laboratory opti- mum moisture content prior to placement. The optimum moisture content will vary with material type and other factors. Moisture conditioning of fill soils should be generally consistent within the soil mass. Prior to placement of additional compacted fill material following a delay in the grading operations, the exposed surface of previously compacted fill should be prepared to receive fill. Preparation may include scarification, moisture conditioning, and recompaction. Compacted fill should be placed in horizontal lifts of approximately 8 inches in loose thick- ness. Prior to compaction, each lift should be moisture conditioned to generally above the laboratory optimum, mixed, and then compacted by mechanical methods, using sheepsfoot rollers, multiple-wheel pneumatic-tired rollers or other appropriate compacting rollers, to 90 percent of its modified Proctor density as evaluated by ASTM D 1557. Successive lifts should be treated in a like manner until the desired finished grades are achieved. 8.1.10. Lateral Pressures for Thrust Blocks Thrust restraint for buried pipelines may be achieved by transferring the thrust force to the soil outside the pipe through a thrust block. Thrust blocks may be designed using the lateral passive earth pressures presented on Figure 7. Thrust blocks should be backfilled with granular backfill material, and compacted in accordance with recommendations presented in this report. 8.1.11. Pipe Bedding and Modulus of Soil Reaction (E') It is our recommendation that the new pipelines (pipes), where constructed in open ex- cavations, be supported on 6 or more inches of granular bedding material overlying prepared subgrade in accordance with the recommendations presented in Section 8.1.6. Granular pipe bedding should be provided to distribute vertical loads around the pipe. Bedding material and compaction requirements should be in accordance with this re- port. Pipe bedding typically consists of graded aggregate with a coefficient of uniformity of three or greater. Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc 14 The modulus of soil reaction (E’) is used to characterize the stiffness of soil backfill placed at the sides of buried flexible pipes for the purpose of evaluating deflection caused by the weight of the backfill over the pipe (Hartley and Duncan, 1987). A soil reaction modulus of 1,200 pounds per square inch (psi) may be used for an excavation depth of up to approximately 5 feet when backfilled with granular soil compacted to a relative compaction of 90 percent as evaluated by the ASTM D 1557. A soil reaction modulus of 1,800 psi may be used for trenches deeper than 5 feet. If on site clayey soils are utilized for pipe backfill, a soil reaction modulus of 1,000 psi may be used for an excavation depth of up to approximately 5 feet. A soil reaction mod- ulus of 1,400 psi may be used for trenches deeper than 5 feet that are backfilled with on site clayey soils. 8.1.12. Pipe Zone Backfill The pipe zone backfill should be placed on top of the pipe bedding material and extend to 1 foot or more above the top of the pipe in accordance with the recent edition of the Standard Specifications for Public Works Construction (“Greenbook”). Pipe zone back- fill should have a Sand Equivalent (SE) of 30 or greater, and be placed around the sides and top of the pipe. Special care should be taken not to allow voids beneath and around the pipe. Compaction of the pipe zone backfill should proceed up both sides of the pipe. It has been our experience that the voids within a crushed rock material are sufficiently large to allow fines to migrate into the voids, thereby creating the potential for sinkholes and depressions to develop at the ground surface. If open-graded gravel is utilized as pipe zone backfill, this material should be wrapped with a geosynthetic filter fabric. 8.1.13. Utility Trench Backfill Based on our subsurface evaluation, the on-site earth materials should be generally suitable for re-use as trench backfill provided they are free of organic material, clay lumps, debris, and rocks greater than approximately 3 inches in diameter. Fill should be moisture- conditioned to generally above the laboratory optimum. Trench backfill should be compact- Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc 15 ed to 90 percent of its modified Proctor density as evaluated by ASTM D 1557 except for the upper 12 inches of the backfill in pavement or flatwork areas that should be compacted to 95 percent of its modified Proctor density as evaluated by ASTM D 1557. Lift thickness for backfill will depend on the type of compaction equipment utilized, but fill should gener- ally be placed in lifts not exceeding 8 inches in loose thickness. Special care should be exercised to avoid damaging the pipe during compaction of the backfill. 8.1.14. Drainage Roof and pad drainage should be conveyed away from structures to suitable discharge areas by nonerodible devices (e.g., gutters, downspouts, concrete swales, etc.). Posi- tive drainage adjacent to structures should be established and maintained. Positive drainage may be accomplished by providing drainage away from the foundations of the structure at a gradient of 2 percent or steeper for a distance of 5 feet or more out- side the building perimeter, and further maintained by a graded swale leading to an appropriate outlet, in accordance with the recommendations of the project civil engi- neer and/or landscape architect. Surface drainage on the site should be provided so that water is not permitted to pond. A gradient of 2 percent or steeper should be maintained over the pad area and drainage pat- terns should be established to divert and remove water from the site to appropriate outlets. Care should be taken by the contractor during final grading to preserve any berms, drainage terraces, interceptor swales or other drainage devices of a permanent nature on or adjacent to the property. Drainage patterns established at the time of final grading should be maintained for the life of the project. The property owner and the mainte- nance personnel should be made aware that altering drainage patterns might be detrimental to foundation performance. Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc 16 8.2. Seismic Design Parameters Design of the proposed improvements should be performed in accordance with the require- ments of governing jurisdictions and applicable building codes. Table 1 presents the seismic design parameters for the site in accordance with the CBC (2013) guidelines and adjusted MCER spectral response acceleration parameters (USGS, 2013). Table 1 – 2013 California Building Code Seismic Design Criteria Site Coefficients and Spectral Response Acceleration Parameters Values Site Class D Site Coefficient, Fa 1.081 Site Coefficient, Fv 1.595 Mapped Short Period Spectral Acceleration at 0.2-second Period, SS 1.047g Mapped One-Second Period Spectral Acceleration at 1.0-second Period, S1 0.405g Short Period Spectral Acceleration at 0.2-second Period Adjusted For Site Class, SMS 1.132g One-Second Period Spectral Acceleration at 1.0-second Period Adjusted For Site Class, SM1 0.647g Design Short Period Spectral Acceleration at 0.2-second Period, SDS 0.755g Design One-Second Period Spectral Acceleration at 1.0-second Period, SD1 0.431g 8.3. Foundations We anticipate that the new emergency storage basin, and trailer mounted bypass pump will be founded on a mat foundation bearing on crushed rock/lean concrete base layer underlain by competent alluvium or recompacted soils, prepared in accordance with Section 8.1.6. Foundations should be designed in accordance with structural considerations and the follow- ing recommendations. In addition, requirements of the appropriate governing jurisdictions and applicable building codes should be considered in the design of the structures. 8.3.1. Mat Foundations An allowable bearing pressure of 1,000 pounds per square foot (psf) may be assumed for mat foundations bearing on crushed rock/lean concrete base layer underlain by competent alluvium or engineered fill, in accordance with Section 8.1.6. This allowable bearing ca- pacity may be increased by one-third when considering loads of a short duration such as wind or seismic forces. Thickness and reinforcement of the mat foundation should be in accordance with the recommendations of the project structural engineer. Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc 17 Mat foundations typically experience some deflection due to loads placed on the mat and the reaction of the soils underlying the mat. A design coefficient of subgrade reac- tion, Kv1, of 125 pounds per cubic inch may be used for evaluating such deflections at the subject sites. This value is based on a unit square-foot area and should be adjusted for the planned mat size. The coefficient of subgrade reaction Kb for a mat of specific width may be evaluated using the following equation: Kb = Kv1[(b+1)/2b]2 where b is the width of the foundation in feet. 8.3.2. Lateral Resistance For resistance of footings to lateral loads, we recommend an allowable passive pressure that can be evaluated in accordance with the following equation: Pp = 63D + 800psf Where, D is the footing embedment in feet The above value assumes that the ground is horizontal for a distance of 10 feet, or three times the height generating the passive pressure, whichever is greater. We recommend that the upper 1 foot of soil not protected by pavement or a concrete slab be neglected when calculating passive resistance. For frictional resistance to lateral loads, we recommend a coefficient of friction of 0.20 be used between soil and concrete. The allowable lateral resistance can be taken as the sum of the frictional resistance and passive resistance provided the passive re- sistance does not exceed one-half of the total allowable resistance. The passive resistance values may be increased by one-third when considering loads of short dura- tion such as wind or seismic forces. Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc 18 8.3.3. Static Settlement We estimate that the proposed structures, designed and constructed as recommended herein, will undergo total settlement on the order of 1 inch. Differential settlement on the order of ½ inch over a horizontal span of 30 feet should be expected. 8.4. Underground Structures Underground structures may be designed for lateral pressures represented by the pressure di- agram on Figure 8. For preliminary design purposes, we recommend that the groundwater level be assumed at an elevation of 96 MSL for evaluation of lateral pressures and calculat- ing the factor of safety against uplift. It is recommended that the exterior of underground walls, and horizontal and vertical construction joints be waterproofed, as indicated by the project civil engineer and/or architect. For pipe wall penetrations into the lift station, vaults, and other structures, standard “water-tight” penetration design should be utilized. To reduce the potential for relative pipe to wall differential settlement, which could cause pipe shear- ing, we recommend that a pipe joint be located close to the exterior of the wall. The type of joint should be such that minor relative movement can be accommodated without distress. 8.5. Uplift and Special Design Considerations We recommend that the underground structures be designed to resist hydrostatic uplift in ac- cordance with Figure 9. Alternative design measures for resisting the anticipated uplift pressure could include installation of vertical anchors, increasing mass by constructing a thicker concrete mat foundation, or extending the foundation a selected distance outside the exterior walls of the lift station/vaults (flanges). The resistance to uplift may then be taken as the sum of the weight of the structure and the weight of the soil wedge within the zone of in- fluence of the flanges shown on Figure 9. Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc 19 8.6. Concrete Flatwork Exterior concrete flatwork should be 4 inches in thickness and should be reinforced with No. 3 reinforcing bars placed at 24 inches on-center both ways. No vapor retarder is needed for exterior flatwork. To reduce the potential manifestation of distress to exterior concrete flatwork due to movement of the underlying soil, we recommend that such flatwork be in- stalled with crack-control joints at appropriate spacing as designed by the structural engineer. The subgrade soils should be scarified to a depth of 8 inches, moisture conditioned to generally above the laboratory optimum moisture content, and compacted to 90 percent of its modified Proctor density as evaluated by ASTM D 1557. Positive drainage should be es- tablished and maintained adjacent to flatwork. 8.7. Pavements For preliminary design purposes, we have assumed traffic index (TI) values of 5, 6, and 7 for our initial evaluation of pavement structural sections at the site. If traffic loads are different from those assumed herein, the pavement design should be re-evaluated. Actual pavement recom- mendations should be based on R-value tests performed on bulk samples of the soils exposed at the finished subgrade elevations once grading operations have been performed. Based on the results of our previous laboratory testing and experience with the on-site soils, we have used a design R-value of 9 for the preliminary design of flexible pavements at the project site. As noted above, actual pavement recommendations should be based on R-value tests performed on bulk samples of the soils exposed at the finished subgrade elevations following grading opera- tions. We recommend that the geotechnical consultant re-evaluate the pavement design at the time of construction. The recommended preliminary pavement sections are as follows: Table 2 – Recommended Preliminary Flexible Pavement Sections Traffic Index Design R-Value Asphalt Concrete (in) Class 2 Aggregate Base (in) 5 9 3.0 9.0 6 9 3.0 13.0 7 9 4.0 14.5 Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc 20 We recommend that the upper 12 inches of the subgrade, and aggregate base materials be compacted to a relative compaction of 95 percent relative density as evaluated by the current version of ASTM D 1557. If traffic loads are different from those assumed, the pavement design should be re-evaluated. Where rigid pavement sections are proposed, we recommend a 6-inch thickness of Portland cement concrete underlain by 4 inches of compacted aggregate base. We recommend that the Portland cement concrete have a 600 pounds per square inch (psi) flexural strength and that it be reinforced with No. 3 bars that are placed 18 inches on center (both ways). The rigid pavement and aggregate base should be placed on compacted subgrade that is prepared in accordance with the recommendations presented above. 8.8. Corrosivity Laboratory testing was performed on a representative sample of the on-site earth materials to evaluate pH and electrical resistivity, as well as chloride and sulfate contents. The pH and electrical resistivity tests were performed in accordance with California Test (CT) 643 and the sulfate and chloride content tests were performed in accordance with CT 417 and CT 422, respectively. These laboratory test results are presented in Appendix B. Corrosivity testing was performed on a sample of the upper soils obtained from our exploratory boring B-1. The results of the corrosivity testing indicated an electrical resistivity of 450 ohm- cm, soil pH of 7.8, a chloride content of 210 parts per million (ppm), and a soluble sulfate content of 0.094 percent (i.e., 940 ppm). According to Caltrans criteria (2012) corrosive soils are defined as soils with electrical resistivities less than 1,000 ohm-cm, more than 500 ppm chlorides, more than 0.20 percent sulfates, or a pH less than 5.5. Based on the Caltrans cor- rosion criteria (2012), the tested sample of the on-site soils would be classified as corrosive. Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc 21 8.9. Concrete Concrete in contact with soil or water that contains high concentrations of soluble sulfates can be subject to chemical deterioration. Laboratory testing indicated a sulfate content of 0.094 percent (i.e., 940 ppm) for the tested sample. Based on the American Concrete Institute (ACI) criteria (2011), the potential for sulfate attack is negligible for water-soluble sulfate contents in soils rang- ing from about 0.0 to 0.10 percent by weight (0 to 1,000 ppm). However, due to the potential variability of site soils, and the presence of groundwater, consideration should be given to using Type V or Type II/V cement and concrete with a water-cement ratio no higher than 0.45 by weight for normal weight aggregate concrete and a 28-day compressive strength of 4,500 pounds per square inch (psi) or more for the project. We further recommend that concrete cover over reinforc- ing steel for slabs-on-grade and foundations be in accordance with CBC 1907.7. The structural engineer should be consulted for additional concrete specifications. 9. PLAN REVIEW AND CONSTRUCTION OBSERVATION The conclusions and recommendations presented in this report are based on analysis of observed conditions in widely spaced exploratory excavations. If conditions are found to vary from those described in this report, Ninyo & Moore should be notified, and additional recommendations will be provided upon request. Ninyo & Moore should review the final project drawings and specifica- tions prior to the commencement of construction. Ninyo & Moore should perform the needed observation and testing services during construction operations. The recommendations provided in this report are based on the assumption that Ninyo & Moore will provide geotechnical observation and testing services during construction. In the event that it is decided not to utilize the services of Ninyo & Moore during construction, we request that the selected consultant provide the client with a letter (with a copy to Ninyo & Moore) indicating that they fully understand Ninyo & Moore’s recommendations, and that they are in full agree- ment with the design parameters and recommendations contained in this report. Construction of proposed improvements should be performed by qualified subcontractors utilizing appropriate techniques and construction materials. Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc 22 10. LIMITATIONS The field evaluation, laboratory testing, and geotechnical analyses presented in this geotechnical report have been conducted in general accordance with current practice and the standard of care exercised by geotechnical consultants performing similar tasks in the project area. No warranty, expressed or im- plied, is made regarding the conclusions, recommendations, and opinions presented in this report. There is no evaluation detailed enough to reveal every subsurface condition. Variations may exist and conditions not observed or described in this report may be encountered during construction. Uncertain- ties relative to subsurface conditions can be reduced through additional subsurface exploration. Additional subsurface evaluation will be performed upon request. Please also note that our evaluation was limited to assessment of the geotechnical aspects of the project, and did not include evaluation of structural issues, environmental concerns, or the presence of hazardous materials. This document is intended to be used only in its entirety. No portion of the document, by itself, is designed to completely represent any aspect of the project described herein. Ninyo & Moore should be contacted if the reader requires additional information or has questions regarding the content, interpretations presented, or completeness of this document. This report is intended for design purposes only. It does not provide sufficient data to prepare an accurate bid by contractors. It is suggested that the bidders and their geotechnical consultant per- form an independent evaluation of the subsurface conditions in the project areas. The independent evaluations may include, but not be limited to, review of other geotechnical reports prepared for the adjacent areas, site reconnaissance, and additional exploration and laboratory testing. Our conclusions, recommendations, and opinions are based on an analysis of the observed site conditions. If geotechnical conditions different from those described in this report are encountered, our office should be notified and additional recommendations, if warranted, will be provided upon request. It should be understood that the conditions of a site could change with time as a result of natural processes or the activities of man at the subject site or nearby sites. In addition, changes to the applicable laws, regulations, codes, and standards of practice may occur due to government ac- tion or the broadening of knowledge. The findings of this report may, therefore, be invalidated over time, in part or in whole, by changes over which Ninyo & Moore has no control. Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc 23 This report is intended exclusively for use by the client. Any use or reuse of the findings, conclu- sions, and/or recommendations of this report by parties other than the client is undertaken at said parties’ sole risk. Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc 24 11. REFERENCES American Concrete Institute, 2011, ACI 318 Building Code Requirements for Structural Con- crete (ACI 318) and Commentary (ACI 318R). Bowles, J.E., 1996, Foundation Analysis and Design, Fifth Edition, The McGraw-Hill Compa- nies, Inc. Bray, J.D., and Sancio, R.B., 2006, Assessment of the Liquefaction Susceptibility of Fine- Grained Soils: American Society of Civil Engineers, Journal of the Geotechnical and Ge- oenvironmental Engineering, v. 132, n. 9, p. 1165-1177. California Building Standards Commission (CBSC), 2013, California Building Code (CBC), Ti- tle 24, Part 2, Volumes 1 and 2: dated June. California Department of Transportation (Caltrans), 2012, Corrosion Guidelines, Version 2.0, Division of Engineering Services, Materials Engineering and Testing Services, Corrosion and Structural Concrete Field Investigation Branch: dated November. Carlsbad, City of, Improvement Plans for Poinsettia Sewage Lift Station, 50 percent Progress Set, Sheets C-1 and M-2, undated. California Geological Survey (CGS), 2008, Guidelines for Evaluating and Mitigating Seismic Haz- ards in California, CGS Special Publication 117A. Cao, T., Bryant, W. A., Rowshandel, B., Branum, D., and Willis, C. J., 2003, The Revised 2002 Cali- fornia Probabilistic Seismic Hazards Maps: California Geological Survey: dated June. GEOCON, Inc., 1993, Geotechnical Investigation, North La Costa Pump Station, Carlsbad, Cali- fornia, Project No. 04787-12-06: dated April 5. Google, Inc., 2014, www.googleearth.com. Harden, D.R., 2004, California Geology – 2nd ed.: Prentice Hall, Inc. Hartley, J.D. and Duncan, J.M., 1987, “E” and Its Variation with Depth, ASCE Journal of Trans- portation, Volume 113, No. 5, 538-553. Jennings, C.W. and Bryant, W. A., 2010, Fault Activity Map of California: California Geological Survey, Geologic Data Map No. 6. Kennedy, M.P., and Tan, S. S., 2008 Geologic Map of the Oceanside 30’ X 60’ Quadrangle, Cali- fornia Regional Geologic Map Series, Scale 1:100,000. Ninyo & Moore, 2006, Geotechnical Evaluation, Alga Norte Community Park, Carlsbad, Cali- fornia, Project No. 104600002: dated June 14. Ninyo & Moore, In-house proprietary information. Norris, R.M., and Webb, R.W., 1990, Geology of California: John Wiley & Sons, pp. 541. Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc 25 Peterson, M.D., Bryant, W.A., Cramer, C.H., Cao, T., Reichle, M.S., 1996, Probabilistic Seismic Hazard Assessment for the State of California: California Department of Conservation Division of Mines and Geology Open File Report 96-08, and United States Department of the Interior United States Geological Survey Open File Report 96-706. Public Works Standards, Inc., 2012, “Greenbook,” Standard Specifications for Public Works Construction. San Diego, County of, 1975 Ortho-topographic Survey, Sheet 346-1689, scale 1:2,400. Tan, S. S., 1995, Landslide Hazards in the Northern Part of the San Diego Metropolitan Area, San Diego County, California, California Division of Mines and Geology Open-File Report 95- 04, scale 1:24,000. United States Department of the Interior, Bureau of Reclamation, 1989, Engineering Geology Field Manual. United States Geological Survey, 2015, Encinitas Quadrangle, California, San Diego County, 7.5-Minute Series (Topographic): Scale 1:24,000. United States Geological Survey, 2008 National Seismic Hazard Maps - Fault Parameters Database, World Wide Web, http://Geohazards.Usgs.Gov/Cfusion/Hazfaults_Search/Hf_Search_Main.Cfm: accessed May, 2014. United States Geological Survey, 2013, Seismic Design Maps Application, http://geohazards.usgs.gov/designmaps/us/application.php. AERIAL PHOTOGRAPHS Source Date Flight Numbers Scale USDA 4-11-1953 AXN-8M 19 and 20 1:24,000 8 5 15 MAP INDEX San Dieg oCounty 0 1,500 3,000 SCALE IN FEET NOTE: DIRECTIONS, DIMENSIONS AND LOCATIONS ARE APPROXIMATE. SITE LOCATION FIGURE 1PROJECT NO.DATE SITE SOURCE: ESRI WORLD TOPO, 2015 1_107544009_SL.mxd 6/9/2015 JDLPOINSETTIA LIFT STATION CARLSBAD, CALIFORNIA1075440096/15 B-2 TD=35.5 B-1 TD=46.5 2_107544009_BL.mxd 5/11/2015 JDLNOTE: DIRECTIONS, DIMENSIONS AND LOCATIONS ARE APPROXIMATE. POINSETTIA LIFT STATION CARLSBAD, CALIFORNIA BORING LOCATIONS FIGURE 2PROJECT NO.DATE 107544009 6/15 GEODE LANE 0 60 120 SCALE IN FEET SOURCE: AERIAL IMAGERY - ©2015 PICTOMETRY INTERNATIONAL CORP. LEGEND BORING TD=TOTAL DEPTH IN FEET B-2 TD=35.5 P O I N S E T T I A L A N E 0 2,000 4,000 SCALE IN FEET NOTE: DIRECTIONS, DIMENSIONS AND LOCATIONS ARE APPROXIMATE. GEOLOGY FIGURE 3PROJECT NO.DATE SITE 3_107544009_G.mxd 6/9/2015 JDLPOINSETTIA LIFT STATION CARLSBAD, CALIFORNIA1075440096/15 MzuLEGEND REFERENCE: KENNEDY, M.P. AND TAN, S.S., CALIFORNIA GEOLOGICAL SURVEY, 2008, GEOLOGIC MAP OF THE SAN DIEGO 30' X 60' QUADRANGLE, CALIFORNIA M E X I C OUSAPacific O c e a n NEVADA CALIFORNIA SAN JACINTO ELSINORE IM P E RIA L WHITTIER NEW PORT-INGLEWOOD C O R O N A D O B A N K S A N DIE G O T R O U G H SAN CLE M ENTE S A N TA C RUZ-SANTACATALINARIDGE P A L O S VERDES OFFSHORE ZONE OF DEFORMATIONGARLOCKCLEARWATERS A N GABRIEL SIERRAMADRE BANNING MISSION CREEK B LA C K W AT ERHARPER LOCKHART LEN W O O D CAMPROCK CALIC O LUDL O W PIS GAHBULLION M O U N T AIN JO HNS O N VALLEY E MERSON P IN T O M O U NTAINMANIX MIRAGEVALLEY NORTHHELENDALE FRONTAL CHIN O S A N J O S ECUCAMO N G A MALIBU COAST SA N T A MONICA SANCAYETANO SANTASUSANASANTAROSA N O R T H R ID G E C H AR N OC K S A W P ITCAN Y O N SUPERSTITION HILLS R O S E C ANYONPINEMOUNTAIN W HITEW OLFSAN ANDREAS FAULT ZONEPLEITOWHEELER POSOCREEK San Bernardino County Kern County Riverside County San Diego County Imperial County Los Angeles County Inyo CountyTulare County Ventura County Orange County CALI FORN IA LEGEND HOLOCENE ACTIVE CALIFORNIA FAULT ACTIVITY HISTORICALLY ACTIVE LATE QUATERNARY (POTENTIALLY ACTIVE) STATE/COUNTY BOUNDARY QUATERNARY (POTENTIALLY ACTIVE) SITE NOTE: DIRECTIONS, DIMENSIONS AND LOCATIONS ARE APPROXIMATE. FAULT LOCATIONS FIGURE 4PROJECT NO.DATE 6/15 0 30 60 SCALE IN MILES SOURCE: U.S. GEOLOGICAL SURVEY AND CALIFORNIA GEOLOGICAL SURVEY, 2006, QUATERNARY FAULT AND FOLD DATABASE FOR THE UNITED STATES.4_107544009_F.mxd 6/9/2015 10:51:06 AM JDLPOINSETTIA LIFT STATION CARLSBAD, CALIFORNIA107544009 Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc APPENDIX A BORING LOGS Field Procedure for the Collection of Disturbed Samples Disturbed soil samples were obtained in the field using the following methods. Bulk Samples Bulk samples of representative earth materials were obtained from the cuttings of the explora- tory borings. The samples were bagged and transported to the laboratory for testing. The Standard Penetration Test (SPT) Sampler Disturbed drive samples of earth materials were obtained by means of a Standard Penetra- tion Test sampler. The sampler is composed of a split barrel with an external diameter of 2 inches and an unlined internal diameter of 1-3/8 inches. The sampler was driven into the ground 12 to 18 inches with a 140-pound hammer falling freely from a height of 30 inches in general accordance with ASTM D 1586. The blow counts were recorded for every 6 inches of penetration; the blow counts reported on the logs are those for the last 12 inches of penetration. Soil samples were observed and removed from the sampler, bagged, sealed and transported to the laboratory for testing. Field Procedure for the Collection of Relatively Undisturbed Samples Relatively undisturbed soil samples were obtained in the field using a modified split-barrel drive sampler. The sampler, with an external diameter of 3.0 inches, was lined with 1-inch long, thin brass rings with inside diameters of approximately 2.4 inches. The sample barrel was driven into the ground with the weight of a 140-pound hammer, in general accordance with ASTM D 3550. The driving weight was permitted to fall freely. The approximate length of the fall, the weight of the hammer, and the number of blows per foot of driving are presented on the boring logs as an index to the relative resistance of the materials sampled. The samples were removed from the sam- ple barrel in the brass rings, sealed, and transported to the laboratory for testing. 0 5 10 15 20 XX/XX SM CL Bulk sample. Modified split-barrel drive sampler. 2-inch inner diameter split-barrel drive sampler. No recovery with modified split-barrel drive sampler, or 2-inch inner diameter split-barrel drive sampler. Sample retained by others. Standard Penetration Test (SPT). No recovery with a SPT. Shelby tube sample. Distance pushed in inches/length of sample recovered in inches. No recovery with Shelby tube sampler. Continuous Push Sample. Seepage. Groundwater encountered during drilling. Groundwater measured after drilling. MAJOR MATERIAL TYPE (SOIL):Solid line denotes unit change. Dashed line denotes material change. Attitudes: Strike/Dip b: Bedding c: Contact j: Joint f: Fracture F: Fault cs: Clay Seam s: Shear bss: Basal Slide Surface sf: Shear Fracture sz: Shear Zone sbs: Shear Bedding Surface The total depth line is a solid line that is drawn at the bottom of the boring. BORING LOG Explanation of Boring Log Symbols PROJECT NO. DATE FIGUREDEPTH (feet)BulkSAMPLESDrivenBLOWS/FOOTMOISTURE (%)DRY DENSITY (PCF)SYMBOLCLASSIFICATIONU.S.C.S.BORING LOG EXPLANATION SHEET SOIL CLASSIFICATION CHART PER ASTM D 2488 PRIMARY DIVISIONS SECONDARY DIVISIONS GROUP SYMBOL GROUP NAME COARSE- GRAINED SOILS more than 50% retained on No. 200 sieve GRAVEL more than 50% of coarse fraction retained on No. 4 sieve CLEAN GRAVELless than 5% fines GW well-graded GRAVEL GP poorly graded GRAVEL GRAVEL with DUAL CLASSIFICATIONS 5% to 12% fines GW-GM well-graded GRAVEL with silt GP-GM poorly graded GRAVEL with silt GW-GC well-graded GRAVEL with clay GP-GC poorly graded GRAVEL with clay GRAVEL with FINES more than 12% fines GM silty GRAVEL GC clayey GRAVEL GC-GM silty, clayey GRAVEL SAND 50% or more of coarse fraction passes No. 4 sieve CLEAN SAND less than 5% fines SW well-graded SAND SP poorly graded SAND SAND with DUAL CLASSIFICATIONS 5% to 12% fines SW-SM well-graded SAND with silt SP-SM poorly graded SAND with silt SW-SC well-graded SAND with clay SP-SC poorly graded SAND with clay SAND with FINES more than 12% fines SM silty SAND SC clayey SAND SC-SM silty, clayey SAND FINE- GRAINED SOILS 50% or more passes No. 200 sieve SILT and CLAY liquid limit less than 50% INORGANIC CL lean CLAY ML SILT CL-ML silty CLAY ORGANIC OL (PI > 4)organic CLAY OL (PI < 4)organic SILT SILT and CLAY liquid limit 50% or more INORGANIC CH fat CLAY MH elastic SILT ORGANIC OH (plots on or above “A”-line)organic CLAY OH (plots below “A”-line)organic SILT Highly Organic Soils PT Peat USCS METHOD OF SOIL CLASSIFICATION Explanation of USCS Method of Soil Classification PROJECT NO.DATE FIGURE APPARENT DENSITY - COARSE-GRAINED SOIL APPARENT DENSITY SPOOLING CABLE OR CATHEAD AUTOMATIC TRIP HAMMER SPT (blows/foot) MODIFIED SPLIT BARREL (blows/foot) SPT (blows/foot) MODIFIED SPLIT BARREL (blows/foot) Very Loose < 4 < 8 < 3 < 5 Loose 5 - 10 9 - 21 4 - 7 6 - 14 Medium Dense 11 - 30 22 - 63 8 - 20 15 - 42 Dense 31 - 50 64 - 105 21 - 33 43 - 70 Very Dense > 50 > 105 > 33 > 70 CONSISTENCY - FINE-GRAINED SOIL CONSIS-TENCY SPOOLING CABLE OR CATHEAD AUTOMATIC TRIP HAMMER SPT (blows/foot) MODIFIED SPLIT BARREL (blows/foot) SPT (blows/foot) MODIFIED SPLIT BARREL (blows/foot) Very Soft < 2 < 3 < 1 < 2 Soft 2 - 4 3 - 5 1 - 3 2 - 3 Firm 5 - 8 6 - 10 4 - 5 4 - 6 Stiff 9 - 15 11 - 20 6 - 10 7 - 13 Very Stiff 16 - 30 21 - 39 11 - 20 14 - 26 Hard > 30 > 39 > 20 > 26 LIQUID LIMIT (LL), %PLASTICITY INDEX (PI), %0 10 107 4 20 30 40 50 60 70 0 20 30 40 50 60 70 80 90 100 MH or OH ML or OLCL - ML PLASTICITY CHART GRAIN SIZE DESCRIPTION SIEVE SIZE GRAIN SIZE APPROXIMATE SIZE Boulders > 12”> 12”Larger than basketball-sized Cobbles 3 - 12”3 - 12”Fist-sized to basketball-sized Gravel Coarse 3/4 - 3”3/4 - 3”Thumb-sized to fist-sized Fine #4 - 3/4”0.19 - 0.75”Pea-sized to thumb-sized Sand Coarse #10 - #4 0.079 - 0.19”Rock-salt-sized to pea-sized Medium #40 - #10 0.017 - 0.079”Sugar-sized to rock-salt-sized Fine #200 - #40 0.0029 - 0.017” Flour-sized to sugar-sized Fines Passing #200 < 0.0029”Flour-sized and smaller CH or OH CL or OL 0 10 20 30 40 21 25 32 29 27 57 95 22.5 21.8 19.2 21.9 25.1 14.2 17.8 100.8 102.9 105.6 101.9 98.1 118.1 111.6 GM CL CL CH ASPHALT CONCRETE:Approximately 4 inches thick. AGGREGATE BASE:Brown, moist, dense, silty GRAVEL with sand; approximately 26 inches thick. FILL: Gray, moist, very stiff, silty CLAY. ALLUVIUM:Brown, moist, very stiff, silty CLAY. Gray. Light brown to light gray; hard; sand and scattered gravel; carbon staining. Wet. Light gray to greenish gray, wet, hard, fat CLAY. SANTIAGO FORMATION:Light brown, wet, weakly cemented, silty fine-grained SANDSTONE. Light brown, wet, moderately indurated, fine sandy SILTSTONE. BORING LOG POINSETTIA LIFT STATION CARLSBAD, CALIFORNIA PROJECT NO. 107544009 DATE 6/15 FIGURE A-1DEPTH (feet)BulkSAMPLESDrivenBLOWS/FOOTMOISTURE (%)DRY DENSITY (PCF)SYMBOLCLASSIFICATIONU.S.C.S.DESCRIPTION/INTERPRETATION DATE DRILLED 5/06/15 BORING NO.B-1 GROUND ELEVATION 110' (MSL)SHEET 1 OF METHOD OF DRILLING 8" Diameter Hollow Stem Auger (CME-75) (Baja) DRIVE WEIGHT 140 lbs. (Auto-Trip)DROP 30" SAMPLED BY BTM LOGGED BY BTM REVIEWED BY GTF 2 40 50 60 70 80 88/11" 50/4" 19.0 29.1 107.2 101.9 SANTIAGO FORMATION: (Continued)Light gray, wet, moderately indurated, fine sandy SILTSTONE. @ Approximately 40': Harder drilling. Total Depth = 46.5 feet. Groundwater encountered at approximately 35 feet during drilling and approximately 22 feet after drilling. Backfilled with approximately 16 cubic feet of bentonite grout and black-dyed concrete cap shortly after drilling on 5/06/15. Note: Groundwater may rise to a level higher than that measured in borehole due to seasonal variations in precipitation and several other factors as discussed in the report. The ground elevation shown above is an estimation only. It is based on our interpretations of published maps and other documents reviewed for the purposes of this evaluation. It is not sufficiently accurate for preparing construction bids and design documents. BORING LOG POINSETTIA LIFT STATION CARLSBAD, CALIFORNIA PROJECT NO. 107544009 DATE 6/15 FIGURE A-2DEPTH (feet)BulkSAMPLESDrivenBLOWS/FOOTMOISTURE (%)DRY DENSITY (PCF)SYMBOLCLASSIFICATIONU.S.C.S.DESCRIPTION/INTERPRETATION DATE DRILLED 5/06/15 BORING NO.B-1 GROUND ELEVATION 110' (MSL)SHEET 2 OF METHOD OF DRILLING 8" Diameter Hollow Stem Auger (CME-75) (Baja) DRIVE WEIGHT 140 lbs. (Auto-Trip)DROP 30" SAMPLED BY BTM LOGGED BY BTM REVIEWED BY GTF 2 0 10 20 30 40 23 29 30 30 26 50/5" 62 19.4 19.1 20.1 21.9 21.8 20.4 20.6 108.0 107.4 106.0 105.0 101.8 105.9 GM CL CL ASPHALT CONCRETE:Approximately 4 inches thick. AGGREGATE BASE:Brown, moist, dense, silty GRAVEL with sand; approximately 26 inches thick. FILL: Gray, moist, very stiff, silty CLAY. ALLUVIUM:Gray to brown, moist, hard, sandy CLAY. Wet. Greenish gray to light brown. Gray; very stiff. SANTIAGO FORMATION:Greenish gray to light brown, wet, moderately cemented, silty fine-grained SANDSTONE.@ 30': Very hard drilling. Greenish gray to light brown, wet, moderately indurated, fine sandy SILTSTONE. Total Depth = 35.5 feet Groundwater encountered at approximately 12 feet after drilling. Backfilled with approximately 12 cubic feet of bentonite grout and black-dyed concrete cap shortly after drilling on 5/06/15. BORING LOG POINSETTIA LIFT STATION CARLSBAD, CALIFORNIA PROJECT NO. 107544009 DATE 6/15 FIGURE A-3DEPTH (feet)BulkSAMPLESDrivenBLOWS/FOOTMOISTURE (%)DRY DENSITY (PCF)SYMBOLCLASSIFICATIONU.S.C.S.DESCRIPTION/INTERPRETATION DATE DRILLED 5/06/15 BORING NO.B-2 GROUND ELEVATION 110' (MSL)SHEET 1 OF METHOD OF DRILLING 8" Diameter Hollow Stem Auger (CME-75) (Baja) DRIVE WEIGHT 140 lbs. (Auto-Trip)DROP 30" SAMPLED BY BTM LOGGED BY BTM REVIEWED BY GTF 2 40 50 60 70 80 Note: Groundwater may rise to a level higher than that measured in borehole due to seasonal variations in precipitation and several other factors as discussed in the report The ground elevation shown above is an estimation only. It is based on our interpretations of published maps and other documents reviewed for the purposes of this evaluation. It is not sufficiently accurate for preparing construction bids and design documents. BORING LOG POINSETTIA LIFT STATION CARLSBAD, CALIFORNIA PROJECT NO. 107544009 DATE 6/15 FIGURE A-4DEPTH (feet)BulkSAMPLESDrivenBLOWS/FOOTMOISTURE (%)DRY DENSITY (PCF)SYMBOLCLASSIFICATIONU.S.C.S.DESCRIPTION/INTERPRETATION DATE DRILLED 5/06/15 BORING NO.B-2 GROUND ELEVATION 110' (MSL)SHEET 2 OF METHOD OF DRILLING 8" Diameter Hollow Stem Auger (CME-75) (Baja) DRIVE WEIGHT 140 lbs. (Auto-Trip)DROP 30" SAMPLED BY BTM LOGGED BY BTM REVIEWED BY GTF 2 Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc APPENDIX B LABORATORY TESTING Classification Soils were visually and texturally classified in accordance with the Unified Soil Classification System (USCS) in general accordance with ASTM D 2488. Soil classifications are indicated on the logs of the exploratory borings in Appendix A. In-Place Moisture and Density Tests The moisture content and dry density of relatively undisturbed samples obtained from the ex- ploratory borings were evaluated in general accordance with ASTM D 2937. The test results are presented on the logs of the exploratory borings in Appendix A. Gradation Analysis Gradation analysis tests were performed on selected representative soil samples in general accord- ance with ASTM D 422. The grain-size distribution curves are shown on Figures B-1 through B-4. The test results were utilized in evaluating the soil classifications in accordance with the USCS. Atterberg Limits Tests were performed on selected representative fine-grained soil samples to evaluate the liquid limit, plastic limit, and plasticity index in general accordance with ASTM D 4318. These test re- sults were utilized to evaluate the soil classification in accordance with the Unified Soil Classification System (USCS). The test results and classifications are shown on Figure B-5. Consolidation Tests Consolidation tests were performed on a selected relatively undisturbed soil sample in general accordance with ASTM D 2435. The sample was inundated during testing to represent adverse field conditions. The percent of consolidation for each load cycle was recorded as a ratio of the amount of vertical compression to the original height of the sample. The results of the test are summarized on Figure B-6. Direct Shear Tests One direct shear test was performed on a sample in general accordance with ASTM D 3080 to evalu- ate the shear strength characteristics of the selected material. The sample was inundated during shearing to represent adverse field conditions. The test results are shown on Figure B-7. R-Value The resistance value, or R-value, for site soils was evaluated in general accordance with Califor- nia Test (CT) 301. Samples were prepared and evaluated for exudation pressure and expansion pressure. The equilibrium R-value is reported as the lesser or more conservative of the two calcu- lated results. The test results are shown on Figure B-8. Poinsettia Lift Station June 10, 2015 Carlsbad, California Project No. 107544009 107544009 R.doc 2 Soil Corrosivity Tests Soil pH, and electrical resistivity tests were performed on a representative sample in general ac- cordance with CT 643. The chloride content of the selected sample was evaluated in general accordance with CT 422. The sulfate content of the selected sample was evaluated in general ac- cordance with CT 417. The test results are presented on Figure B-9. Coarse Fine Coarse Medium SILT CLAY 3" 2"¾"½" ⅜"4 8 3050 PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 422 107544009 6/15 B-1 POINSETTIA LIFT STATION CARLSBAD, CALIFORNIA Fine Sample Location 100 D10 16 200 GRAVEL SAND FINES Symbol Plasticity Index Plastic Limit Liquid Limit 1½" 1" Depth (ft)D30 Cc B-1 10.0-11.5 47 20 27 Cu -- USCS -- D60 CL-- -- -- 74 Passing No. 200 (%) 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0 100.0 0.00010.0010.010.1110100PERCENT FINER BY WEIGHTGRAIN SIZE IN MILLIMETERS U.S. STANDARD SIEVE NUMBERS HYDROMETER GRADATION TEST RESULTS PROJECT NO. DATE FIGURE 107544009 SIEVE B-1 @ 10.0-11.5.xls Coarse Fine Coarse Medium SILT CLAY 3" 2"¾"½" ⅜"4 8 3050 PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 422 -- D60 CH-- -- -- 80 Passing No. 200 (%) Cc Fine Sample Location 100 D10 16 B-1 25.0-26.5 56 24 32 GRAVEL SAND FINES Symbol Plasticity Index Plastic Limit Liquid Limit 1½" 1" Depth (ft)D30 200 107544009 6/15 B-2 POINSETTIA LIFT STATION CARLSBAD, CALIFORNIA Cu -- USCS 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0 100.0 0.00010.0010.010.1110100PERCENT FINER BY WEIGHTGRAIN SIZE IN MILLIMETERS U.S. STANDARD SIEVE NUMBERS HYDROMETER GRADATION TEST RESULTS PROJECT NO. DATE FIGURE 107544009 SIEVE B-1 @ 25.0-26.5.xls Coarse Fine Coarse Medium SILT CLAY 3" 2"¾"½" ⅜"4 8 3050 PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 422 107544009 6/15 B-3 POINSETTIA LIFT STATION CALSBAD, CALIFORNIA Fine Sample Location 100 D10 16 200 GRAVEL SAND FINES Symbol Plasticity Index Plastic Limit Liquid Limit 1½" 1" Depth (ft)D30 Cc B-2 5.0-6.5 38 17 21 Cu -- USCS -- D60 CL-- -- -- 59 Passing No. 200 (%) 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0 100.0 0.00010.0010.010.1110100PERCENT FINER BY WEIGHTGRAIN SIZE IN MILLIMETERS U.S. STANDARD SIEVE NUMBERS HYDROMETER GRADATION TEST RESULTS PROJECT NO. DATE FIGURE 107544009 SIEVE B-2 @ 5.0-6.5.xls Coarse Fine Coarse Medium SILT CLAY 3" 2"¾"½" ⅜"4 8 3050 PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 422 107544009 6/15 B-4 POINSETTIA LIFT STATION CARLSBAD, CALIFORNIA Fine Sample Location 100 D10 16 200 GRAVEL SAND FINES Symbol Plasticity Index Plastic Limit Liquid Limit 1½" 1" Depth (ft)D30 Cc B-2 15.0-16.5 38 17 21 Cu -- USCS -- D60 CL-- -- -- 69 Passing No. 200 (%) 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0 100.0 0.00010.0010.010.1110100PERCENT FINER BY WEIGHTGRAIN SIZE IN MILLIMETERS U.S. STANDARD SIEVE NUMBERS HYDROMETER GRADATION TEST RESULTS PROJECT NO. DATE FIGURE 107544009 SIEVE B-2 @ 15.0-16.5.xls LOCATION NP - INDICATES NON-PLASTIC PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4318 POINSETTIA LIFT STATION CARLSBAD, CALIFORNIA CL 2117 17 CL CH 21 CL CH CL CL CL No. 40 Sieve) SYMBOL 10.0-11.5 2747 (FT) DEPTH 20B-1 CLASSIFICATION 32 15.0-16.5 5.0-6.5 56 38 38 25.0-26.5 24B-1 B-2 B-2 INDEX, PI LIQUID PLASTIC PLASTICITY LIMIT, LL 107544009 6/15 B-5 USCS USCS (Entire Sample)(Fraction Finer ThanLIMIT, PL CH or OH CL or OL MH or OH ML or OLCL - ML 0 10 20 30 40 50 60 0 102030405060708090100PLASTICITY INDEX, PI LIQUID LIMIT, LL ATTERBERG LIMITS TEST RESULTS PROJECT NO. DATE FIGURE 107544009 ATTERBERG Page 1.xls Seating Cycle Sample Location B-2 Loading Prior to Inundation Depth (ft.)25.0-26.5 Loading After Inundation Soil Type CL Rebound Cycle PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 2435 107544009 POINSETTIA LIFT STATION CARLSBAD, CALIFORNIA B-66/15 -4.0 -3.0 -2.0 -1.0 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 0.1 1.0 10.0 100.0 CONSOLIDATION IN PERCENT OF SAMPLE THICKNESS (%) EXPANSION (%)STRESS IN KIPS PER SQUARE FOOT CONSOLIDATION TEST RESULTS PROJECT NO. DATE FIGURE 107544009 CONSOLIDATION B-2 @ 25.0-26.5.xls X Description Symbol Sample Location 410 Depth (ft) Shear Strength 15.0-16.5CLAY B-1 Peak Cohesion, c (psf) Friction Angle, (degrees)Soil Type CL12 12 390 CL Ultimate15.0-16.5B-1 B-7 PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 3080 CLAY 107544009 6/15 POINSETTIA LIFT STATION CARLSBAD, CALIFORNIA 0 1000 2000 3000 4000 5000 0 1000 2000 3000 4000 5000SHEAR STRESS (PSF)NORMAL STRESS (PSF) DIRECT SHEAR TEST RESULTS PROJECT NO. DATE FIGURE 107544009 SHEAR B-1 @ 15.0-16.5.xls PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 2844/CT 301 SAMPLE LOCATION SAMPLE DEPTH (FT)SOIL TYPE R-VALUE 3.0-8.0B-2 9CLAY (CL) B-8 6/15107544009 POINSETTIA LIFT STATION CARLSBAD, CALIFORNIA R-VALUE TEST RESULTS PROJECT NO.DATE FIGURE 107544009 R-VALUE Page 1.xls 1 PERFORMED IN GENERAL ACCORDANCE WITH CALIFORNIA TEST METHOD 643 2 PERFORMED IN GENERAL ACCORDANCE WITH CALIFORNIA TEST METHOD 417 3 PERFORMED IN GENERAL ACCORDANCE WITH CALIFORNIA TEST METHOD 422 940 0.094 6/15 B-9POINSETTIA LIFT STATION CARLSBAD, CALIFORNIA B-1 3.0-8.0 7.8 CHLORIDE CONTENT 3 (ppm) pH 1SAMPLE DEPTH (FT) SAMPLE LOCATION (Ohm-cm) RESISTIVITY 1 SULFATE CONTENT 2 (%)(ppm) 210450 107544009 CORROSIVITY TEST RESULTS PROJECT NO. DATE FIGURE 107544009 CORROSIVITY Page 1.xls