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HomeMy WebLinkAboutSDP 2022-0003; FPC RESIDENTIAL - SB 330; ADDENDUM REPORT AND RESPONSE TO CITY GEOTECHNICAL COMMENTS; 2022-10-06 ADVANCED GEOTECHNICAL SOLUTIONS, INC. 485 Corporate Drive, Suite B Escondido, California 92029 Telephone: (619) 867-0487 Fax: (714) 409-3287 ADVANCED GEOTECHNICAL SOLUTIONS, INC. H.G. Fenton Company October 6, 2022 7577 Mission Valley Road P/W 2107-12 San Diego, California 92108 Report No. 2107-12-B-7R SDP 2022-0003/CDP2022-0023 (DEV2022-0048) Attention: Mr. Ryley Webb Subject: Addendum Report and Response to City Geotechnical Comments, Proposed Multi- Family Residential Development, 7200-7294 Ponto Drive, Carlsbad, California References: See Appendix Gentlepersons, Advanced Geotechnical Solutions, Inc., (AGS) has prepared this letter presenting our response to geotechnical related review comments by the City of Carlsbad related to our referenced geotechnical report dated March 16, 2022. The 2nd cycle review comments were presented in a letter dated September 1, 2022. The related review comments precede AGS’s response. A copy of the Review Sheet is appended. Comment 23.a: Please provide a statement addressing the potential impact of the proposed project on adjacent properties. AGS Response: The proposed project is not expected to destabilize nor induce settlement of adjacent properties provided the recommendations presented in AGS’s referenced report (2022b) are implemented in the project’s design and construction. Comment 23.b: On the "Exploration Location Map" (Plate 1) of the report, please clarify and show/label the location of the high-pressure gas line and associated 10'-wide easement that reportedly traverses the subject site. AGS Response: AGS has revised the plan to utilize the existing and proposed utility plan as a base and included it herein as Plate 1. The plan shows the locations of existing utilities, including the gas line and associated easement. Comment 23.c: Please discuss the geologic structure associated with the Old Paralic deposits and potential impact on the proposed development. AGS Response: The Old Paralic deposits are essentially flat lying paralic sediments deposited on wave- cut terraces that have been preserved due to regional uplift. The Old Paralic deposits typically consist of interfingered non-marine and near shore shallow marine deposits. AGS observed a distinct clay layer within the Old Paralic deposits in several test pits and borings. The top of this is clay layer was observed at elevations of around 36 to 37 feet, which may indicate that the Old Paralic deposits in the site vicinity are flat lying to shallowly dipping to the southeast. The proposed development is generally level, with October 6, 2022 Page 2 P/W 2107-12 Report No. 2107-12-B-7R ADVANCED GEOTECHNICAL SOLUTIONS, INC. maximum cuts and fills on the order of a few feet. Fill slopes up to 3 feet are proposed onsite. The geologic structure of the Old Paralic deposits is considered neutral in respect to the proposed development. Comment 23.d: Please discuss the estimated thickness of the Old Paralic deposits and depth of the geologic contact with the underlying Santiago formation bedrock unit beneath the subject property. AGS Response: AGS did not encounter the Santiago Formation in any of the test pits or borings drilled onsite. The maximum depths explored onsite extended to around 21.5 feet, which corresponds to an elevation of around 18 feet above mls. Boring B-1, drilled on the adjacent southerly parcel was advanced to a maximum depth of 26.5 feet and did not encounter the Santiago Formation. AGS has reviewed the geotechnical reports for the adjacent hotel property, completed by Geotechnics Incorporated (2009). Their investigation included the drilling of 2 borings within the footprint of the adjacent parking structure north of the project site. AGS has shown the approximate locations of these borings on Plate 1. The boring logs indicated that materials associated with the Santiago Formation were encountered at depths of around 17.5 to 18 feet, corresponding to an elevation of around 30 to 30.5 feet above msl. The thickness of the Old Paralic deposits is expected to be somewhat variable across the site and adjacent properties, but appears to be thinner north of the property (~17 to 18 feet when combined with overlying surficial fill deposits) and thicker towards the south (at least 26.5 feet based on Boring B-1). The deepest utility excavations are expected south of the property, where excavations of the storm drain may approach 22 feet in depth. The deepest utility excavations within the north half of the project include the sewer line, which will be on the order of 7 to 8 feet in depth. It is not anticipated that the Santiago Formation will be encountered during the construction of the development and its improvements. Comment 23.e: Please provide a discussion addressing the local and regional faulting associated with the subject site. Please include the names, distances, and potential magnitudes of faults potentially impacting the subject property. AGS Response: Regional faults in southernmost California typically trend northwest and display major right lateral slip with common smaller scale vertical displacements (Jennings, 1994). Significant faults of this system displaying Holocene offset are portions of the San Andreas, Elsinore, San Jacinto, and Coronado Bank Faults and the related Newport-Inglewood and Rose Canyon Faults. Of these, the offshore Rose Canyon Fault is the closest, being approximately 3.6 miles to the west. Recent studies have suggested the Rose Canyon Fault is considered as an extension of the Newport-Inglewood Fault. The Rose Canyon- Newport-Inglewood right-lateral fault is estimated to have an average slip rate of around 1 to 5 mm per year. Estimated moment magnitude for the Newport-Inglewood and Rose Canyon Faults is between 7.3 and 7.4 (Mw) if the rupture includes both the northerly onshore segments and southerly offshore segments, with a lesser magnitude if only the Rose Canyon portion were to rupture. The Julian Section of the Elsinore Fault, a right-lateral to reverse fault, is roughly 24 to 25 miles northeast of the site and is estimated to have an average slip rate of around 1 to 5 mm per year and is believed to have last ruptured in the late Quaternary. Estimated moment magnitude for rupture on the Elsinore Fault is between 6.5 and 7.5 (Mw). The Newport- Inglewood and Rose Canyon Fault Zones as well as other faults within the southern California and northern Baja California area are potential generators of significant ground motion at the site. October 6, 2022 Page 3 P/W 2107-12 Report No. 2107-12-B-7R ADVANCED GEOTECHNICAL SOLUTIONS, INC. Comment 23.f: Please clarify if all building pads associated with the development should be graded as required so that a minimum 3' of compacted fill underlies the entirety of each building pad. AGS Response: The proposed building pad grades as shown on the recent plans (Plate 1) indicates that most buildings pads are located in design fill or cut-fill transitions. AGS recommends that building pads be overexcavated so that a minimum of 3 feet of fill is provided across the building pad and extending 5 feet outside the building limits where possible. The overexcavation should be extended as needed to provide a minimum of 1 foot of fill below footings. Comment 23.g: Please clarify the remedial grading recommendations (depths and limits of removals, etc.) for hardscape areas associated with the development. AGS Response: AGS recommends that a minimum of 1 foot of compacted fill be provided below hardscape areas. Additionally, unsuitable soils removals should be conducted so that all loose fill, alluvium, and highly weathered Old Paralic deposits are removed to exposed competent materials. Comment 23.h: Please provide grading and foundation recommendations (limits of possible remedial grading, foundation setbacks, deepened foundations, etc.) to address the high-pressure gas line and associated easement that reportedly traverses the subject site. AGS Response: AGS has prepared three geologic cross sections showing the gas line, proposed improvements, geologic units, and proposed unsuitable soils removals. The location and elevation of the gas line was based the Utility Plan, which includes information on several potholes that were completed on the gas line. AGS has estimated the pipe’s elevation based on interpolating between the pothole locations. The proposed improvements within the easement include roadways, flatwork, parking, and landscape areas. Several utility lines are also proposed below the pipeline. Coordination with the operator of the pipeline will be necessary in order to construct these utilities. Buildings 5 and 6 are proposed as close as 5 feet from this pipeline as illustrated on Cross Section A-A’. Footings should be deepened so that the bottom of the footing is located below a 1:1 projection from the pipeline invert. This may impact the southwest corner of Building 6, where footings may need to be deepened to around 2 feet below pad grades. Removals should be initiated no closer than 2 feet from the pipeline and should extend at a 1:1 ratio, which should be approved by the pipeline operator. Proposed removals are shown on the cross-sections and show that the placement of 1 foot of fill below the footings is possible; however, the lateral extent of the removals may not extend 5 feet outside the building limits. Based on the modeled geologic conditions, which should be verified during grading, the limited lateral extent of removals is not anticipated to negatively impact the adjacent proposed structures. A retaining wall, up to roughly 3 feet in height, is proposed as close as 5 feet from the pipeline as illustrated on Cross Section B-B’. Although wall plans are not available, it is anticipated that the footing will not surcharge the pipeline. AGS should review the wall plans when available to verify this assumption. Design fills are proposed over portions of the pipeline and may extend up to roughly 6 feet in depth as illustrated on Cross-Section C-C’, which will place up to 9 feet of fill over the pipeline. Although the type of pipeline should be able to withstand the anticipated fill loading, the pipeline operator should approve the placement of additional fill. It is anticipated that the pipeline is bearing on Old Paralic Deposits. As such, the placement of additional fill is expected to cause negligible amounts of settlement below the pipeline. October 6, 2022 Page 4 P/W 2107-12 Report No. 2107-12-B-7R ADVANCED GEOTECHNICAL SOLUTIONS, INC. Limited removals should be conducted over the pipeline. If soft or yielding materials are encountered within this zone, additional recommendations should be provided at that time, such as the placement of a geotextile reinforcement, to mitigate potential settlement of the proposed flatwork and driveway improvements. Coordination with the pipeline operator will be needed to verify the types of equipment that can operate as well as the proposed grading that can occur within the easement. If the grading recommendations provided herein cannot be accomplished, additional or revised recommendations can be provided at that time. Comment 23.i: As soils with an expansion index (El) over 20 are considered expansive and require mitigation in accordance with Sections 1803.5.3 and 1808.6 of the 2019 CBC, please revise Table 6.4 (Conventional Slab On Grade Foundation Design) of the report or indicate the methods that are being recommended to address potential on-site expansive soils (El test results between 0 and 117) and satisfy the requirements of Section 1808.6. Please provide a statement that the foundation system for the proposed residential structures of the development will meet the requirements of Section 1808.6 of the 2019 California Building Code. AGS Response: Recommendations in the referenced report were provided for both conventionally reinforced foundations as well as post tensioned foundations. However, it is proposed to utilized post- tensioned foundations for the residential structures. The post-tensioned foundations should be designed based on as-graded soil conditions. Final foundation recommendations should be provided in the as-graded report. AGS provided recommendations for the anticipated as-graded conditions, which have assumed that the upper materials within the influence of the foundation will have a “Very Low” to “Medium” expansion potential. It should be noted that the import of fill materials is proposed. If materials with a “High” expansion potential are encountered during grading or imported and are placed within the influence of the foundations, revised foundation recommendations will be needed and the redesign of foundations may be necessary. The foundation recommendations provided in Section 6.4 are intended to meet the requirements of the 2019 CBC for expansive soils conditions but will not be used to design the residential foundations since the use of post-tensioned foundations is proposed. Foundation systems should be designed to meet the requirements Section 1808-6 of the 2019 CBC. The post-tensioned foundation systems have not yet been designed, so AGS cannot provide a statement that the foundation system will meet the requirements of Section 1808.6 of the CBC. Comment 23.j: Please confirm the recommended depth of the footings for the proposed residential structures of the development that are presented in Table 6.4 of the report (12" deep for both 2 and 3 story buildings) are appropriate for all anticipated geotechnical conditions at the site; please provide any revised recommendations if necessary. AGS Response: Footings bearing in compacted fill and at a depth of 12 inches are expected to have an allowable minimum bearing capacity of 2,000 psf. Footings should be a minimum of 18 inches deep for “Medium” expansion potential soils. These values are provided based on the anticipated depths of removals, overexcavations, and minimum fill depths. If unanticipated geotechnical conditions are encountered, additional recommendations can be provided at that time. October 6, 2022 Page 5 P/W 2107-12 Report No. 2107-12-B-7R ADVANCED GEOTECHNICAL SOLUTIONS, INC. Comment 23.k: The report provides foundation recommendations (both conventional and post-tension) for both "Low" and "Medium" expansion potentials and does not include the "High" expansion test result that is presented in the laboratory testing. Please discuss the basis for providing recommendations for only "Low" and "Medium" expansion potential. Please also discuss how the expansion index (low or medium) will be determined for the proposed development with respect to the preparation of the foundation plans and details for the proposed structures and improvements. AGS Response: As mentioned in the response to Comment 23.i., the residence structures will be supported on post-tensioned foundation systems. The foundations should be designed based on as-graded soil conditions. Final foundation recommendations should be provided in the as-graded report. AGS provided recommendations for the anticipated as-graded conditions, which have assumed that the upper materials within the influence of the foundation will have a “Very Low” to “Medium” expansion potential. Although an expansive clay layer was encountered, it is recommended that the overexcavation be conducted to remove this clay if encountered near the surface. However, design fills of around 4 to 5 feet are planned. Therefore, the top of the clay layer may be located upwards of 7 feet below design grades. AGS plans to use a weighted average to determine the PTI foundation design parameters as outlined in the Design of Post-Tensioned Slabs-on-Ground, Third Edition and related addendums design recommendations. It is not anticipated that the foundation design will be needed for a “High” expansion potential as a majority of the near surface soils are expected to have a “Very Low” to “Low” expansion potential. However, as mentioned in our response to Comment 23.i, if imported expansive soils or onsite highly expansive materials are placed near the surface and within the influence zone of the foundations, the foundations may need to be designed for a “High” expansion potential. Revised foundation plans may be needed if this occurs and delays during construction may occur. AGS plans to periodically sample the fill materials both during and post grading within the building pad areas in order to provide pad-by-pad foundation design recommendations. Testing may include expansion potential, Atterberg limits, and gradation. Comment 23.l: With respect to Table 6.5 (Post-Tensioned Design Parameters) of the report, please provide all geotechnical parameters (percent passing the #200 sieve, percent clay, plasticity index, Thornthwaite Moisture Index, modulus of subgrade reaction, etc.) for use in the post-tensioned slab design in accordance with PTI DC10.5 as necessary. AGS Response: The values of predicted lift are based on the procedures outlined in the Design of Post- Tensioned Slabs-on-Ground, Third Edition and related addendums. No corrections for vertical barriers at the edge of the slab or other corrections (e.g. horizontal barriers, tree roots, adjacent planters) are assumed. The values assume Post-Equilibrium conditions exist (as defined by the Post Tensioning Institute), and these conditions created during construction should be maintained throughout the life of the structure. The following geotechnical parameters were used when estimating the Em and ym values provided in Table 6.5 of the referenced report and should be verified based on as-graded conditions. Assumptions and design parameters for “Low” expansion potential: Constant Suction Depth of 9 feet; a Thornwaite value of -20; a Constant Suction Value of 3.9 pF; Final suction value 3.0 swell and 4.5 shrink; LL=25, PL=10, PI=15; %-200=15%, %-2u=5%; Ff= 1; Corrections for vertical barriers at edge of slab as indicated. No other corrections (such as tree roots under the slab or horizontal barriers) are assumed. October 6, 2022 Page 6 P/W 2107-12 Report No. 2107-12-B-7R ADVANCED GEOTECHNICAL SOLUTIONS, INC. Assumptions and design parameters for “Medium” expansion potential: Constant Suction of 9 feet; a Thornwaite value of -20; a Constant Suction Value of 3.9 pF; Final suction value 3.0 swell and 4.5 shrink; LL=45, PL=20, PI=25; %-200=50%, %-2u=20%; Ff= 1; Corrections for vertical barriers at edge of slab as indicated. No other corrections (such as tree roots under the slab or horizontal barriers) are assumed. Comment 23.m: Please clarify the recommended depth of retaining wall footings below lowest adjacent finish grade. AGS Response: Retaining wall foundation should be embedded a minimum of 18 inches below adjacent grades and deepened as necessary to comply the 2019 CBC for sloping conditions. Comment 23.n: Please clarify the recommended type of pipe (Sch. 40 PVC, SDR-35, etc.) that should be used for retaining wall subdrains. AGS Response: The drain pipe should be a minimum of 4 inches in diameter and perforated. The tallest retaining wall that AGS has noted on the plans is anticipated to be roughly 2 to 3 feet in height. However, the design plans have not been prepared at this time to denote the wall details. Wall drains should be capable of supporting the anticipated loading conditions. For relatively short walls with no surcharge loading, a triple wall drainage pipe may be used. Schedule 40 PVC or SDR-35 should be used where surcharge conditions, such as traffic loading, are present. Alternative systems such a J-Drain can be used and should be approved by the geotechnical consultant. Comment 23.o: Please clarify if steel reinforcing is recommended for hardscape improvements; provide recommendations as necessary. AGS Response: Consideration should be given to using steel reinforcement, such as a 6x6” W2.9 WWM placed mid-slab, especially if as-graded soil conditions indicate that flatwork areas may be underlain by expansive soils. Comment 23.p: Please provide a summary list of all geotechnical services that should be provided as part of the construction of this development. AGS Response: The geotechnical consultant of record should review the grading, retaining wall, foundation and improvement plans to verify of geotechnical design recommendations have been incorporated into the design. The geotechnical consultant should provide observation and testing during construction including: grading activities, trench backfill, presaturation of building pads, footing excavations, retaining wall drain placement and backfill, preparation of subgrade for flatwork and pavement areas, and observation and testing of aggregate base and asphalt concrete. October 6, 2022 Page 7 P/W 2107-12 Report No. 2107-12-B-7R ADVANCED GEOTECHNICAL SOLUTIONS, INC. Unless specifically superseded herein, the conclusions and recommendations presented in the referenced reports remain in effect. Geologic conditions should be verified during grading to evaluate whether the recommendations provided herein are applicable to the conditions exposed. The opportunity to be of service is sincerely appreciated. If you should have any questions, please do not hesitate to contact the undersigned. Respectfully Submitted, Advanced Geotechnical Solutions, Inc. ___________________________________ __________________________________ JOHN J. DONOVAN PAUL J. DERISI RCE 65051, RGE 2790, Reg. Exp. 6-30-23 CEG 2536, Reg. Exp. 5-31-23 2107-12-B-7R (Oct 6, 2022, Response to City Comments, Ponto Dr).docx Attached: Appendix - References and Copy of Review Sheet Plate 1- Geologic Map and Site Exploration Plan and Geologic Cross-Sections Distribution: (1) Addressee (pdf, hard copy) ADVANCED GEOTECHNICAL SOLUTIONS, INC. APPENDIX REFERENCES AND COPY OF REVIEW SHEET October 6, 2022 Page A-1 P/W 2107-12 Report No. 2107-12-B-7R ADVANCED GEOTECHNICAL SOLUTIONS, INC. APPENDIX REFERENCES AND COPY OF REVIEW SHEET Advanced Geotechnical Solutions, Inc. (2021). “Due Diligence Geotechnical Study, Proposed Multi- Family Residential Development, 7200-7590 Ponto Drive, Carlsbad, County of Orange, California,” dated December 3, 2021, Report No. 2107-12-B-2R. ---. (2022a). “Preliminary Geotechnical Investigation and Infiltration Study, Proposed Multi-Family Residential Development, 7200-7294 Ponto Drive, Carlsbad, California,” dated March 16, 2022, Report No. 2107-12-B-4. ---. (2022b). “Preliminary Infiltration Feasibility Study, Proposed Multi-Family Residential Development, 7200-7294 Ponto Drive, Carlsbad, California,” dated March 16, 2022, Report No. 2107-12-B-5. ---. (2022c). “Additional Comments, Feasibility of Onsite Infiltration, Proposed Multi-Family Residential Development, 7200-7294 Ponto Drive, Carlsbad, California,” dated August 18, 2022, Report No. 2107-12-B-6. City of Carlsbad, 2021, Storm Water Standard – BMP Design Manual, February 2016, Revised September 1, 2021, Edition. Geotechnics Incorporated. (2009). “Geotechnical Investigation, Hilton Carlsbad Beach Resort and Spa, Carlsbad, California,” dated April 24, 2009 (Project No. 0703-002-01, Document No. 09-0206). Group Delta. (2010a). “Response to Review Comments, Hilton Carlsbad Oceanfront Resort & Spa, Carlsbad, California,” dated May 10, 2010 (Document No. 10-0288, Project No. 0703-002-01. ---. (2010b). “Response to Request for Information, Hilton Carlsbad Oceanfront Resort, Carlsbad, California,” dated October 6, 2010 (Document No. 10-0526, Project No. SD-126. ---. (2010c). “Grading Plan Review, Hilton Carlsbad Oceanfront Resort & Spa, Carlsbad, California,” dated November 30, 2010 (Document No. 10-0601, Project No. SD-126. Jennings, C. W. (1994). “An Explanatory Text to Accompany the Fault Activity Map of California and Adjacent Areas.” California Division of Mines and Geology. ---. (1994) “Fault Activity Map of California and Adjacent Areas, with Locations and Ages of Recent Volcanic Eruptions.” California Division of Mines and Geology, Geologic Map No. 6, Scale 1:750,000. U.S. Geological Survey (USGS) and California Geological Survey (CGS), Quaternary fault and fold database for the United States, accessed September 2022. CROSS-SECTION A-A’ SCALE 1”=30’ H&V A A’ 0 30 60 EL E V A T I O N ( F E E T ) 90 Gas Line Bldg 5 (New) af ? TD 4’ TP-9 proj. 20’W Qop afu/Qal Bldg 6 (New) Removals Project: P/W 2107-12 Report:Date: Sep. 2022 and Geologic Cross Sections PLATE 1 Exploration Location Plan 2107-12-B-7 AGS LEGEND: Approximate location of hollow stem auger borings ( , 2021)AGS B-3 afu Artificial Fill - Undocumented AlluviumQal Approximate location of percolation ( , 2022)AGS P-2 TP-6 Approximate location of test pit ( , 2022)AGS Old Paralic DepositsQop Santiago FormationTsa A A’Geologic Cross Section Existing Grade Proposed Grade A A’ Approximate location of hollow stem auger borings ( cs Inc, 2009)Geotechni GI-B-4 Geologic Contact TP-1 B-2 B-1 P-1 B-3 B-3 0.0 - 4.0 ft. 4.0 - 16.5 ft. afu Qop T.D. 16.5 ft. No Water B-4 B-4 0.0 - 4.0 ft. 4.0 - 20.8 ft. afu Qop T.D. 20.8 ft. No Water B-5 B-5 0.0 - 6.0 ft. 6.0 - 16.5 ft. afu Qop T.D. 16.5 ft. No Water B-6 B-6 0.0 - 2.5 ft.afu Refusal @ 2.5 ft. No WaterB-7 B-7 0.0 - 2.5 ft. 2.5 - 5 ft. afu Qop T.D. 5 ft. No Water P-2 P-2 0.0 - 4.0 ft. 4.0 - 5.5 ft. T.D. 5.5 ft. No Water afu? Qop P-3P-3 0.0 - 1.0 ft. 1.0 - 5.0 ft. T.D. 5.0 ft. No Water Topsoil Qop P-4P-4 0.0 - 2.0 ft. 2.0 - 5.5 ft. T.D. 5.5 ft. No Water afu/Qal Qop P-5 P-5 0.0 - 4.0 ft. 4.0 - 5.5 ft. T.D. 5.5 ft. No Water afu Qop? TP-1 0.0 - 3.5 ft. 3.5 - 8.0 ft. T.D. 8.0 ft. No Water afu/Qal Qop TP-2 0.0 - 1.5 ft. 1.5 - 6.0 ft. T.D. 6.0 ft. No Water Qal Qop TP-3 0.0 - 1.5 ft. 1.5 - 4.0 ft. 4.0 - 6.0 ft. T.D. 6.0 ft. No Water afu Qal Qop TP-4 0.0 - 9.0 ft. 9.0 - 13.5 ft. T.D. 13.5 ft. No Water afu Qop TP-6 0.0 - 3.0 ft. 3.0 - 6.0 ft. T.D. 6.0 ft. No Water afu Qop TP-7 0.0 - 3.5 ft. 3.5 - 7.0 ft. T.D. 7.0 ft. No Water Qal Qop TP-10 0.0 - 5.0 ft. 5.0 - 5.5 ft. T.D. 5.5 ft. No Water afu Qop TP-5 0.0 - 2.5 ft. 2.5 - 5.0 ft. 5.0 - 12.5 ft. T.D. 12.5 ft. No Water afu Qal Qop TP-8 0.0 - 2.5 ft. 2.5 - 5.0 ft. 5.0 - 12.5 ft. T.D. 12.5 ft. No Water afu Qal Qop TP-9 0.0 - 0.5 ft. 0.5 - 3.5 ft. 3.5 - 4 ft. T.D. 4 ft. No Water afu Qal Qop TP-2 TP-3 TP-4 TP-8 TP-5 TP-7 TP-9 TP-10 TP-6 GAS LINE GI-B-6GI-B-6 0.0 - 6.0 ft. 6.0 - 18.0 ft. 18.0 - 49.5 ft. T.D. 49.5 ft. Water at 41 ft. afu/Qal Qop Tsa GI-B-4GI-B-4 0.0 - 6.0 ft. 6.0 - 17.5 ft. 17.5 - 19.0 ft. T.D. 19.0 ft. No Water afu Qop Tsa P-1 0.0 - 3.0 ft. 3.0 - 5.0 ft. T.D. 5.0 ft. No Water afu Qop B-2 0.0 - 4.0 ft. 4.0 - 21.5 ft. afu Qop T.D. 21.5 ft. Water at 20.5 ft. B-1 0.0 - 26.5 ft. T.D. 26.5 ft. No Water Qop A A’ B B ’ C C’ CROSS-SECTION B-B’ SCALE 1”=30’ H&V B B’ 0 30 60 EL E V A T I O N ( F E E T ) 90 Gas Line Bldg 9 (New) af ? TD 16.5’ B-3 proj. 25’N Qop afu Bldg 15 (New) Removals Bldg (Ex.) afu ? Wall 2-3’ CROSS-SECTION C-C’ SCALE 1”=30’ H&V C C’ 0 30 60 EL E V A T I O N ( F E E T ) 90 Gas Line Bldg 10 (New) af ?TD 5’ B-7 proj. 25’W Qop afu Removals Bldg (Ex.) Clay Layer ?? afu