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Home My WebLink AboutCDP 2017-0064; ; UPDATES GEOTECHNICAL REPORT FOR NEW, ONE-STORY, SECOND DWELLING UNIT AND DETACHED GARAGE; 2025-11-05EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. Sharon Slowik 3 960 Sunny hill Drive Carlsbad, California 92008 10925 HARTLEY ROAD, SUITE "I" SANTEE, CALIFORNIA 92071 TEL. 619-258-7901 November 5, 2025 Project No. 03-1106H6(A) Subject: Updated Geotechnical Report For New, One-Story, Second Dwelling Unit and Detached Garage 3960 Sunnyhill Drive Carlsbad, California 92008 References: See Attached Dear Ms. Slowik: In accordance with your request, we are pleased to submit this updated geotechnical report for the new, one-sory second dwelling unit and detached garage. We have reviewed the referenced updated geotechnical investigation report (Reference No. 4) and revisited the site. The recommendations presented in the referenced report have been partially modified to reflect changes in the standard of practice in the industry and to conform to the current California Building Code. These recommendations should be incorporated into the project design and construction. SITE CONDITIONS We revisited the site on October 2, 2025 . The site conditions are similar to those described in the referenced geotechnical report. However, an unpermitted wall was constructed and is now in the process of being permitted and then rebuilt. Accordingly, we did not consider it necessary to perform an additional subsurface exploration or soil testing. PROPOSED CONSTRUCTION The proposed new construction consists of a new keystone retaining wall to be built west of the existing second dwelling unit. SEISMIC DESIGN VALUES Updated seismic design values are presented on the attached Figure 1. This opportunity to be of service is appreciated. If you have any questions, or we can be of further service, please do not hesitate to call or contact us. Updated Geotechnical Report for New, One-Story, Second Dwelling Unit and Detached Garage 3%0 Sunnybill Drive Carlsbad, CA 92008 Respectfully Submitted, Mamadou Saliou Diallo, P .E. RCE 54071, GE 2704 Attachment: Figure I Pagel November 5, 2025 Project No. 03-1106H6(A) EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC Updated Geotechnical Report for New, One-Story, Second Dwelling Unit and Detached Garage Page3 3960 Sunnyhill Drive Carlsbad, CA 92008 November 5, 2025 Project No. 03-1106H6(A) FIGURE 1 SEISMIC DESIGN VALVES 3960 Sunnyhill Dr, Carlsbad, CA 92008, USA Latitude,' ,...,11 :~t ... .., 1 c;.--r,i.St,., 11"" ,"'l-11"1;1 n Date Design Code R•fennat Do<;unwnt Risk Category Site Clau Type Value Description (Datil) ::.l/5/2025. 12:28:03 Pl'~ ASCEl -12 II D Ss s, 1.16 0.37 The J<.1CE, spectral response accele-ra'1on at 0.2 seconds for S'lte C1ass. lK. in units ~f g. The MCER spectral response acceleration at 1 second for Site Class BC. ,n units of g. Ill SMs 1.41 Svs = 1.5 x 505, the Risk-Targeted Maximum Considered Earthquake (MCER) spectral response acceleration for short periods (of the two- period specrrum) and the user-spedfied Site Glass SM: 5Js 5)1 0.94 0.94 0.63 S,.,, = 1.5 x 51:,i the MCE,, spectra• <-esponse aculeration for 1 second {of the t,,'0-~rioo spe..."'trum) and the useMpecified Sile C!.ass. The design spectral response acceleration for short periods (of the two-period spectrum) and the user-specified Site Class, in units of g. The design spectral response acceleration for 1 second (of the two-period spectrum) and the user-specified Site Class, in units of 9 Type Value Description (Data Contd.) SDC D Seismic de~n c<ltegor:, P~ 0.54 PGAM, the Geometric-Mean Maximum Considered Earthquake (MC~) peak gro~nd acceleration for the user-specified Site Class in units of g Ts 0.666 Ts = S;:)1/So;, in seconds, for construction of the two-period design spectrum Tc 0.133 T; = 0.2 xT.1, in seco!>ds. for ccnstmcticn o'i~~e two-period ooig'l respoPSe spectrurr T 8 h th.€ lcng-peric,d transition period in seconds, fc r construc:'on of the two-p,e,<c,d design response spectrum EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC Updated Geotechnical Report for New, One-Story, Second Dwelling Unit and Detached Garage 3960 Sunnyhill Drive Carlsbad, CA 92008 REFERENCES Page4 November 5, 2025 Project No. 03-1106H6(A) 1. "Final As-Graded Soils Report for New, One-Story, Second Dwelling Unit and Detached Garage, 3960 Sunnyhill Drive, City of Carlsbad, California", Project No. 03-1106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated November 15, 2024. 2. "Observation of Footing Excavations for New, One-Story, Second Dwelling Unit and Detached Garage, 3960 Sunnyhill Drive, City of Carlsbad, California", Project No. 03-1106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated September 10, 2021 . 3. "Report of Fill Compaction Tests for New, One-Story, Second Dwelling Unit and Detached Garage, 3960 Sunnyhill Drive, City of Carlsbad, California", Project No. 03-1106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated September 8, 2021 . 4. "Updated Geotechnical Report for New, One-Story, Second Dwelling Unit and Detached Garage, 3960 Sunnyhill Drive, City of Carlsbad, California", Project No. 03-1106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated April 11, 2021 . EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. Sharon Slowik 3960 Sunny.hill Drive Carlsbad, California 92008 10925 HARTLEY ROAD9 SUITE "I" SANTEE, CALIFORNIA 92071 TEL.(619)258-7901 October 17, 2025 Project No. 03-1106H6(A) Subject: Review of Grading Plans for New, Keystone Retaining wan Second Dwelling Unit 3960 Sunnyhill Drive Carlsbad, California 92008 Reference: "Limited Site Investigation, ProJX)sed New Primary Residence, 3960 Sunnyhill Drive, City of Carlsbad, California", Project No. 03-1106H6{A), Prepared by East -County Soil Consultation and Engineering, Inc., Dated April 21, 2004. Dear Ms. Slowik: In accordance_ with your request, we have reviewed the new grading plans prepared by Engineering Design Group of San Marcos, California for the new keystone wall, located west of the second dwelling unit at the subject site. The grading plans were found to be in accordance with the recommendations presented in the referenced geotechnical report. Our firm. should observe the foundation excavations for proper size and embedment into competent bearing soils. If we can be of further assistance, please do not hesitate to contact our office. Respectfully Submitted, P.E. RCE 54071. GE 2704 EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC Sharon Slowik 3960 Sunnyhill Drive Carlsbad, California 92008 10925 HARTLEY ROAD, SUITE "I" SANTEE, CALIFORNIA 92071 619 258-7901 November 15, 2024 Project No. 03-1106H6(A) Subject: Final As-Graded Soils Report for New, One-Story, Second Dwelling Unit and Detached Garage 3%0 SunnyhiD Drive Carlsbad, California 92008 References: See Attached Dear Ms. Slowik: In accordance with your request, we have prepared this final, as-graded soil report for the proposed second dwelling unit and detached garage located at 3460 Roosevelt Street, in the City of Carlsbad, California. Based on our field observations and attached Report of Field Density Tests (see attached Reference No. 2), it is our opinion that the soil engineering and engineering geologic aspects of the site grading are in accordance with the referenced geotechnical reports (References No. 3 and 5), local grading ordinances and the project grading plans. In addition, the footing excavations, soil expansion characteristics and soil bearing capacity are all in conformance with the approved plans and specifications. This opportunity to be of service is appreciated. ff you have any questions, or we can be of further service, please do not hesitate to call or contact us. Respectfully Submitted, GE270 * EXP. \ £_-}l ·, Q~ '-. ... ...,t;J,:~ ·'::-!.,~ rtt/~~~~,-, ~~ Mamadou Saliou Diallo, P .E. RCE 54071, GE 2704 MSD\md Final-As-Graded Soils Report for New, One-Story, Second Dwelling Unit and Detached Garage 3960 Sunnyhill Drive Carlsbad, CA 92008 REFERENCES Page2 November 15, 2024 Project No. 03-1106H6(A) 1. "Observation of Footing Excavations for New, One-Story, Second Dwelling Unit and Detached Garage, 3960 Sunnyhill Drive, City of Carlsbad, California", Project No. 03-l 106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated September 10, 2021. 2. "Report of Fill Compaction Tests for New, One-Story, Second Dwelling Unit and Detached Garage, 3960 Sunnyhill Drive, City of Carlsbad, California", Project No. 03-l 106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated September 8, 2021. 3. "Updated Geotechnical Report for New, One-Story, Second Dwelling Unit and Detached Garage, 3960 Sunnyhill Drive, City of Carlsbad, California", Project No. 03-1106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated April 11 , 2021. 4. "Response to Third Party Review, Proposed Second Dwelling Unit, 3960 Sunnyhill Drive, City of Carlsbad, California", Project No. 03-1106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated July 23, 2019. 5. "Geotechnical Report Update, Proposed New Primary Residence, 3960 Sunnyhill Drive, City of Carlsbad, California", Project No. 03-1106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated August 8, 2017. 6. "Limited Site Investigation, Proposed New Primary Residence, 3960 Sunnyhill Drive, City of Carlsbad, California", Project No. 03-l 106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated April 21, 2004. 7. "Soil Bearing Value Recommendation, Proposed Second Story Addition, 3960 Sunnyhill Drive, City of Carlsbad, California", Project No. 03-l 106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated July 16, 2003. 2 EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. Sharon Slowik 3960 Sunnyhill Drive Carlsbad, California 92008 10925 HARTLEY ROAD, SUITE "I" SANTEE, CALIFORNIA 92071 TEL. 619-258-7901 September 8, 2021 Project No. 03-1106H6(A) Subject: Report of Fill Compaction Tests for New, One-Story, Second Dwelling Unit and Detached Garage 3960 Sunnyhill Drive Carlsbad, California 92008 References: See Attached Figure 2 Dear Ms. Slowik: This report presents the results of fill compaction tests performed on the building pad for the new, one-story second dwelling unit at the subject site. Site grading was conducted between August 9 and 24, 2021 under the observation and testing of a representative of East County Soil Consultation & Engineering Inc. The surface soils within the building area for the proposed second dwelling unit and to a distance of at least 5 feet outside building limits were removed and replaced with compacted fill to a depth of 3 feet. The detached garage is located in a "cut" area and will be founded in dense terrace deposits. Fill soils consisting of on-site silty sand were placed in 6 to 8-inch-thick lifts, moisture- conditioned to near optimum moisture content and compacted in excess of 90 percent relative compaction. Compaction was achieved with the aid of a track loader. In-place field density tests were performed on the compacted fill in accordance with ASTM D1556 (Sand Cone Method). The results of the field density tests and fill compaction values are presented on Table 1, Fill Compaction Test Results. Results of a laboratory maximum density tests of the fill soils are presented on Table 2, Laboratory Maximum Density Test Results. The approximate field density/fill compaction test locations are shown on Figure 1. Report of Fill Compaction Tests for New, One-Story, Second Dwelling Unit and Detached Garage 3960 Sunnybill Drive Carlsbad, CA 92008 Page 2 September 8, 2021 Project No. 03-1106H6(A) Based on our field observations and fill compaction test results, it is our opinion that the grading and fill compaction were performed in accordance with the referenced geotechnical report (Reference No. 4) and local grading ordinances. This opportunity to be of service is appreciated. If you have any questions, or we can be of further service, please do not hesitate to call or contact us. Respectfully Submitted, Martin R. Owen, PE, GE Geotechnical Engineer Attachments: Tables 1, 2 and Figures 1 and 2 EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. Report of Fill Compaction Tests for New, One-Story, Second Dwelling Unit and Detached Garage 3960 Sunnybill Drive Carlsbad, CA 92008 TABLE 1 FILL COMPACTION TEST RESULTS TEST SOIL FILL FIELD FIELD MAXIMUM NO. TYPE DEPTH MOISTURE DRY DRY (FEET) CONTENT DENSITY DENSITY (%) (PCF) (PCF) 1 1 2 8.9 123.1 130.0 2 1 2 8.2 118.7 130.0 3 1 2 9.1 124.5 130.0 4 1 1.5 8.7 120.9 130.0 5 1 3 FG 8.5 123.0 130.0 6 1 4FG 9.6 122.1 130.0 FG = FINISHED GRADE TABLE 2 Page 3 September 8, 2021 Project No. 03-1106H6(A) FILL COMPACTION (%) 95 91 96 93 95 94 LABORATORY MAXIMUM DENSITY TEST RESULTS ASTM D1557 SOIL SOIL MAXIMUM OPTIMUM TYP DESCRIPTION DRY DENSITY MOISTURE E (PCF) CONTENT (%) 1 DARK REDDISH BROWN, SIL TY SAND 130.0 8.0 EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. Report of Fill Compaction Tests for New, One-Story, Second Dwelling Unit and Detached Garage 3960 Sunnyhill Drive Carlsbad, CA 92008 FIGURE 1 Page 4 September 8, 2021 Project No. 03-l 106H6(A) LOCATIONS OF FIELD DENSITY/FILL COMPACTION TESTS C> No :5cA-CE EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. Report of Fill Compaction Tests for New, One-Story, Second Dwelling Unit and Detached Garage 3960 Sunnyhill Drive Carlsbad, CA 92008 FIGURE 2 REFERENCES Page 5 September 8, 2021 Project No. 03-1106H6(A) 1. "Updated Geotechnical Report for New, One-Story, Second Dwelling Unit and Detached Garage, 3960 Swmyhill Drive, City of Carlsbad, California", Project No. 03-1106H6(A), Prepared by East County Soil Consultation and Engineering, Inc ., Dated April 11, 2021. 2. "Response to Third Party Review, Proposed Second Dwelling Unit, 3960 Sunnyhill Drive, City of Carlsbad, California", Project No. 03-1106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated July 23, 2019. 3. "Geotechnical Report Update, Proposed New Primary Residence, 3960 Swmyhill Drive, City of Carlsbad, California", Project No. 03-1106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated August 8, 2017. 4. "Limited Site Investigation, Proposed New Primary Residence, 3960 Swmyhill Drive, City of Carlsbad, California", Project No. 03-1106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated April 21 , 2004. 5. "Soil Bearing Value Recommendation, Proposed Second Story Addition, 3960 Swmyhill Drive, City of Carlsbad, California", Project No. 03-1106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated July 16, 2003 . EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. Sharon Slowik 3960 Sunnyhill Drive Carlsbad, California 92008 10925 HARTLEY ROAD, SUITE "I" SANTEE, CALIFORNIA 92071 TEL. 619-258-7901 September 10, 2021 Project No. 03-1106H6(A) Subject: Observation of Footing Excavations for New, One-Story, Second Dwelling Unit and Detached Garage 3960 Sunnyhill Drive Carlsbad, California 92008 References: See Attached Figure 1 Dear Ms. Slowik: In accordance with your request, we have observed the footing excavations for the proposed one- story second dwelling unit and detached garage at the subject site. The footings have been excavated to the proper depth and width into competent soils and are in compliance with the approved building plans. Foundation excavations, soil expansion characteristics and soil bearing capacity are in accordance with the referenced geotechnical reports (Reference Nos. 2, 3 and 5). This opportunity to be of service is appreciated. If you have any questions, or we can be of further service, please do not hesitate to call or contact us. Respectfully Submitted, Martin R. Owen, PE, GE Geotechnical Engineer Attachment: Figure 1 Updated Geotechnical Report for New, One-Story, Second Dwelling Unit and Detached Garage 3960 Sunnyhill Drive Carlsbad, CA 92008 FIGURE 1 REFERENCES Page 2 September 10, 2021 Project No. 03-1106H6(A) 1. "Report of Fill Compaction Tests for New, One-Story, Second Dwelling Unit and Detached Garage, 3960 Sunnyhill Drive, City of Carlsbad, California", Project No. 03-1106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated September 8, 2021 . 2. "Updated Geotechnical Report for New, One-Story, Second Dwelling Unit and Detached Garage, 3960 Sunnyhill Drive, City of Carlsbad, California", Project No. 03-1106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated April 11, 2021. 3. "Response to Third Party Review, Proposed Second Dwelling Unit, 3960 Sunnyhill Drive, City of Carlsbad, California", Project No. 03-1106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated July 23 , 2019. 4. "Geotechnical Report Update, Proposed New Primary Residence, 3960 Sunnyhill Drive, City of Carlsbad, California", Project No. 03-1106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated August 8, 2017. 5. "Limited Site Investigation, Proposed New Primary Residence, 3960 Sunnyhill Drive, City of Carlsbad, California", Project No. 03-1106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated April 21, 2004. 6. "Soil Bearing Value Recommendation, Proposed Second Story Addition, 3960 Sunnyhill Drive, City of Carlsbad, California", Project No. 03-1106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated July 16, 2003. EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. Sharon Slowik 3960 Sunnyhill Drive Carlsbad, California 92008 10925 HARTLEY ROAD, SUITE "I" SANTEE, CALIFORNIA 92071 TEL. 619-258-7901 April 11 , 2021 Project No. 03-1106H6(A) Subject: Updated Geotechnical Report for New, One-Story, Second Dwelling Unit and Detached Garage 3960 Sunnyhill Drive Carlsbad, California 92008 Dear Ms. Slowik: In accordance with your request, we are pleased to submit this updated geotechnical report for the subject new, one-story, second dwelling unit and detached garage. We have reviewed the referenced Limited Site Investigation Report and Geo technical Report Update, dated April 21 , 2004 and July 23 , 2019, respectively (see attached Figure 1, References 2 and 3), and revisited the site . The recommendations presented in the referenced reports have been partially modified to reflect changes in the standard of practice in the industry and to conform to the current California Building Code. These recommendations should be incorporated into the project design and construction. SITE VISIT We revisited the site on April 6, 2021 . Conditions in the area of the proposed second dwelling unit and garage are similar to those described in the referenced geotechnical reports. Accordingly, we did not consider it necessary to perform additional subsurface exploration or soil testing. SEISMIC DESIGN VALUES Updated seismic design values are presented on the attached Figure 2. CONCLUSIONS The site is suitable for construction of the new, one-story, second dwelling unit and detached garage. The following updated footing and floor slab recommendations should be incorporated into the design and construction of the residence and garage, while the other recommendations presented in the referenced reports are still valid. Updated Geotechnical Report for New, One-Story, Second Dwelling Unit and Detached Garage 3960 Sunnyhill Drive Carlsbad, CA 92008 FOOTINGS Page 2 April 11, 2021 Project No. 03-1106H6(A) Continuous and/or individual footings should be founded in dense terrace deposits at a minimum depth of 18 inches below building pad grade or lowest adjacent, finished grade, whichever is deeper. Continuous footings should be reinforced with a minimum of four #4 steel bars, with two bars placed near the top of the footings and the other two bars placed near the bottom of the footings. Individual footings should be at least 18 inches square and reinforced with a grid of #4 bars spaced 12 inches on centers ( each way) and placed on concrete blocks at the bottom of the footing. FLOOR SLABS Floor slabs including garage slabs should be at least 5 inches thick and reinforced with #4 bars placed at 18 inches on centers in two directions in the middle of the slab . The reinforcing steel should be supported on steel chairs or concrete blocks. Floor slabs should be underlain by 2 inches of clean sand over a 10-mil visqueen moisture barrier over 2 inches of clean sand. To minimize the potential for shrinkage cracks, floor slab concrete should have a minimum compressive strength of 3,000 psi and maximum water-cement ratio of 0. 5.. No special inspection of concrete is necessary. Some shrinkage cracks are still possible. ADDffiONALSERVICES A review of plans and specifications, field observations and testing under our direction are integral parts of the recommendations made in this report. If East County Soil Consultation and Engineering, Inc. is not retained for these services, the client agrees to assume our responsibility for any potential claims that may arise during construction. Observation and testing are additional services, which are provided by our firm, and should be budgeted within the cost of development. This opportunity to be of service is appreciated. If you have any questions, or we can be of further service, please do not hesitate to call or contact us. Respectfully Submitted, Martin R. Owen, PE, GE Geotechnical Engineer Attachments: Figures 1 and 2 EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. Updated Geotechnical Report for New, One-Story, Second Dwelling Unit and Detached Garage 3960 Sunnyhill Drive Carlsbad, CA 92008 FIGURE 1 REFERENCES Page3 April 11 , 2021 Project No. 03-1106H6(A) 1. "Response to Third Party Review, Proposed Second Dwelling Unit, 3960 Sunnyhill Drive, City of Carlsbad, California", Project No. 03-1106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated July 23, 201 9. 2. "Geotechnical Report Update, Proposed New Primary Residence, 3960 Sunnyhill Drive, City of Carlsbad, California", Project No. 03-1106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated August 8, 2017. 3. "Limited Site Investigation, Proposed New Primary Residence, 3960 Sunnyhill Drive, City of Carlsbad, California", Project No. 03-1106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated April 21 , 2004. 4. "Soil Bearing Value Recommendation, Proposed Second Story Addition, 3960 Sunnyhill Drive, City of Carlsbad, California", Project No. 03-1106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated July 16, 2003 . EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. Updated Geotechnical Report for New, One-Story, Second Dwelling Unit and Detached Garage Page4 April 11, 2021 Project No. 03-1106H6(A) 3960 Sunnyhill Drive Carlsbad, CA 92008 FIGURE2 SEISMIC DESIGN V ALOES 3960 Sunnyhill Dr, Carlsbad, CA 92008, USA h,: J .1 -, Date Design Code Reference Document Risk Category Site Class Type Value Ss 1.02 S: 0.371 s,,,s 1.114 S,,n null -See Section 11.4.8 S::1s 0.742 SJ: null -See Section 11.4.8 Type Value soc null -See Section 11.4.8 F. 1.092 F, null -See Section 11.4.8 PGA 0.447 Description Description 4/9/2021, 2:48:47 PM ASCE7-16 11 D -Stiff Soil MCE~ ground motion. (for 0.2 second period) MCE" ground motion. (for 1.0s period) Site-modified spectral acceleration value Site-modified spectral acceleration value Numeric seismic design value at 0.2 second SA Numeric seismic design value at 1.0 second SA Seismic design category Site amplification factor at 0.2 second Site amplification factor at 1.0 second MCE,.; peak ground accelera ·on EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. Sharon Slowik 3 960 Sunny hill Drive Carlsbad, California 92008 10925 HARTLEY ROAD, SUITE "I" SANTEE, CALIFORNIA 92071 TEL. (619) 258-7901 Subject: Review of Grading Plan, Foundation Plan and Details Proposed Second Dwelling Unit 3 960 Sunny.hill Drive Carlsbad, California 92008 References: See Attached Dear Ms. Slowik: May 19, 2020 Project No. 03-l 106H6(A) In accordance with your request, we have reviewed the grading plan for the proposed second dwelling unit prepared by Engineering Design Group and the foundation plan and details prepared by Lovelace Engineering. The grading plan, foundation plan and details were found to be in accordance with the recommendations presented in the referenced geotechnical reports. Our firm should observe the foundation excavations for proper size and embedment into competent bearing soils. If we can be of further assistance, please do not hesitate to contact our office. Respectfully Submitted, Martin R. Owen, PE, GE Geotechnical Engineer SHARON SLOWIK/ 3960 SUNNYHILL DRIVE PROJECT NO. 03-J 106H6(A) REFERENCES 1. "Response to Third Party Review, Proposed Second Dwelling Unit, 3960 Sunnyhill Drive, City of Carlsbad, California", Project No. 03-1106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated July 23, 2019. 2. "Minor Grading Plan for Slowik Property" by Engineering Design Group, Dated May 2, 2019. 3. "Geotechnical Report Update, Proposed New Primary Residence, 3960 Sunnyhill Drive, City of Carlsbad, California", Project No. 03-1106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated August 8, 2017. 4. "Limited Site Investigation, Proposed New Primary Residence, 3960 Sunnyhill Drive, City of Carlsbad, California", Project No. 03-1106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated April 21 , 2004. 5. "Soil Bearing Value Recommendation, Proposed Second Story Addition, 3960 Sunnyhill Drive, City of Carlsbad, California", Project No. 03-1106H6(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated July 16, 2003. 2