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HomeMy WebLinkAboutGPA 2017-0003; OAKMONT OF CARLSBAD; FINAL TESTING AND OBSERVATION DURING SITE GRADING; 2006-08-30GEOCON INCO!ti'OHATF.D Project No. 06442-32-04A August 30, 2006 Techbilt Construction Company 3575 Kenyon Street San Diego, California 9211 0 Attention: Mr. Raul Guzman GEOTECHNICAL Subject: CARLSBAD OAKS NORTH BUSINESS PARK-PHASE 1 LOTS 1 THROUGH 9 Gentlemen: CARJ.SBAD, CALIFORNIA FINAL REPORT OF TESTING AND OBSERVATION SERVICES DURING SITE GRADING CONSULTANTS 0 In accordance with your request and our Proposal No. LG-05260 revison dated August I, 2005, we have provided testing and observation services during grading for Phase 1 of Carlsbad Oaks North Business Park, Lots l through 9. The site is located to the west of the intersection of Melrose Drive and Faraday A venue. The scope of our services included the following: • Observing the grading operation including the placement of compacted fill, the removal and/or processing of loose topsoil, alluvial deposits, landslide debris and undocumented fill placed by others; and the undercutting of formational material exposed al or near street subgrade to facilitate utility excavations. In addition, we observed the placement of several subdrain systems to verify proper installation. • Performing in-place density and moisture content tests in fill placed and compacted on the pads/lots and associated streets. • Performing laboratory tests to aid in evaluating the compaction, shear strength, and expansion characteristics of the soil material used as fill. In addition, the water-soluble sulfate content of randomly selected samples from finish grade was tested. • Preparing an As-Graded Geologic Map. • Preparing this final report of grading. 6960 Flander~ Drive ■ San Diego, California 92121-2974 ■ Telephone 18581 558-0900 ■ Fax (858) 556,6159 The purpose of this report is to document that the grading of the subject business park has been performed in substantial conformance with the recommendations of the project geotechnical report and subsequent consultations and that the fill materials have been properly compacted. At the time of this report, the grading for Lots 1, 2, and 6 was incomplete and an addendum report will be provided for these lots after completion. In addition, the density tests for portions of Lots 13 and 14 (Phase 2) that were part of the overall mass grading plan for Phase l have also been included herein. Grading operations for Phase l were perfonned concurrently with those for El Fuerte Street and Faraday A venue. Geotechnical information relating to the grading of these roads is presented in the following reports: • Final Repon of Testing and Observation Services During Roadway Grading, Carlsbad Oaks Nonh Business Park, Faraday Avenue Extension -StationJO+OO through 80+80, Carlsbad, California, prepared by Geocon Incorporated, dated July 27, 2006 (Project Nos. 06442-32· 05A and 06442-32-06A). • Final Repon of Testing and Observation Services During Site Grading, Carlsbad Oaks North Business Park, El Fuerte Street Extension -Station/0+00 through 38+00, Carlsbad, Calij0mia, prepared by Geocon Incorporated, dated July 13, 2006 (Project No. 06442-32~ 08A). An update geotechnical report presenting fine grading recommendations and geotechnical design criteria for the proposed ultimate development should be prepared by Geocon Incorporated once final plans have been prepared for the individual building pads. GENERAL The grading contractor for the project was Pinnick Incorporated of El Cajon, California. The project grading plans were prepared by O'Day Consultants, the project civil engineer, and are entitled Grading and Erosion Control Plans/or: Carlsbad Oaks North, Phase I, C.T. 97-13, City of Carlsbad approval dated October 26, 2004 (Drawing No. 415-9A). Recommendations for grading were provided in our report entitled Update Geotechnical Investigation, Carlsbad Oaks North. Business Park wul Faraday Avenue Offsite, Carlsbad, California, dated October 21, 2004 (Project No. 06442- 32-03). Staking and collection of the field survey infonnation was performed by O'Day Consultants. The exhibit used as a base map to present the as•graded geologic infonnation and in-place density test locations (Figures 1 through 4) is a copy of a compilation of digital information provided by O'Day Consultants. The map depicts the ultimate grading configuration with respect to lot lines, slope areas, lot numbers, and finish pad elevations. In addition, the existing ground topography prior to grading is shown. The base-of-fill elevations are also presented. This information was collected by surveyors from O'Day Consultants during remedial grading operations. The as-graded geologic contacts were Project No. 06442-32-04A -2-August 30, 2006 derived from intennittent field survey shots and estimates made by our field representatives based on survey and/or grade-checkers' stakes. In this regard, the contacts should be considered approximate. References to elevations and locations herein are based on as-graded survey information (remedial grading exhibits) provided by O'Day Consultants or grade-checkers' stakes in the field. Geocon Incorporated does not provide surveying services and, therefore, has no opinion regarding the accuracy of the as-graded elevations or sutface geometry with respect to the approved grading plans or proper surface drainage. GRADING Grading began with removing and exporting brush and vegetation from the areas to be graded. Topsoil, alluvium, landslide debris, and undocumented fill deposits were then removed to expose formational material. Within areas to receive fill, the exposed soil was then scarified, moisture conditioned and compacted. Fill materials from on-site excavations were then placed and compacted in layers until the design elevations were attained. The areas where hard rock or dense formational material was exposed at or near street subgrade were undercut approximately 7 feet to facilitate the excavations for underground utilities. The undercut criteria where formational materials exposed near finish grade of the building pads was detennined on a case-by-case basis by the owner, depending upon the apparent rippability of the materials exposed. Future excavations in areas where undercuts were not performed may encounter difficult digging and require breaking and/or localized blasting. Also, oversize material may be generated by the excavations and require special handling. Refer to the "As-Graded" Geologic Map (Figures 1 through 4) for the approximate delineation of formational areas. Fill Materials and Placement Procedures The on-site fill materials generally consisted of silty to clayey sands and sandy clays with mixtures of gravel and boulders generated from the various fonnational units exposed on site. In general, the upper IO feet of building pads and roadways were limited to oversize material less than 12 inches in maximum dimension and 6 inches in the upper 3 feet. Rock material greater than 12 inches was placed deeper than IO feet below proposed finish grade and at least 3 feet below the deepest utility. Fill materials classified as "soil-rock" mixtures were placed in some portions of the site by spreading and compacting the materials with a Caterpillar bulldozer in lifts 2 to 3 feet thick or less. Owing placement of each lift, the fill was unifonnly wheel-rolled with loaded rock trucks. These materials were heavily watered during spreading prior to compacting. Soil fills were placed in lifts no thick.er than would allow for adequate bonding and compaction. The soil was moisture conditioned, as necessary, and mixed during placement. Project No. 06442-32-04A - J -August 30, 2006 Field ln~Place Density and Laboratory Testing During grading, compaction procedures were observed and in-place density tests were performed to evaluate the relative compaction of the fill material. The in-place density tests were performed in general conformance with ASTM Test Method D 2922--01 (nuclear), Results of the field density tests and moisture content tests performed during grading are summarized on Table I and the approximate locations are presented on the "As-Graded" Geologic Map. In general, the in-place density test results indicate that the fill at the locations tested has a relative compaction of at least 90 percent and an appropriate moisture content. Laboratory tests were perfom1ed on samples of material used for fill to evaluate moisture-density relationships, optimum moisture content and maximum dry density (ASTM D 1557-02), expansion characteristics (ASTM D 4829--03), sulfate potential (CA Test No. 417) and shear strength (ASTM D 308~3). Laboratory testing for Phase I (Lots 1 through 9) was performed concurrently with the grading for Faraday Avenue and El Fuerte Street; as such, the sample numbers are not in consecutive order. The results of the laboratory tests that are applicable to the subject grading are summarized on Tables II through V. Slopes Cut and fill slopes were graded at design inclinations of 2: 1 (horizontal:vertical) or flatter, with maximum heights of approximately 70 feet. Slopes that exposed potentially adverse conditions (e.g., weak siltstones and claystones, erosive soils, extensive seepage, etc.) were provided with a stability fill. The area where a stability fill was constructed is shown on the "As-Graded" Geologic Map. In general, fill slopes were either over-filled and cut back or track-walked with a bulldozer during grading. Fill slopes comprised of clayier soil may be prone to surficial loosening due to cyclical wetting and drying and may require increased maintenance. All slopes should be planted, drained, and maintained to reduce erosion. Slope irrigation should be kept to a minimum to just support the vegetative cover. Surface drainage should not be allowed to flow over the top of the slope. Stabilization FIii Slopes A drained stabilization fill was constructed behind Lot 2 to reduce the potential of surficial slope instability due to the presence of weak claystone and siltstone materials and extensive seepage. In general, a 1: l (horizontal:vertical) backcut was initiated beyond the top of slope and was extended below pad grade. A heel drain and panel drain system was installed to collect the seepage encountered along the temporary backcut. The excavation was then was backfilled with compacted granular fill material. Figure 5, Geologic Cross Section A-A', shows the approximate limits of the stability fill. Project No. 06442-32-04A -4-August 30, 2006 Subdralns (General) Two types of subdrains were constructed in accordance with our recommendations. The systems consisted of a stability fill backdrain and canyon subdrains. The subdrain locations were surveyed by the project civil engineer and the locations are presented on the "As-Graded" Geologic Map. Additional discussion regarding the construction of the drainage systems is provided below. The final segment of subdrains consisted of non-perforated drainage pipe provided with a concrete cut-off wall constructed at the perforated/non-perforated interface. It is recommended that all subdrain outlets that empty into open space or brow ditches be provided with a headwall structure to protect the end of the pipe from damage or burial. Stability FIii Backdralns The stability fill constructed on the nonh facing slope behind Lot 2 was provided with a drain system consisting of 4-foot-wide Mirafi drainage panels positioned approximately 20 to 30 feet on center and vertically oriented against the temporary backcut and connected to a heel drain at the bottom. The heel drain consisted of an 8-inch-diameter perforated PVC pipe surrounded by ¾-inch, open-graded gravel wrapped in filter fabric. The heel drain was extended to the west and east along the stability fill backcut and ultimately connected to a storm drain box structure located outside of the toe of slope at El Fuerte Street approximate Station 17+ 75 and into the brow ditch situated on the west side of Lot 2. In addition, heel drain cleanouts were installed along the stability fill backcut in the event that future maintenance is necessary. The cleanouts were capped at the finish ground surface and their locations have been shown on the "As-Graded" Geologic Map. Canyon Subdrains Typical canyon subdrains consisting of 8-inch, perforated PVC pipe encapsulated in gravel and filter fabric were placed at the base of the remedial excavations where a depression occurred in the bedrock topography. Some of the original subdrain alignments were later diverted due to conflicts with underground utilities in Faraday A venue which were not known during the initial placement of the subdrain system. Finish Grade Soll Conditions Observations and laboratory test results indicate that prevailing soils randomly sampled (for Lots 3, 4, 5, 7 and 8) at finish grade have an Expansion Index (EI) ranging from O to 2 and are classified as having a "very low" expansion potential (El of 20 or less) as defined by Uniform Building Code (UBC) Table 18-1-B. The expansion condition for the lots in an interim condition will be provided upon completion of grading. Table ID presents the results of the expansion classification for the prevailing soils at finish grade. Project No. 06442-32-04-A • 5 • August 30, 2006 Oversize fragments and rock materials were generated from excavations during the grading operation. To the extent possible, the oversize material was placed within the "hold down" areas as previously discussed. The potential for encountering oversiz.e materials (12 inches or greater) should be considered if deep excavations (10 feet or more) are proposed (i.e., underground utilities, etc.). Although particular attention was given to restricting the oversize material to the placement zones described previously, some randomly occurring fragments larger than 12 inches in nominal diameter may be present in the upper portions of 611 areas. The performance of the fill, however, should not be adversely affected and the grading performed is considered to be in substantial conformance with our recommendations. Corrosion Laboratory tests perfonned on random soil samples to measure the percentage of water-soluble sulfate of the compacted fill at finish grade for Lots 3 through 5, and 7 and 8 indicate that the on-site materials possess a "negligible" to "moderate" potential for sulfate exposure to concrete structures, as defined by UBC Table 19-A-4. Table V presents the results of the water-soluble sulfate for the various lots sampled (Lots 3, 4, 5, 7, and 8). Geocon Incorporated does not practice in the field of corrosion engineering. Therefore, it is recommended that further evaluation by a corrosion engineer be perfonned if improvements are planned that are susceptible to corrosion. SOIL AND GEOLOGIC CONDITIONS In general, the soil and geologic conditions encountered during grading were found to be similar to those described in the referenced project geotechnical report. The enclosed "As-Graded" Geologic Map (Figures l through 4) depicts the general geologic conditions observed. Information provided by the project paleontologist was utilized in identifying the geologic units. Figure 5 (Geologic Cross Section A-A') represents the general geometry of the stability fill. The figures have been annotated to show a general representation of the as-graded geologic conditions observed during grading. Geologic contacts should be considered approximate. No geologic conditions were observed during grading that would preclude the continued development of the lots. CONCLUSIONS AND RECOMMENDATIONS 1.0 General 1.1 Based on observations and test results, it is the opinion of Geocon Incorporated that the grading, which is the subject of this report, has been performed in substantial conformance with the recommendations of the referenced project soil reports. Soil and geologic conditions encountered during grading that differ from those anticipated by the project soil Project No. 06442-32-04A • 6-August 30, 2006 report are not uncommon. Where such conditions required a significant modification to the recommendations of the project soil report, they have been described herein. 1.2 No soil or geologic conditions were observed during grading that would preclude the continued development of the property as planned. Based upon laboratory test results and field observations, it is our opinion that the fill soils within the subject lots and associated streets have generally been compacted to at least 90 percent relative compaction at the locations tested. 1.3 Fine grading and construction of utilities/foundations may encounter non-rippable formational material and/or generate some concretionary fragments and/or rock material 12 inches or greater in situ. Deeper excavations within the fill (10 feet or greater) for improvements such as utility lines, loading docks, etc., may also encounter oversize material (12 inches or greater). The potential for these conditions should be taken into consideration when detennining the type of equipment to utilize for future excavation operations. The oversize material may require special handling techniques and exportation. 1.4 It is not uncommon for groundwater or seepage conditions to develop where none previously existed, particularly after landscape irrigation is initiated. The occurrence of induced groundwater seepage from landscaping can be greatly reduced by implementing and monitoring a landscape program that limits irrigation to that sufficient to support the vegetative cover without ovetwatering. Shallow subdrains may be required in the future if seeps occur after rainy periods or after landscaping is installed. 1.5 References to the thickness and extent of rock hold-down areas within roadways or capping of building pads are approximate and were based upon the finish grade elevations of the approved referenced grading plans. 2.0 Drainage 2.1 Adequate drainage provisions are imperative. Under no circumstances should water be allowed to pond adjacent to footings. The building pads should be properly finish graded after the buildings and other improvements are in place so that drainage water is directed away from foundations, pavements, concrete slabs, and slope tops to controlled drainage devices. Project No. 06442-32-04A . 7. August 30, 2006 3.0 Update Geotechnlcal Report 3.1 An update geotechnical report presenting fine-grading recommendations and geotechnical design criteria should be prepared by Geocon Incorporated once the final development plans have been prepared for the subject lots. LIMITATIONS The conclusions and recommendations contained herein apply only to our work with respect to grading and represent conditions at the date of our final observation of grading operations on June 13, 2006. Any subsequent grading should be done in conjunction with our observation and testing services. As used herein, the term "observation" implies only that we observed the progress of the work with which we agreed to be involved. Our services did not include the evaluation or identification of the potential presence of hazardous materials. Our conclusions and opinions as to whether the work essentially complies with the job specifications are based on our observations, experience and test results. Due to the inaccuracies inherent in most field and laboratory soil tests, and the necessary assumption that the relatively small soil sample tested is representative of a significantly larger volume of soil, future tests of the same soil location or condition should not be expected to duplicate specific individual test results of this report. Subsurface conditions, and the accuracy of tests used to measure such conditions, can vary greatly at any time. We make no warranty, express or implied, except that our services were perfonned in accordance with engineering principles generally accepted at this time and location. We will accept no responsibility for any subsequent changes made to the site by others, by the uncontrolled action of water, or by the failure of others to properly repair damages caused by the uncontrolled action of water. It is the responsibility of Techbilt Construction Company to ensure that the information and recommendations contained herein are brought to the attention of the architect and engineer for the project, are incorporated into the plans, and that the necessary steps are taken to see that the contractor and subcontractors carry out such recommendations in the field. Recommendations that pertain to the future maintenance and care for the property should be brought to the attention of future owners of the property or portions thereof. The findings and recommendations of this report may be invalidated wholly or partia1ly by changes outside our control. Therefore, this report is subject to review and should not be relied upon after a period of three years. Project No. 06442-32-04A . 8. August 30, 2006 TABLE I SUMMARY OF FIELO OENSITY TEST RESULTS Elev. Plus Field Field Field Req'd. " 314" D,y Moist Rel. Rel. Depth C= Rock Defil. Cont. Comp. Comp. Test No. D"' Location (ft) No. (%) (pcO (%) (%) (%) 46 07126'05 Lot 6 349 3 0 115.2 11.4 90 90 47 07 /26/05 Lot 6 349 3 0 120.4 12.2 94 90 48 07/26105 Lot 6 350 3 0 116.5 94 91 90 49 07(26/05 Lot 6 343 2 0 122.8 9.0 94 90 50 07/27/05 Lot 6 352 3 0 118.7 9.5 93 90 ------··------·--·-············-------····-······· 51 07127/05 Lot 6 352 3 0 116.4 10.7 91 90 52 rn12110s 1..o1 6 35( 3 0 117.5 9.4 92 90 53 07/27/05 Lot 6 333 3 0 124.9 10.9 98 90 54 07127/05 Lot 6 350 3 0 115.6 12.0 90 90 55 07(17/05 Lot 6 353 3 0 118.8 9.2 93 90 56 07127/05 Loi 6 330 3 0 116.5 9.6 91 90 57 07/28/05 lot l 255 3 0 117.4 9.6 92 90 58 07128/05 Lot I 249 3 0 115.2 9.9 90 90 59 07/28/05 Lot 6 336 2 0 119.8 8.4 92 90 60 07 /28/05 Lot 6 340 2 0 122.4 9.3 94 90 -----------·········-··· 61 07/28/05 Lot 6 358 2 0 ll7.l 9.5 90 90 62 07128/05 Lot6 333 2 0 117.2 8.7 90 90 63 08/01/05 Lot 8 325 3 0 118.7 10.4 93 90 64 08/02/05 Lot 8 3!0 3 0 117.4 9.1 92 90 65 08/02/05 Lot 8 313 3 0 I 16.5 8.9 91 90 -----------······· --------------·-··········-·· --·------·················-· 66 08/02/05 Lot 8 315 3 0 115.2 10.2 90 90 67 08/02/05 Lot 8 317 3 0 115.9 11.4 91 90 68 08/03/05 Lot 8 327 3 0 117.8 9.3 92 90 69 08/03/05 Lot 8 325 3 0 115.5 10.4 90 90 70 08/03/05 Lot 8 330 3 0 121.3 9.7 95 90 • ···-········--··--·· 71 08/03/05 Lot 8 332 3 0 118.2 10.2 92 90 72 08/03/05 Lot 8 336 3 0 115.2 l0.5 90 90 73 08/03/05 Lot 8 334 3 0 116.7 l0.0 91 90 74 08/03/05 Lot 8 336 3 0 121.6 9.4 95 90 75 08103/05 Lot 8 316 3 0 118.9 9.0 93 90 -------········· ··-------------·-··············· 76 08/04/05 Lot 8 318 3 0 115.3 9.0 90 90 77 08/04/05 Lot 8 322 3 0 120.l 8.9 94 90 78 08/04/05 Lot 8 314 3 0 124.4 9.7 97 90 79 08/04/05 Lot 8 319 3 0 116.0 10.4 91 90 80 08/04/05 Lot 8 322 3 0 118.0 10.2 92 90 ..... 81 08/04/05 Lot 8 325 3 0 115.2 8.5 90 90 82 08/04/05 Lot 8 327 3 0 118.7 8.8 93 90 83 08/04/05 Lot 6 355 2 0 120.0 9.0 92 90 84 08/04/05 Lot 6 356 2 0 118.7 9.4 91 90 85 08/05/05 Lot 6 356 2 0 121.0 8.4 93 90 -··········""-------······ ..... ----------··········· --------·············· -------··················--- 86 08/05/05 Lot 6 357 2 0 123.9 8.5 95 90 87 08/05/05 Lot 6 358 2 0 ll7.2 9.0 90 90 88 08/05/05 Lot 6 358 2 0 118.0 9.1 91 90 89 08/05/05 Lot 6 359 2 0 122.0 8.9 94 90 90 08/05/05 Lot 6 348 2 0 I 19.4 8.3 92 90 ProJCCt No. 06442-32-04-A August 30, 2006 TABLE! SUMMARY OF FIELD DENSITY TEST RESULTS Elev. Plus Field Field Field Req'd °' 3/4" Dry Moist Rel. Rel. D<plh cu~, Rock °""'· Cont Comp. Comp. Test No. Dm location (ft) No. (%) (pcQ (%) (%) (%) 91 08/08/05 Lot 6 335 2 0 122.6 8.7 94 90 92 08/08/05 Lot 6 341 2 0 121.4 8.9 93 90 93 08/08/05 Lot 6 346 2 0 118.0 9.1 91 90 94 08/09/05 Lot 5 305 3 0 120.0 9.7 94 90 95 08/09/05 Lot 5 308 3 0 IIS.2 10.0 90 90 --·---------------------96 08/10/05 Lot 5 309 3 0 IIS.8 12.2 93 90 97 08/10/05 Lot 5 313 3 0 115.3 11.4 90 90 98 08/10/05 Lot 5 317 3 0 ll8.J 9.3 92 90 99 08/ I 0/05 Lot 5 320 3 0 123.1 10.5 96 90 100 08/10/05 Lot 1 255 3 0 115.5 11.3 90 90 --·--· IOI 08/10/05 lot I 259 3 0 117.5 10.2 92 90 102 08/ 11/05 Lot 5 320 0 117.3 11.4 91 90 103 08/1 l/05 Lot 5 321 0 121.7 9.8 94 90 104 08/1 1/05 Lot 5 324 4 0 112.4 13.7 91 90 105 08111/05 Lot 5 324 4 0 111.6 12.9 90 90 -·-------------------------------------------·· 106 08/11/05 Lot 5 326 4 0 116.2 13.9 94 90 !07 08111105 Whiptail Loop 62+00 342 3 0 ll8.8 9.7 93 90 108 08/11/05 Whiptail Loop 63+30 328 3 0 116.0 10.2 91 90 109 08111/05 Lot 8 335 3 0 120.3 9.5 94 90 110 ----~(!.~-~--~-~l:'~~-~r-~?~. 356 3 0 117.0 10.3 91 90 ·--·--··---------------------------------··· Ill 08/12/05 Lot 8 338 3 0 115.2 9.6 90 90 112 08/12/05 Lot 5 329 2 0 125.9 9.5 97 90 113 08/12/05 Lot5 334 2 0 t19.3 8.9 92 90 114 08/12/05 Lot 5 332 2 0 118.4 8.5 91 90 115 08/12/05 Lot 6 336 2 0 117.l 8.9 90 90 ... ·-------------------------116 08/15/05 Lot 3 269 0 117.9 9.1 91 90 117 08/15/05 Lot3 271 0 l 16.3 8.7 90 90 118 08/1S/05 Lot3 275 I 0 I 18.6 9.6 92 90 119 08/16/05 Lot3 272 2 0 118.1 9.4 91 90 120 08/16/05 Lot3 285 2 0 119.7 10.0 92 90 ----------············· ········-121 08116/05 Future Park Site 235 4 0 111.6 13.6 90 90 122 08/16/05 Future Park Site 237 4 0 116.3 14.8 94 90 123 08/16/05 Lot 3 275 2 0 122.6 8_5 94 90 124 08/16/05 Future Park Site 242 4 0 115.0 12.7 93 90 125 08/17105 Lot l 245 4 0 112.3 15.5 91 90 126 08117/05 Lot l 247 4 0 111.6 16.0 90 90 127 08/17/05 LotS 328 2 0 117.1 8.2 90 90 128 08/17/05 LotS 330 2 0 123.3 8.5 95 90 129 08/18/05 Whiptail Loop 59+25 373 2 0 119.6 9.3 92 90 130 08118/05 Lot7 387 2 0 122.3 9.0 94 90 -·------------····'"············ 131 08/18/05 l.ot7 389 2 0 117.6 9.0 90 90 132 08/18/05 l.ot7 394 2 0 120.0 8.7 92 90 ST 133 08/18/05 Lot I 250 2 0 119.6 8.9 92 90 ST 134 08118/05 Loll 250 2 0 121.0 9.0 93 90 135 08/18/05 Lot 8 335 2 0 118.5 9.4 91 90 Project No. 06442-32-04A August 30. 2006 TABLE I SUMMARY OF FIELD DENSITY TEST RESULTS Elev. Plus Field Field Field Req'd. o, 3/4" Dry Moist Rel. Rel. O.plh C=< Rook Dens. Cont. Comp. Comp. Test No. °"' Location (ft) No. (%) (pen (%) (%) (%) 136 08/18105 Lot 8 340 2 0 117.6 8.3 90 90 137 08/18/05 Lot 8 338 2 0 117.4 8.5 90 90 138 08/18/05 Whiptai!Loop60+JO 360 2 0 119.3 8.9 92 90 139 08/18/05 Lot 8 342 2 0 118.0 JO.I 91 90 140 08118/05 Lot 6 353 2 0 123.3 8.5 95 90 -----· 141 08J 18/05 Lot 6 353 2 0 123.3 8.5 95 90 142 08/22/05 Lot 8 338 2 0 120.7 8.7 93 90 143 08/22/05 Lot 8 332 2 0 117.4 9.3 90 90 144 08/22J05 Lot 8 340 2 0 118.6 l0.7 91 90 145 08/22/05 Lot 8 341 2 122.7 10.0 94 90 ........ 146 08122/05 Lot 8 342 2 120.2 9.7 92 90 147 08/22/05 Lot 8 344 2 0 117.1 10.4 90 90 148 08/23!05 Lot 8 342 2 0 123.3 9.0 95 90 149 08/23/05 Lot 8 340 2 0 118.7 8.3 91 90 ISO 08/23/05 Future Park Sile 246 4 0 116.7 13.5 94 90 .............. ----------···············--------------··········--········--- ISi 08/23/05 Lot I 252 4 0 114.J 12.5 92 90 152 08/23/05 Future Park Site 250 4 0 111.6 13.0 90 90 153 08/23/05 Lot 8 343 2 0 I 17.6 8.3 90 90 154 08/23/05 Lot 8 342 2 0 118.8 8.9 91 90 155 08/24105 Lot 8 325 0 120.6 8.7 93 90 ------- 156 08/24/05 Lot 8 327 0 123.9 8.8 95 90 157 08/24/05 Lot 8 345 2 0 117.l 9.0 90 90 ST 158 08/24/05 Lot l 243 I 0 117.1 8.2 91 90 ST 159 08/24105 Lot I 240 I 0 116.3 8.0 90 90 160 08/25/05 Lot 3 279 0 IIS.5 12.0 92 90 ... 161 08/25/05 Lot 3 280 I 0 116.4 9.1 90 90 162 08/25/05 Lot 6 350 2 0 117.2 9.0 90 90 163 08/25/05 Lot 6 351 2 0 122.2 9.9 94 90 164 08/25105 Lot 8 328 2 0 118.5 10.0 91 90 165 08/25/05 Lot 3 282 116.8 8.7 91 90 --------------·--·-····-.................. 166 08/25/05 Lot 3 285 119.3 9.4 92 90 167 08/25/05 Lot 5 334 0 116.3 8.3 90 90 168 08/25/05 Lot 5 333 0 121.4 9.6 94 90 169 08/26/05 Lot 3 288 4 0 111.6 12.5 90 90 170 08/26105 Lot 3 288 4 0 112.4 11.8 91 90 ----------·-··············· ---------------------------·--······-······· ----······-·-·····-······· 171 08/26f05 Lot 3 295 4 0 ll5.0 12.7 93 90 172 08/26/05 Lot 3 293 4 0 112.0 11.4 90 90 173 08/26/05 Lot 3 295 4 0 114.2 12.2 92 90 174 08/26/05 Lot 3 298 4 0 111.7 11.4 90 90 175 08/26/05 Lot 5 315 2 0 121.0 9.2 93 90 .. ------------ 176 08/29/05 Lot 5 30& I 0 116.2 9.9 90 90 177 08/29/05 Lot 5 311 I 0 116.7 9.3 90 90 178 08/29/05 Lot 5 332 2 0 l 18.7 8.8 91 90 179 08/29/05 Lot 5 335 2 0 120.4 9.0 93 90 180 08/29/05 Lot 5 309 0 115.3 4.6 89 90 Project No. 06442-32-04A August 30, 2006 TABLE I SUMMARY OF FIELD DENSITY TEST RESULTS Elev. Plus Field Field Field Req'd. o, 3/4" Dry Moist. Rel. Rd. D<pth Cum Rock D<os. Corn. Comp. Comp. Test No. Oat, Location (ft) No. (%) (poO (%) (%) (%) 180A 08/29/05 Lot 5 309 0 I 19.2 IO.I 92 90 181 08/29/05 Lot 5 324 0 114.8 6.1 89 90 181 A 08/29/05 Lot 5 324 0 117.4 8.6 91 90 182 08n9/05 l.Dt5 318 0 122.6 7.8 95 90 183 08/29/05 Lot 5 334 0 122.1 7.6 95 90 ----------------------- FG 184 08/29/05 Lot I 260 0 117.4 7.2 91 90 FO 185 08129/05 Lot I 263 0 116.8 7.0 91 90 186 08/30/05 Lot 3 308 2 0 120.1 7.8 92 90 187 08/30/05 Lot 3; North 309 2 0 119.8 7.9 92 90 188 08/30/05 Lot 5 317 2 0 120.8 8.0 93 90 ..................................... 189 08/30/05 Lot 5 324 2 0 Il6.6 5.5 90 90 189A 08/30/05 Lot 5 324 2 0 119.0 8.0 91 90 190 08/30/05 Lot 5 326 2 0 118.9 6.1 91 90 190A 08/30/05 Loe 5 326 2 0 122.6 8.4 94 90 191 08/30/05 Lot 5 333 2 0 120.1 6.8 92 90 191 A 08/30/05 Lot 5 333 2 0 121.3 8.1 93 90 192 08130/05 Lot 5 334 0 122.7 I I.I 95 90 193 08/30/05 Lot S 326 0 124.7 9.3 97 90 194 08/31/05 Lot 5 332 2 0 120.2 8.3 92 90 195 08/31/05 Lot 5 333 2 0 123.1 9.7 95 90 196 08/31/05 Lot 4 416 2 0 119.2 11.4 92 90 197 08/31 /05 l..ot 4 425 4 0 116.5 8.2 94 90 198 08/31/05 Lot 4 428 2 0 120.l 9.6 92 90 199 08/31!05 Lot 5 337 2 0 114.l 5.5 88 90 199A 08/31 /05 Lot 5 337 2 0 117.9 10.5 90 ---. -.. -. -. 200 08/31/05 Lot 4 430 2 0 118.9 7.8 90 201 08/31105 Lot 5 337 2 0 120.4 8.8 93 90 202 09/01/05 Lot 5 335 2 0 120.5 9.5 93 90 203 09/01105 Lot 5 335 2 0 119.6 9.5 92 90 204 09/0 I /05 Lot 5 440 2 0 120.9 10.5 93 90 --------------------------· --·-- 205 09/01/05 Lot 5 441 2 0 122.9 10.0 94 90 206 09/01/05 Lot 3 297 4 0 113.6 14.6 92 90 207 09/01/05 Lot 3 298 2 0 120.\ 90 92 90 208 09/01/05 Lot 3 297 2 0 118.0 9.2 91 90 209 09/01/05 Lot 3 299 2 0 118.9 8.8 91 90 .. ····-·-···········-· 210 09/01J05 Lot 3 JOO 2 0 121.0 9.0 93 90 211 09/01105 Lot 3 299 2 0 122.2 7.6 94 90 212 09/01105 Lot 3 295 2 0 117.4 8.8 90 90 213 09/01/05 Lot 3 301 2 0 I 18.8 8.6 91 90 214 09/02/05 Lot 3 302 2 0 120.0 8.9 92 90 215 09/02/05 Lot 3 310 2 0 117.4 8.0 90 90 216 09/02/05 Lot 3; North 311 2 0 117.1 7.9 90 90 217 09/06/05 Lot 3 312 2 0 120.S 9.6 93 90 218 09/06/05 Lot 3; North 314 2 0 122.7 8.6 94 90 219 09/06/05 Lot 3 315 2 0 121.4 9.8 93 90 Project No. 06442-32-04A August 30, 2006 TABLE I SUMMARY OF FIELD DENSITY TEST RESULTS Elev. Pim Field Field Field Req'd. o, 3/4" Dry Moist. Rd. Rel. lkpth C=o Rock Dens. Cont. Comp. Comp. Test No. D,t, Location (ft] No. (%) (p<,Q (%) (%) (%] 220 09/06/05 Lot 3; North 317 2 0 124.6 8.7 96 90 221 09/06/05 Lot3 316 2 0 121.9 9.5 94 90 222 09/06/05 Lot3; Nonh 318 2 0 123.7 8.7 95 90 223 09/06/05 Lot3 JOO 2 0 119.0 10.6 91 90 224 09/06/05 LotJ 302 2 0 118.7 9.6 91 90 -----· ------------·······--------------·····-····-··--·---····· 225 09/07 /05 Lot 3 304 2 0 120.2 9.3 92 90 226 09/07/05 Lot 3 305 2 0 118.2 8.8 91 90 227 09/07/05 Lot 3 306 2 0 117.0 9.2 90 90 228 09/07105 Lot 3 318 2 0 122.8 9.5 94 90 229 09/07/05 Lot 3; Nonh 319 2 0 121.7 7.8 94 90 ··--········· ---------------------------········ .. ···--·· ·······--- 230 09!07 /05 Lot 3 307 2 0 117.9 8.0 91 90 231 09/07/05 Lot 3 310 2 0 118.8 12.6 91 90 232 09/07 /05 Lot 3 319 2 0 I 18.9 8.5 91 90 233 09/08/05 Lot 3 308 2 0 119.6 8.8 92 90 234 09/08/05 Lot 3 309 2 0 118.6 9.4 91 90 -------------------····················· 235 09/08/05 Lot 3 313 2 0 122.4 9.2 94 90 236 09/08/05 Lot 3 312 2 0 122.8 8.9 94 90 237 09/08/05 Lot 3 308 2 0 121.7 10.7 94 90 238 09/08105 Lot 3 310 2 0 121.5 8.5 93 90 239 09/09/05 Lot 3 314 2 0 117.7 10.2 . 90 90 ........... . ............... 240 09/09/05 Loi 3 Jll 2 0 122.9 8.0 94 90 241 09/09/0S Lot 3 309 2 0 119.4 8.7 92 90 242 09/13/05 Lot 3 320 2 0 120.1 8.7 92 90 243 09/13/05 Lot 3; North 325 2 0 120.6 9.0 93 90 244 09/13/05 Lot 3; North 322 2 0 117.1 8.4 90 90 ................. ····•••·•••• ................. 245 09/13/05 Loi 3 328 2 0 117.5 8.7 90 90 246 09/14/05 Lot 3; North 331 2 0 119.7 9.2 92 90 247 09/14/05 Lot 3 335 2 0 121.9 8.7 94 90 248 09/14105 Lot 3 337 2 0 118.9 8.9 91 90 249 09/14105 Lot 3; North 338 2 0 117.3 8.0 90 90 ·•····•···••••·•••••••••••••••••• ---....................... 250 09/14105 Lot 3 340 2 0 117.9 8.6 91 90 251 09/15/05 Lot 6 352 2 0 117.2 ILO 90 90 252 09/15/05 Lot 6 354 2 0 120.9 10.4 93 90 253 09/15/05 Lot 6 355 2 0 121.9 9.0 94 90 254 09115/05 Lot 6 357 2 0 117.6 9.3 90 90 ................ ......... 255 09116/05 Lot 3 313 2 0 121.4 8.4 93 90 256 09/16/05 Lot 3 318 2 0 119.6 8.9 92 90 257 09/16/05 Loi 3 315 2 0 118.4 9.2 91 90 258 09/16/05 Lot 3 316 2 0 118.8 8.8 91 90 259 09/19/05 Lot 3; North 345 5 0 122.0 8.6 90 90 .. .... 260 09/19/05 Lot 3; North 347 5 0 125.4 8.0 93 90 261 09/19/05 Lot 3; North 348 2 0 119.4 8.5 92 90 262 09/19/05 Lot 3 351 2 0 118.1 9.0 91 90 263 09/19/05 Lot 3: North 352 5 0 121.6 8.1 90 90 ST 264 09/20/05 Lot 3 JOO 5 0 119.2 9.0 88 90 Project No. 06442-32-04A August 30, 2006 TABLE I SUMMARY OF FIELD DENSITY TEST RESULTS Elev. Pl~ Field Field Field Req'd. o, 3/4" Dey Moist Rel. Rel. Depth C=, Rock Dem. Cont. Comp. Comp. Test No. [),re Location (ft) No. (%) (poO (%) (%) (%) ST 264A 09/26/05 Lot 3 300 5 0 122.0 7.5 90 90 265 09/20/05 Lot 3 352 5 0 121.6 8.0 90 90 266 09/20/05 Lot 3; North 354 5 0 123.9 7.8 92 90 267 09/20/05 Lot 3; North 355 5 0 122.4 8.2 91 90 268 09/21/05 Lot 3; North 358 5 0 121.7 7.0 90 90 -------------------------269 09/21/05 Lot 3; North 360 5 0 121.6 7.6 90 90 270 09/21/05 Lot 3; North 364 5 0 124.7 7.5 92 90 271 09/21/05 Lot 3; North 267 5 0 121.6 7.0 90 90 272 09/22'05 Lot 6 340 5 0 121.6 7.9 90 90 273 09/22/05 Lot 6 343 5 0 125.4 8.2 93 90 ··------·---------------- 274 09/22/05 Lot 8 344 2 0 118.0 8.5 91 90 275 09/22/05 Lot 8 346 2 0 117.6 9.0 90 90 276 09/22/05 Lot 6 344 5 0 121.9 7.9 90 90 277 09/22/05 Lot 6 349 5 0 127.l 7.6 94 90 278 09/22/05 Lot 8 346 2 0 ll7.S 9.0 90 90 ------------------ 279 09/22/05 Lot 8 347 2 0 119.4 8.2 92 90 280 O'.lf23/05 Lot 6 346 5 0 125.4 7.0 93 90 281 09/23/05 Lot 6 349 5 0 123.2 8.2 91 90 282 09/23/05 Lot 8 346 2 0 117.2 9.1 90 90 283 09/23/05 Lot 8 349 2 0 122.0 8.7 94 90 -·-·-· ----· 284 09/23/05 Lot 8 320 2 0 120.6 9.0 93 90 285 09/23/05 Lot 8 325 2 0 117.1 8.5 90 90 286 09/23/0S Lot 6 344 2 0 117.6 9.3 90 90 287 09/23/05 Lot 6 346 2 0 120.2 9.0 92 90 288 09/26/05 Lot 6 360 2 0 114.5 4.5 88 90 ····-·---------------288A 09/26/05 Lot 6 360 2 0 119.7 8.9 92 90 289 09/26/05 Lot 6 359 2 0 113.4 4.9 87 90 289A 09/2{,/()5 Lot 6 359 2 0 117.2 87 90 90 ST 290 09/26/05 Lot 3 305 5 0 122. l 7.5 90 90 ST 291 09/26/05 Lot 3 285 5 0 123.3 8.0 91 90 ---------------------------------------------------· ·······-···--. ST 292 09/26/05 Lot 3 295 5 0 121.6 7.9 90 90 293 09/26/05 Lot 8 340 3 0 116.8 9.0 91 90 294 09/26/05 Lot 8 336 3 0 121.1 8.9 95 90 295 09127 /OS Lot 3 319 5 0 127.3 8.5 94 90 296 09/27 /0S Lot 3 315 5 0 122.9 8.7 90 -----------· --------------· --297 09/27/05 Lot 5 324 5 0 121.6 7.5 90 298 09f27/05 Lot 5 329 5 0 122.0 7.6 90 90 299 09f27/05 Lot 8 350 2 0 119.3 9.4 92 90 300 09'27/05 Lot 8 346 2 0 121.6 8.7 93 90 301 09/28/05 Lot 6 350 2 0 120.7 9.4 93 90 .... -·-··---· --·-·-----------········ ..... 302 09/28/05 Lot 6 353 2 0 117.J 8.5 90 90 303 09/28105 Lot 6 354 2 0 I 18.1 8.9 91 90 304 09/29/05 Lot 6 358 2 0 117.S 8.5 90 90 305 09/29/05 Lot 6 360 2 0 119.3 9.0 92 90 306 09/29/05 Lot 13 355 2 0 117.6 9.2 90 90 Project No. 06442-32-04-A Augwt 30, 2006 TABLE I SUMMARY OF FIELD DENSITY TEST RESULTS Elev. Plus Field Field Field Req'd. °' 3/4" D,y Moist. Rel. Rel. lloplh am,, Rock -· Cont. Comp. Comp. Test No. ""' Location (ft) No. (%) (pcO (%) (%) (%) 307 09/29/05 Lot 8; North 355 2 0 117.1 9.0 90 90 308 09/29/05 Lot 8 328 2 0 122.0 8.4 94 90 309 09129/05 Lot 8 330 2 0 118.5 8.9 91 90 310 09/30/05 Lot 7 367 2 0 I 18.1 8.7 91 90 311 09/30/05 Lot 7 368 2 0 117.3 8.5 90 90 -----··--------·-··········----·········· --------------------·-············-····----·-···· 312 09/30/05 Lot 8; North 375 2 0 122.4 8.3 94 90 313 09/30/05 Lot 8; North 378 2 0 117.2 9.3 90 0 314 09/30/05 Lot 13 380 2 0 119.3 8.5 92 90 315 09/30/05 Lot I 3 375 2 0 117.6 9.1 90 90 316 09/30/05 Lot 13 373 2 0 118.5 8.8 90 317 10/03/05 Lot 8; North 365 2 0 120.0 9.0 90 3(8 10/03/05 Lot 8; North 370 2 0 117.6 8.4 90 90 319 10/03/05 Lot 8; North 375 2 0 Jl7.2 9.5 90 90 320 10/03/05 Lot 8; North 377 2 0 118.8 11.2 91 90 321 1003105 Lot 13 376 2 0 123.3 9.4 95 90 .. ST 322 10/04/05 Lot 3; North 345 5 0 121.7 8.0 90 90 ST 323 10/04/05 Lot 3: North 355 5 0 124.2 7.5 92 90 ST 324 10/04/05 Lot 3; North 355 5 0 121.6 7.0 90 90 ST 325 10/04/05 Lot 3; North 365 5 0 122.2 7.1 90 90 326 10/04/05 Lot 13 380 2 0 118.0 8.4 91 90 327 10/04/05 Lot 8; North 380 2 0 122.3 8.8 94 90 328 10/04/05 Lot 13 383 2 0 119.8 9.4 92 90 329 10/05/05 Lot 8; North 385 2 0 120.7 9.1 93 90 330 I 0/05/05 Lot I 3 383 2 0 117.1 8.4 90 90 331 10/05/05 Lot 8; North 360 2 0 117.9 8.5 9( 90 ................... ------ 332 10/05/05 Whiptail Loop 13+50 305 2 0 113.4 4.0 87 90 332A 10/05/05 Whiptail Loop 13+50 305 2 0 117.1 8.4 90 90 333 10/05/05 Whiptail Loop 11+50 290 2 0 114.7 4.6 88 90 333A 10/05105 Whiptail Loop 11+50 290 2 0 117.4 8.7 90 90 334 ..... 10/06/05_ Whiptail Loop 57+00 ___ 389 2 0 120.7 8.5 93 90 ··-···· ------------------···-·- 335 10/06/05 Whiptail Loop 58+00 381 2 0 117.2 8.7 90 90 336 10/06/05 Lot 13 365 2 0 117.9 8.4 91 90 337 I 0/06J05 Lot 13 370 2 0 117.1 8.6 90 90 338 10/06/05 Loi 8 350 2 0 123.9 9.3 95 90 339 I (V()6105 Lot 8 325 2 0 I 18.l 9.0 91 90 ---· -----------------············· 340 10/07/05 Lot 8; North 352 2 0 123.3 9.1 95 90 341 10/07/05 Lot 8; North 354 2 0 119.8 8.8 92 90 342 I 0/07 /05 Lot 8 330 2 0 117.6 9.0 90 90 343 I 0/07 /OS Lot 8 330 2 0 120.2 8.5 92 90 344 I 0/07 /05 Lot 8 388 2 0 122.4 8.7 94 90 -------·--- 345 10/07/05 Lot 13 364 2 0 117.1 8.1 90 90 346 10/07/05 Lot 13 368 2 0 121.1 8.4 93 90 347 10/07/05 Lot 8; North 370 2 0 117.6 8.8 90 90 348 10/07/05 Lot 8 330 2 0 118.4 8.7 91 90 349 10/10/05 Lot 8; North 368 2 0 117.2 8.6 90 90 Project No. 06442-32-04A August 30, 2006 TABLE I SUMMARY OF FIELD DENSITY TEST RESULTS Elev. Plus Field Field Field Req'd. o, 3/4" Dcy Moist. Rel. Rel. Depth Curve Rock Dens. Cont. Comp. Comp. Test No. Dato Location (ft) No. (%) (pc0 (%) (%) (%) 350 10/10/05 Lot 13 370 2 0 122.7 9.2 94 90 351 10/10/05 Lot 8; North 372 2 0 117.5 8.2 90 90 352 10/10/05 Lot 8 334 2 0 qo.o 8.5 92 90 353 10/10/05 Lot 8 338 2 0 117.5 8.4 90 90 354 10/10/05 Lot 8 336 2 0 121.8 8.9 94 90 355 10/10/05 Lot 8 332 2 0 117.2 9.0 90 90 356 10/11/05 Lot 8; North 385 2 0 120.0 9.0 92 90 357 10/11/05 Lot 8; North 376 2 0 118.l 8.8 91 90 358 10/11/05 Lot 8; North 387 2 0 117.6 8.5 90 90 359 10/11/05 Lot 8 338 2 0 120.7 8.8 93 90 360 10/11/05 Lot 8 333 2 0 IIB.4 8.2 91 90 361 10/12/05 Lot 6 358 2 0 117.i 8.0 90 90 362 10/11105 Lot 6 360 2 0 119.4 8.7 92 90 363 10112/05 Lot 6 362 2 0 123.6 8.5 95 90 364 10/12/05 Lot 4 355 2 0 120.3 8.7 92 90 365 10/11105 Lot 4 362 2 0 117.l 9.0 90 366 10/13/05 Lot 13 393 2 0 118.0 8.4 91 90 367 10/13/05 Lot 13 385 2 0 117.5 8.2 90 90 368 10/13/05 Lot 13 395 2 0 118.4 8.6 91 90 369 10/13/05 Lot 7 360 2 0 120.7 9.0 93 90 . . . "' -.. -·--·-· ·-----·-----· -------.. ----········ ..................... 370 10/14/05 Lot 13 396 2 0 119.9 8.5 92 90 371 10/14/05 Lot 13 380 2 0 123.7 9.3 95 90 372 10/14105 Lot 8; North 375 2 0 117.2 9.0 90 90 373 10/14/05 Lot 7 363 2 0 120.7 8.9 93 90 374 10/17/05 Lot 8 329 2 0 117.5 9.0 90 90 ............... 375 10/17/05 Lot 8 332 2 0 117.6 9.2 90 90 376 10/17/05 Lot 8; North 390 2 0 123.9 8.7 95 90 377 10/17/0S Lot 8 380 2 0 120.7 8.8 93 90 378 10/18/05 Lot 8 335 2 0 120.6 8.9 93 90 379 l~J-~-~--~~J?C B~-~!~_Lots 6/7 366 2 0 118.0 9.4 91 90 ····---------. ---. . ------------.. -. . . . . . . ........ -... -- 380 10/18/05 Slope Between Lots 6/7 382 2 0 123.1 8.9 95 90 381 10/18/05 Lot 8 344 2 0 121.8 9.6 94 90 382 10/18/05 Lot 8 345 2 0 117.l 10.4 90 90 383 10/18/05 Lot 8 340 2 0 117.5 9.9 90 90 384 10/18/05 Lot 7 375 2 0 120.0 10.2 92 90 385 10/21/05 Lot 8 343 2 0 128.6 4.7 99 90 385 A 10/21/05 Lot8 343 2 0 127.2 11.1 98 90 386 10/21/05 Lot 8 345 2 0 127.4 3.8 98 90 386A 10/21/05 Lot 8 345 2 0 125.7 12.4 97 90 387 10/21/05 Lot 8 345 2 0 122.9 6.9 94 90 387 A I 0/21/05 Lot 8 345 2 0 ll9.2 11.2 92 90 388 I 0/21/05 Lot 9 243 4 0 113.2 16.2 91 90 389 10/21/05 Lot 9 246 4 0 115.2 15.4 93 90 390 10/24/05 Lot 9 238 4 0 112.2 17.9 91 90 391 10/24/05 Lot 9 240 4 0 114.7 18.2 93 90 Project No. 06442-32-04A August 30, 2006 TABLE I SUMMARY OF FIELD DENSITY TEST RESULTS Elev. Pl~ Field Field Field Req'd. o, 3/4" Dry Moist. Rel. Rel. Depth CuNe Rock ""''· Cont. Comp. Comp. Test No. o.~ Location (fi) No. (%) (pcO (%) (%) (%) 392 I 0/24/05 Lot 9 241 4 0 113.9 18.6 92 90 393 I 005/05 Lot 9 250 4 0 112.9 18.0 91 90 394 10/25/05 Lot 9 250 4 0 114.2 17.4 92 90 395 10/27/05 Loi 9 253 4 0 115.0 16.5 93 90 396 1007/05 Lot 9 255 4 0 112.9 17.2 91 90 -·······-------- ST 397 10/31/05 Lot 6 350 2 0 119.4 6.8 92 90 ST 398 I 0/31/05 Lot 6 350 2 0 119.1 6.7 92 90 ST 399 I 0/31/05 Lot 6 350 2 0 119.8 6.7 92 90 ST 400 I 0/31/05 Lot 6 345 2 0 119.5 6.9 92 90 ST 401 10/31/05 Lot6 345 2 120.4 7.0 93 90 ......... ST 402 l 0/31/05 Lot 6 350 2 121.8 5.6 94 90 ST 403 I 001/05 Lot 6 345 2 0 120.3 8.4 92 90 ST 404 10/31/05 Lot 6 345 2 0 117.6 7.9 90 90 ST 405 10/31/05 Lot 6 350 2 0 118.0 8.7 91 90 ST 406 1001/05 Lot6 355 2 0 117.0 8.5 90 90 ST 407 10/31/05 Lot5 325 2 0 116.6 7.1 90 90 ST 408 t0/31/05 Lots 325 2 0 ll7.5 7.3 90 90 FG 409 10/31/05 Lot 3 317 2 0 120.3 7.4 92 90 FG 4IO I 0/31/05 Lot 3 317 2 0 121.1 6.8 93 90 FG 411 10/31/05 Lot 3 320 2 0 120.1 7.2 92 90 -----------.. FG 412 10/31/05 Lot 3 324 2 0 120.3 8.0 92 90 413 11/03/05 Lot 2 257 9 0 104.8 18.4 93 90 414 11/03/05 Lot 2 257 9 0 101.7 19.0 90 90 415 11/04/0S Lot 8 354 2 0 116.5 8.2 90 90 416 11/04/05 Lot 8 351 2 0 117.2 9.3 90 90 4(7 11/04/05 Lot 8; North 394 2 0 119.7 8.7 92 90 418 11/04/05 Lot 8: North 397 2 0 118.7 77 91 90 ST 419 11/14/05 Lot 13; East 390 3 0 117.2 7.1 92 90 ST 420 11/14/05 Lot 13; East 392 3 0 115.5 7.5 90 90 ST 421 11/14/05 Lot 8; North 386 2 0 118.7 8.1 91 90 ···········•··•·•······ ••• ·---············-·--··-------·········· ST 422 11/14/05 Lot 13; East 395 3 0 ll6.5 7.8 91 90 ST 423 11/14/05 Lot 8: North 387 3 0 115.0 7.5 90 90 ST 424 11/14/05 Lot 13; East 395 3 0 115.1 7.8 90 90 ST 425 11/14/05 Lot 8; North 386 3 0 115.9 7.4 91 90 426 11/15/05 Lot 8 348 9 0 104.0 18.5 92 90 ····-··-------------······ ••••••••••••••••••••••• ----· ....... ..... 427 11/15/05 Lot 8 346 9 0 101.7 20.2 90 90 428 11/15/05 Lot 8 350 9 0 102.1 22.1 90 90 429 l l/16/05 l..ot 8 349 9 0 104.8 19.4 93 90 430 11/16/05 l..ot 8 348 9 0 l03.0 20.1 91 90 431 11/17/05 Lot 7 383 3 0 ll5.0 8.6 90 90 ----- 432 ll/17/05 Lot7 389 2 0 122.9 8.6 94 90 433 I 1/18/05 Lot 7 386 2 0 123.5 8.8 95 90 434 11/18/05 Lot 7 389 2 0 I 19.9 8.1 92 90 435 11/21/05 l..ot 2 256 13 0 113.2 14.1 93 90 436 11121/05 l..ot 2 258 13 0 111.0 12.7 91 90 Project No. 06442-32--04A August 30, 2006 TABLE I SUMMARY OF FIELD DENSITY TEST RESULTS Elev. Plus Field Field Field Req'd. o, 3/4" Thy Moist. Rel. Rel. Dopth C""" Rock °""'· Cont. Comp. Comp. Test No. Date Location (ft) No. (%) (pd) (%) (%) (%) 570A 03/16/06 Lot 1 252 19 0 105.6 14.9 90 90 571 03/27/06 Lot 2 258 13 0 110.7 13.3 91 90 572 03/27/06 Lot 2 262 13 0 113.2 12.7 93 90 573 03/28/06 Lot l 253 12 0 116.l I 1.8 90 90 574 03/28/06 Lot 1 254 12 0 121.5 12.7 94 90 515 03/28/06 Lot I 255 12 0 119.5 10.l 93 90 576 04/03/06 Lot 1 255 19 0 105.7 16.9 90 90 577 04/03/06 Lot I 258 19 0 106.5 15.9 91 90 578 04/11/06 Lot I 252 19 0 108.6 16.8 93 90 579 04/11/06 Lot 1 252 0 l05.7 17.4 90 90 ST 580 04/14/06 Lot 2; Stability Fill 285 0 115.2 10.8 92 90 ST 581 04/14/06 Lot 2; Stability Fill 285 21 0 112.8 12.3 90 90 ST 582 04/20/06 lDt 2; Stability Fill 292 19 0 107.9 14.9 92 90 ST 583 04f20/06 Lot 2; Stability Fill 283 19 0 111.0 14.6 95 90 ST 584 04/20/06_ Lot 2; Stability Fill 285 19 106.5 14.7 91 90 ------············--············· ST 585 04/20/06 Lot 2; Stability Fill 285 19 l05.4 14.5 90 90 586 04/21/06 Lot 9 256 16 0 107.8 15.6 90 90 587 04/21/06 Lot 9 259 16 0 109.8 16.0 92 90 FG 588 04/26/06 Lot 9 258 13 0 110.8 12.7 91 90 FG 589 04/26/06 Lot 9 260 0 110.3 13.1 90 90 FG 590 04/26/06 Lot 9 262 0 109.9 13.5 90 90 ST 591 04/26106 Lot 9 253 13 0 109.8 15.5 90 90 ST 592 04/26/06 Lot 9 250 13 0 111.0 14.8 91 90 593 04/28/06 Lot 6 364 22 0 113.5 16.5 93 90 594 04/28/06 Lot 6 363 22 0 109.8 15.4 90 90 ---------··················-- 595 05/03/06 Lot 6 360 22 0 116.2 11.8 95 90 596 05/03/06 Lot 6 360 22 0 113.1 12.7 93 90 597 06/13/06 Lot 6 357 32 0 119.5 4.5 89 90 597 A 06/13/06 Lot 6 357 32 0 122.2 7.0 91 90 598 06/13/06 Lot 6 357 32 0 118.8 5.5 89 90 598 A 06/13/06 Lot 6 357 32 0 120.6 7.2 90 90 Project No. 06442-32-04A August 30, 2006 TABLEI EXPLANATION OF CODED TERMS -TEST SUFFIX A, B, C, ... : Retest of previous density test failure, following moisture conditioning and/or recompaction. -SFRIKB-OUT Fill in area of density test failure was removed and replaced with properly compacted fill soil. -PREFIX CODE DESIGNA TJON FOR TEST NUMBERS DTN -DUPLICATE TEST NUMBER PG -FINISH GRADE ST -SLOPE TEST -CURVE NO. Corresponds to curve numbers listed in the summary of laboratory maximum dry density and optimum moisture content test results table for selected fill soil samples encountered during testing and observation. -ROCK CORRECTION For density tests with rock percentage greater than zero, laboratory maximum dry density and optimum moisture content were adjusted for rock content. For tests with rock content equal to zero, laboratory maximum dry density and optimum moisture content values are unadjusted. -TYPE OF TEST SC: Sand Cone Test (ASTM D 1556) NU: Nuclear Density Test (ASTM D2922) OT: Other -ELEV A TI ON/DEPTH Test elevations/depths have been rounded to the nearest whole foot. Project No. 06442-32-04A August 30, 2006 Proctor Curve No, l 2 3 4 5 9 12 13 14 15 16 18 19 20 21 22 24 32 TABLE II SUMMARY OF LABORATORY MAXIMUM DRY DENSITY AND OPTIMUM MOISTURE CONTENT TEST RESULTS ASTM D 1557-02 Maximum Optimum Source and Description Dry Density Moisture Content (pcf) (%) Dark brown, Silty, fine SAND 129.2 8.5 Olive brown, Silty, fine to coarse SAND with trace gravel 130.l 8.6 Very dark brown, Clayey, fine to coarse 128.0 8.9 SAND with trace gravel Very dark brown, Clayey, fine to medium 123.9 12.0 SAND, with trace gravel Dark reddish brown, Clayey. fine to coarse 135.l 7.4 SAND with trace gravel Light olive, fine to medium, Sandy SU...T 112.9 17.3 with little clay Olive gray, Silty, fine to medium SAND 128.9 9.2 Light yellowish brown, Silty, fine to coarse 122.0 11.8 SAND with silt Light yellowish brown, Silty CLA YI 107.5 17.8 Clayey SILT Olive green, Silty CLAY 112.2 17.8 Light yel1owish brown, Clayey, fine to 119.4 12.6 coarse SAND Light brown, fine, Sandy SILT 115.5 15.0 Dark brown, Clayey, fine to coarse SAND 117.0 14.7 with trace gravel Very dark reddish brown, Silty, fine to 133.1 7.6 medium SAND Light brown, fine to coarse, Clayey, SAND 124.9 11.4 with trace gravel Brown, Clayey, fine to medium SAND 122.0 11.4 Olive brown, Clayey, fine to coarse SAND with trace silt 124.0 11.3 Dark yellowish brown, Silty, fine to coarse 134.0 7.3 SAND with trace gravel and clay Project No. 06442-32-04A August 30, 2006 TABLE Ill SUMMARY OF LABORATORY EXPANSION INDEX TEST RESULTS ASTM D 4829-03 Sample No. Moisture Content Dry Density Expansion (Lot No.) Before Test ( % ) After Test(%) (pcf) Index EI-I (Lot 8) 7.7 13.9 118.8 0 EI-2 (Lot 8) 9.1 13.7 113.2 0 El-3 (Lot 8) 8.1 14.9 118.4 0 El-4 (Lot 8) 8.2 13.5 118.2 0 El-5 (Lot 5) 8.9 14.8 113.2 0 EI-6 (Lot5) 8.8 14.7 113.2 0 El-7 (Lot5) 8.8 14. I 113.2 0 El-8 (Lot 7) 8.5 15.6 117.9 0 EI-9 (Lot 7) 8.9 14.2 113.0 0 EI-IO (Lot 7) 8.2 13.1 117.9 0 El-JI (Lot4) 8.3 14.3 117.8 0 El-12(Lot4) 8.4 13.9 113.8 0 El-13(Lot4) 8.4 15.8 117.6 2 El-14(Lot3) 9.0 16.5 113.0 I El-15 (Lot3) 9.3 14.9 113.9 2 El-16 (Lot 3) 8.4 14.2 117.8 I TABLE IV SUMMARY OF LABORATORY DIRECT SHEAR TEST RESULTS ASTM D 3080-03 Sample Dry Density Moisture Content Unit Cohesion Angle of Shear No. (pcf) (%) (pd) Resistance (degrees) 5 121.5 7.4 l015 48 9 102.6 17.1 250 18 12 116.2 9.1 220 30 13 111.3 11.9 440 39 14 99.3 16.3 230 34 15 100.3 18.5 400 19 16 108.3 12.7 360 33 Project No. 06442-32-04A August 30, 2006 GEOCON GEOTECHNICAL CONSULTAN 0 INCOHPQI\ATF.D Project No. 06442-32-04A October 30, 2008 Techbilt Construction Company 3575 Kenyon Street San Diego, California 92110 Attention: Subject: Mr. Raul Guzman CARLSBAD OAKS NORTH BUSINESS PARK-PHASE I LOT 1 CARLSBAD, CALIFORNIA ADDENDUM TO FINAL REPORT OF TESTING AND OBSERVATJON SERVJCES DURING SJTE GRADING Reference: 1. Addendum to Final Report of Testing and Observation Services During Site Grading, Carlsbad Oaks North Business Park-Phase], Lots 2 and 6, Carlsbad, Cal[fornia, prepared by Geocon Incorporated, dated December 26, 2007 (Project No. 06442-32-04A). 2. Final Report of Tesling and Observation Services During Site Grading, Carlsbad Oaks North Business Park -Phase 1, lots 1 through 9, Carlsbad, California, prepared by Geocon Incorporated, dated August 30, 2006 (Project No. 06442- 32-04A). 3. Grading and Erosion Control Plansj0r: Carlsbad Oaks North, Phase 1, Drawing No. 415-9A, C.T. 97-13, prepared by O'Day Consultants, with City of Carlsbad signature dated October 26, 2004. Dear Mr. Guzman: We have prepared this addendum to Reference No. 2 to present information collected during minor grading operations performed on the subject lot subsequent to issuance of the geotcchnical report. The additional grading was performed in July 2008. The scope of our services included the following: • Observing the grading operation. • Performing in-place density and moisture content testing in fill placed and compacted on the subject lot. • Performing laboratory testing to aid in evaluating the maximum dry density, optimum moisture content of the compacted fill. Additionally, laboratory testing was performed on samples of soil present at finish grade to evaluate the expansion characteristics and water- soluble sulfate content. 6960 Flanders Drive ■ Son Diego, Colifo,nio 92121-2974 ■ Telephone (858) 558-6900 ■ fax (858) 558-0159 • Revising the As-Graded Geologic Map presented in our report dated August 30, 2006, to reflect the new as-graded conditions. • Preparing this addendum report of grading. GRADING As discussed in our report dated August 30, 2006, the initial grading on Lot 1 consisted of removing surficial deposits to expose dense Point Loma Formation. Fills were then placed and compacted within the lot. Where very dense formation soils were exposed at pad sheet-grade, the formation was undercut approximately 5 feet below the design grades presented on the project grading plans (Reference No. 3) and partially replaced with compacted fill. Grading resulted with slope areas and the outer approximately 15 feet of the building pad constructed to design grades. In general, the central portion of the pad was left approximately 2 feet to 4 feet below design sheet-grade upon completion of Phase I mass grading. Recent grading consisted of placing and compacting a soil stockpile located in the central portion of the pad. These soils were generated from other areas of the business park and from off-site. Fills were placed in lifts no thicker than would allow for adequate bonding and compaction. The soil was moisture conditioned, as necessary, and mixed during placement. Fills generally consisted of silty to clayey sand to silty sand. The finish elevation contours presented on Figure 1 were provided by the project civil engineer, O'Day Consultants, and reflect actual pad grade after completion of grading. For the following testing references, we utilized the app1icable ASTM or California version of the test procedure at the time of testing. During the grading operation, we observed compaction procedures and performed in-place density testing to evaluate the relative compaction of the fill soils. We performed in-place density testing in general conformance with ASTM D 2922. Results of the in-place dry density and moisture content tests pertinent to Lot 1 are swnmarized on Table I. Lot 1 was initially graded concurrently with the overall Phase 1 mass grading operations for the Carlsbad Oaks North Business Park. Test results for areas beyond Lot 1 are excluded from Table I. Consequently, test number designations are not consecutive. In-place density test results taken during previous and recent grading indicate fill soils have a dry density of at least 90 percent of the laboratory maximum dry density near to slightly above the optimum moisture content at the locations tested. We have revised Figure I of Reference No. 2 to include the approximate locations of recent in-place density testing perfonned on the lot. We perfonned laboratory testing on samples of soil used for fill to evaluate moisture-density relationships, optimum moisture content and maximum dry density (ASTM D 1557). We also performed laboratory testing on samples collected at finish grade to evaluate their expansion potential Project No. 06442-32-04A -2-October 30, 2008 (ASTM D 4829) and water•soluble sulfate content (California Test No. 417). Results of the laboratory tests are summarized on Tables II through IV. Finish Grade Soll Conditions Observations and laboratory test results indicate that randomly sampled soils at finish grade of Lot 1 have an Expansion Index (El) ranging from 46 (low expansive) to 76 (medium expansive). Table I presents soil classifications based on ASTM D 4829. Results of the finish grade EI tests are summarized on Table ill. TABLE 1 SOIL CLASSIFICATION BASED ON EXPANSION INDEX ASTMD4829 Expansion Index (El) Soil Classification 0-20 Very Low 21-50 Low 51-90 Medium 91 -130 High Greater Than 130 Very High The building pad of Lot 1 was generally graded to approximately l• to 3•feet below design pad grade shown in Reference No. 3. Figure 1 reflects the as•graded lot configuration. In general and with respect to design pad grades shown on the project grading plans (Reference No. 3), the upper 10 feet of the pad was graded with soil fill containing rock fragments less than 12 inches in maximum dimension and 6 inches in the upper 3 feet. Rock material greater than 12 inches was placed deeper than 10 feet below the original proposed finish grade. Where an undercut was performed on the pad portion of the lot, the undercut was extended at least 5 feet below the original design sheet grade and replaced with properly compacted filL The areas that have been undercut are annotated as Que on the As-Graded Geologic Map. Corrosive Potential Samples obtained for expansion testing were also subjected to water-soluble sulfate testing to assess whether the soil contains high enough sulfate concentrations that could damage normal Portland cement concrete. Table IV summarizes the sulfate test results. In accordance with 2007 California Building Code (CBC), we have classified sulfate test results using guidelines presented in the American Concrete Institute (ACI) 318-08, Building Code Requirements for Structural Concrete and Commentary. The laOOratory test results indicate an exposure class S 1 and SZ with severity medium Project No. 06442-32-04-A October 30, 2008 to severe based on Table 4.2.1 of ACI 318--08. ACI guidelines (see Table 4.3.1, ACI 318-08) should be followed in determining the type of concrete to be used. The presence of water-soluble sulfates is not a visually discernible characteristic; therefore, other soil samples from the site could yield different sulfate concentrations. Over time, landscaping activities (i.e., addition of fertilizers and other soil nutrients) may also increase the concentration. Geocon Incorporated does not practice in the field of corrosion engineering. If improvements that could be susceptible to corrosion are planned, it is recommended that further evaluation by a corrosion engineer be performed. SOIL AND GEOLOGIC CONDITIONS Grading on Lot 1 has resulted in compacted fill (Qcf and Que) overlying the Point Loma Formation (Kp). A small area of this formation is exposed at grade in the cut slope located along the southwest margin of the lot. The As-Graded Geologic Map (Figure 1) depicts the general geologic conditions observed during grading operations. Geologic contacts should be considered approximate. CONCLUSIONS 1.0 General 1.1 Based on observations and test results, it is the opinion of Geocon Incorporated that the grading, which is the subject of this report, has been performed in substantial conformance with the recommendations of the referenced geotechnical reports. Soil and geologic conditions encountered during grading that differ from those anticipated by the geotechnical report are not uncommon. Where such conditions required a significant modification to the recommendations of the geotechnical report, they have been described herein. 1.2 No soil or geologic conditions were observed during grading that would preclude the continued development of Lot 1. Based upon laboratory test results and field observations, it is our opinion that the fill soils within the subject lot have been compacted to at least 90 percent relative compaction at the locations tested. 1.3 Fine grading and construction of utilities/foundations may encounter very dense formational materials and/or generate some concretionary fragments and/or rock material 12 inches or greater in size. Deeper excavations within the fill (10 feet or greater) for improvements such as utility lines, loading docks, etc., may also encounter oversize material (12 inches or greater). The potential for these conditions should be taken into Project No. 06442-32-04A -4 -October 30, 2008 consideration when detennining the type of equipment to utilize for future excavation operations. The oversize material may require special handling techniques and exportation. 1.4 It is not uncommon for groundwater or seepage conditions to develop where none previously existed, particularly after landscape irrigation is initiated. The occurrence of induced groundwater seepage from landscaping can be greatly reduced by implementing and monitoring a landscape program that limits irrigation to that sufficient to support the vegetative cover without overwatering. Shallow subdrains may be required in the future if seeps occur after rainy periods or after landscaping is installed. 1.5 References to the thickness and extent of undercutting and rock hold-down areas within the building pads are approximate and were based upon the finish-grade elevations of the approved referenced grading plans. 1.6 Geotechnical recommendations presented in Reference No. 2 remain applicable for the continued development of Lot 1. 1. 7 An update geotechnical report presenting fine grading recommendations and geotecbnical design criteria for the ultimate development of the lot should be prepared by Geocon Incorporated once fme grading plans have been prepared. LIMITATIONS The conclusions and recommendations contained herein apply only to our work with respect to grading and represent conditions at the date of our final observation of grading operations on July 2008. Any subsequent grading should be done in conjunction with our observation and testing services. As used herein, the term observation implies only that we observed the progress of the work with which we agreed to be involved. Our services did not include the evaluation or identification of the potential presence of hazardous materials. Our conclusions and opinions as to whether the work essentially complies with the job specifications are based on our observations, experience and test results. Due to the inaccuracies inherent in most field and laboratory soil tests, and the necessary assumption that the relatively small soil sample tested is representative of a significantly larger volume of soil, future tests of the same soil location or condition should not be expected to duplicate specific individual test results of this report. Subsurface conditions, and the accuracy of tests used to measure such conditions, can vary greatly at any time. We make no warranty, express or implied, except that our services were performed in accordance with engineering principles generally accepted at this time and location. Project No. 06442-32-04-A October 30. 2008 TABLE I SUMMARY OF FIELD DENSITY TEST RESULTS Elev. Plus Field Field Field Req'd. o, 3/4" Dey Moist. Rel. Rel. Depth Curve Rock Dens. Cont. Comp. Comp. Test No. D>l< Location (ft) No. (%) (poO (%) (%) (%) 8 07/14/05 Lot I 230 0 II6.3 9.7 90 90 9 07/14/05 Lot I 232 0 118.5 10.1 92 90 IO 07/14/05 Lot 1 236 0 117.6 10.0 91 90 II 07/14/05 Lot l 240 0 116.7 9.8 90 90 12 07 /I 5/05 Lot I 238 0 119.1 10.4 92 90 -----------············ --------·····-----····--····--·-·----------13 07/15/05 Lot I 242 I 0 117.1 9.3 91 90 14 07115/05 Lot I 244 0 I 16.3 9.5 90 90 15 07/lS/05 Lot I 245 I 0 116.8 10.7 91 90 19 07 !20/05 Lot I 236 3 0 116.0 9.3 91 90 20 07120/05 Lot I 244 3 0 115.2 9.5 90 90 ...... 21 07/2Q/05 Lot I 246 3 0 118.0 9.6 92 90 57 07/28/05 Lot 1 255 3 0 117.4 9.6 92 90 58 07128/05 Lot l 249 3 0 115.2 9.9 90 90 100 08/10/05 Lot l 255 3 0 115.5 11.3 90 90 IOI 08/10/05 Lot I 259 3 0 117.5 10.2 92 90 12' 08/17/05 Lot 1 245 4 0 112.3 15.5 91 90 126 08/17/05 Lot 1 247 4 0 111.6 16.0 90 90 ST 133 08/18/05 Lot I 250 2 0 119.6 89 92 90 ST 134 08/18/05 Lot I 250 2 0 121.0 9.0 93 90 151 08/23105 Lot I 252 4 0 114.1 12.5 92 90 ---------·-·········-· -------·······-··· ---·····-······· ST 158 08/24JOS Lot 1 243 I 0 117.1 8.2 91 90 ST 159 08124/05 Lot 1 240 I 0 116.3 8.0 90 90 FG 184 08n9/05 Lot I 260 I 0 117.4 7.2 91 90 FG 185 08/29/05 Lot 1 263 0 116.8 7.0 91 90 562 03/02/06 Lot l 255 13 0 109.8 12.5 90 90 563 03/02/06 Lot I 256 13 0 111.3 13.0 91 90 564 03/06.l06 Lot I 250 15 0 l01.3 20. l 90 90 565 03/06106 Lot I 258 15 0 l03.4 22.1 92 90 566 03/06/06 Lot t 252 15 0 103.7 19.8 92 90 567 03/06/06 Lot I 255 15 0 101.9 21.7 91 90 ··········--·-· ········-· 568 03/07/06 Lot I 251 15 0 103.3 22.0 92 90 569 03/16106 Lot 1 255 19 0 103.0 10.4 88 90 569A 03/16106 Lot 1 255 19 0 l05.3 14.8 90 90 570 03/16/06 Lot l 252 19 0 10:l-.3 11.1 89 90 570A 03/16106 Lot I 252 19 0 105.6 14.9 90 90 ...... 573 03128/06 Lot I 253 12 0 116.1 11.8 90 90 574 03/28/06 Lot I 254 12 0 121.5 12.7 94 90 575 03/28/06 Lot I 255 12 0 119.5 10.1 93 90 576 04/03/06 Lot I 255 19 0 105.7 16.9 90 90 577 04/03/06 Lot 1 258 19 0 106.5 15.9 91 90 -----· ... 578 04/11/06 Lot I 252 19 0 108.6 16.8 93 90 579 04/11/06 Lot I 252 19 0 105.7 17.4 90 90 636 07 /23/08 Lot I 257 24 0 112.6 12.8 91 90 637 07123/08 Lot I 260 18 0 105.3 14.5 91 90 FG 638 07/23/08 Lot 1 255 18 0 106.0 14.0 92 90 Project No. 06442-32-04A October 30, 2008 TABLE I EXPLANATION OF COOEO TERMS -TEST SUFFIX A, B, C, ... : Retest of previous density test failure, following moisture conditioning and/or recompaction. -STIHKEOUT Fill in area of density test failure was removed and replaced with properly compacted fill soil. -PREFIX CODE DESIGNATION FOR TEST NUMBERS DTN -DUPLICATE TEST NUMBER FG -FINISH GRADE ST -SLOPE TEST -CURVE NO. Corresponds to curve numbers listed in the summary of laboratory maximum dry density and optimum moisture content test results table for selected fill soil samples encountered during testing and observation. -ROCK CORRECTION For density tests with rock percentage greater than zero, laboratory maximum dry density and optimum moisture content were adjusted for rock content. For tests with rock content equal to zero, laboratory maximum dry density and optimum moisture content values are unadjusted. -TYPE OF TEST SC: Sand Cone Test (ASTM D1556) NU: Nuclear Density Test (ASTM D2922) OT: Other -ELEVATION/DEPTH Test elevations/depths have been rounded to the nearest whole foot. -LOCATION DESCR!Pf!ON (IP): Indicates in-place tests. Where (IP) appears in the location description, the compaction procedures were not observed by a representative ofGeocon. Tests were taken at the surface or in test pits after placement of the fill. The results of these tests are indicative of the relative compaction at the location of the test only and may not be extrapolated to adjacent areas. Geocon has no opinion regarding the relative compaction of fill in adjacent areas. Project No. 06442-32-04-A October 30, 2008 TABLE II SUMMARY OF LABORATORY MAXIMUM DRY DENSITY AND OPTIMUM MOISTURE CONTENT TEST RESULTS ASTM D 1557 Procto, Maximum Curve No. Source and Description Dry Density (pd) 1 Dark brown, Silty, fine SAND 129.2 2 Olive brown, Silty, fine to coarse SAND with trace gravel 130.1 3 Very dark brown, Clayey, fine to coarse SAND with !race gravel 128.0 4 Very dark brown, Clayey, fine tomediwn SAND with trace gravel 123.9 12 Olive gray, Silty, fine to medium SAND 128.9 13 Light yellowish brown, Silty, fine to coarse SAND with silt 122.0 15 Olive green, Silty CLAY 112.2 18 Light brown, fine, Sandy SILT l 15.5 19 Dark brown, Clayey, fine to coarse SAND with trace gravel 117.0 24 Olive brown, Clayey, fine to coarse SAND with trace silt 124.0 TABLE Ill SUMMARY OF LABORATORY EXPANSION INDEX TEST RESULTS ASTMD4829 Sample No. Moisture Content(%) Dry Density (Lot No. 2 and location on Pad) Before Test After Test (pd) EI-39(Southwest Portion) 9.4 20.7 112.7 EI-40 (Northwest Portion) 10.3 24.3 108.6 EI-41 (Northeast Portion) 8.9 20.8 112.8 El-42 (Southeast Portion) 8.9 19.1 114.7 TABLE IV Optimum Moisture Content(%) 8.5 8.6 8.9 12.0 9.2 11.8 17.8 15.0 14.7 11.3 Expansion lodex 50 74 56 46 SUMMARY OF LABORATORY WATER-SOLUBLE SULFATE TEST RESULTS CALIFORNIA TEST NO. 417 Sample No.• % Soluble Sulfate El-39 0.290 EI-40 0.183 EI-41 0.268 El-42 0.216 •see Table m for location on pad. ••Reference: Table 4.2.1, ACI 318-08 report. Project No. 06442-32-04A Sulfate Exposure Class** Exposure Rating S2 Severe (high risk) SJ Moderate (medium risk) S2 Severe (high risk) S2 Severe (high risk) October 30, 2008 GEOCON INCORPORATED GEOTECHNICAL ■ENVIRONMENTAL ■ Project No. 06442-32-29 June 28, 2017 Oakmont Senior Living 9240 Old Redwood Highway, Suite 200 Windsor, California 95492 Attention: Subject: Ms. Hannah Daugherty UPDATE GEOTECHNICAL CORRESPONDENCE CARLSBAD OAKS NORTH LOT 1 CARLSBAD, CALIFORNIA Dear Ms. Daugherty: MATERIALSO In accordance with your request, we have prepared this correspondence provide our opinion regarding the feasibility of creating a senior living facility on Lot 1 of the Carlsbad Oaks North Business Park in Carlsbad, California. For the purpose of this letter, we have reviewed the preliminary development plan entitled Oakmont of Carlsbad. Carlsbad, California, Site Plan, prepared by Landesign Group, dated February 2017, and our reports entitled Report of Testing and Observation Services During Site Grading, Carlsbad Oaks North Business Park, Phase 1, Lots 1 through 9, Carlsbad, California, dated October 30, 2006 and Addendum to Report of Testing and Observation Services During Site Grading, Carlsbad Oaks North Business Park, Phase 1, Lot 1, Carlsbad, California, dated October 30, 2008. Lot 1 of the Carlsbad Oaks North Business Park consists of an easterly sloping sheet graded pad that was created in 2006 during the overall mass grading of Carlsbad Oaks North Phase I. The lot was originally left low and subsequently completed in 2008. The as-graded condition consists of compacted fill underlain by the Point Loma Formation. The center portion of the pad was undercut to eliminate cut-fill transitions that resulted from the mass grading. Fill thicknesses across the pad range from approximately 2 to 20 feet. The surface soils have a "low" to "medium" expansion potential and a "moderate" to "severe" sulfate exposure rating. The referenced plan indicates that development will consist of fine grading the site to support a three- story luxury assisted living facility, a two-story memory care building and a one-story models building, A pool, parking areas and associated infrastructure is also proposed. Although the referenced plan is preliminary, we anticipate that cuts and fills on the order of five feet or less will be necessary to achieve the final building pad configuration. Based on our review, and the information above, it is our opinion that the proposed senior living facility is feasible from a geotechnica\ perspective. A future update geotechnical report considering the ultimate development plan should be prepared once civil grading plans are developed. The report would provide specific geotechnical recommendations pertinent to the design and construction of the project. 6960 Flanders Drive ■ Son Diego, California 92121-2974 ■ Telephone 858,558.6900 ■ Fax 858,558.6159 Should you have any questions regarding this correspondence or desire additional information, please contact the undersigned. Very truly yours, GEOCONINCORPORATED k,av7:;d~Nan0s ~ CEG 1860 DBE:ejc ( 4) Addressee Project No. 06442-32-29 . 2. June 28, 20 I 7 GEOCON INCORPORATED GEOTECHNICAL ■ ENVIRONMENTAL Project No. 06442-32-29 September 25, 2017 Oakmont Senior Living 9240 Old Redwood Highway, Suite 200 Windsor, California 95492 Attention: Ms. Hannah Daugherty • MATERIALSO Subject: TRANSMITTAL OF GEOTECHNICAL INFORMATION CARLSBAD OAKS NORTH -LOT I CARLSBAD, CALIFORNIA References: 1. Final Report of Testing and Observation Services During Site Grading, Carlsbad Oaks North Bu~iness Park, Phase I, Lots J through 9, Carlsbad, California, prepared by Geocon Incorporated, dated August 30, 2006. 2. Addendum to Final Report of Testing and Observation Services During Site Grading, Carlsbad Oaks North Business Park -Phase 1, Lot 1, Carlsbad, Cal[/0rnia, prepared by Gcocon Incorporated, dated October 30, 2008. 3. Update Geotechnical Correspondence, Carlsbad Oaks North Lot 1, Carlsbad, California, prepared by Gcocon Incorporated, dated June 28, 2017 (Project No. 06442-32-29). 4. Preliminary Grading and Drainage Plan, Oakmont of Carlsbad, Lot 1 qf Tract No. 14926, prepared by Alliance Land Planning & Engineering, Inc., dated June 30, 2017. Dear Ms. Daugherty: In accordance with your request, Geocon Incorporated has provided geotechnica\ engineering services on the subject project. Specifically, we have performed two in-situ permeability tests to aid in evaluating the on-site stonn water BMP design. The following information is provided to support storm water BMP design in accordance with the 2016 City of Carlsbad Storm Water Standards. STORM WATER MANAGEMENT INVESTIGATION We understand storm water management devices are being proposed in accordance with the 2016 City of Carlsbad Storm Water Standards. If not properly constructed, there is a potential for distress to improvements and properties located hydrologically down gradient or adjacent to these devices. 6960 Flanders Drive ■ Son Diego, Colifomio 92121-2974 ■ Telephone 858.5S8.6900 ■ Fox 8S8.S58.6159 Factors such as the amount of water to be detained. its residence time, and soil permeability have an important effect on seepage transmission and the potential adverse impacts that may occur if the storm water management features are not properly designed and constrncted. We have not performed a hydrogeologicat study at the site. If infiltration of storm water runoff occurs, downstream properties may be subjected to seeps, springs, slope instability, raised groundwater, movement of foundations and slabs, or other undesirable impacts as a result of water infiltration. Hydrologic Soil Group The United States Department of Agriculture (USDA), Natural Resources Conservation Services, possesses general infonnation regarding the existing soil conditions for areas within the United States. The USDA website also provides the Hydrologic Soil Group. Table 1 presents the descriptions of the hydrologic soil groups. If a soil is assigned to a dual hydrologic group (AID, BID, or C/D), the first letter is for drained areas and the second is for undrained areas. TABLE 1 HYDROLOGIC SOIL GROUP DEFINITIONS Soil Group Soil Group Definition A Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, we!\ drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. 8 Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. C Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. D Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or day layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. The subject sheet-graded pad is underlain by compacted fill placed above the Point Loma formation. After completion of the proposed grading operation:., the property would con:.ist of compacted fill over Pont Loma Fonnation. The compacted fill and formational materials should be classified as Soil Group D. In addition, the USDA website also provides an estimated saturated hydraulic conductivity for the existing soil. Table 2 presents the infonnation from the USDA website. The Hydrologic Soil Group Map presents output from the USDA website showing the limits of the soil units. The USDA information is presented in Appendix B. Project No. 06442-32-29 . 2. September 25, 2017 TABLE 2 USDA WEB SOIL SURVEY -HYDROLOGIC SOIL GROUP Map Unit Approximate Hydrologic kSAT of Most Map Unit Name Symbol Percentage Soil Group Limiting Layer of Property (Inches/ Hour) Cieneba coarse sandy loam CiG2 44 D 1.98 -5.95 Huerhuero loam H,D 56 D 0.00 -0.06 In-Situ Testing We performed two Soil Moisture, Inc. Aardvark Permeameter tests at the locations shown on the attached Site Plan, Figure I. Test P-1 was located in the bottom of an existing basin. Some standing water was observed in a portion of this basin. Test P-2 was hand augered until practical refusal was encountered on the Point Loma Formation contact. The test borings were 4 inches in diameter. The results of the tests provide parameters regarding the saturated hydraulic conductivity and infiltration characteristics of on-site soil and geologic units. Table 3 presents the results of the field saturated hydraulic conductivity/infiltration rates obtained from the Aardvark Permeameter tests. The data sheets are presented in Appendix A. We applied a feasibility factor of safety of 2 to the test results. Soil infiltration rates from in-situ tests can vary significantly from one location to another due to the non-homogeneous characteristics inherent to most soil. TABLE 3 FIELD PERMEAMETER INFILTRATION TEST RESULTS Geologic Test Depth Field-Saturated Field Test No. Hydraulic Conductivity, Infiltration Rate Unit (feet, below grade) k,.1 (inch/hour) (inch/hour) P-1 Qcf 2.4 0.0002 0.0001 P-2 Kp 3.75 0.002 0.001 STORM WATER MANAGEMENT CONCLUSIONS The Site Plan, Figure I, presents the existing property and the locations of the in-situ infiltration test locations. Soil Types Compacted Fill -Compacted fill exists across the property. The proposed storm water BMP's will be founded in compacted fill placed above very dense fonnational materials. The compacted fill is comprised of sandy/clayey silt. The fill has been or will be compacted to a dry density of at least 90 percent of the laboratory maximum dry density. In our experience, compacted fill docs not possess Project No. 06442-32-29 - 3 -Septemher 25, 2017 infiltration rates appropriate for infiltration BMP's, as demonstrated by the in-situ testing. Hazards that occur as a result of fill soil saturation include a potential for hydro-consolidation of the granular fill soils and/or swelling of the expansive soils, long-term fill settlement, differential fill settlement, and lateral movement associated with saturated fill relaxation. The potential for lateral water migration to adversely impact existing or proposed structures, foundations, utilities, and roadways, is high. Therefore, full and partial infiltration should be considered infeasible. Section D.4.2 of the 2016 Storm Water Standards (SWS) provides a discussion regarding fill materials used for infiltration. The SWS states: • For engineered fills, infiltration rates may still be quite uncertain due to layering and heterogeneities introduced as part of construction that cannot be precisely controlled. Due to these uncertainties, full and partial infiltration should be considered geotechnically infeasible and liners and subdrains should be used in areas where infiltration BMP's are founded in compacted fill. • Where possible, infiltration BMPs on fill malerial should be designed such that their infiltrating sw:face extends into native soils. The underlying formation below the compacted fill is expected between 5 to IO feet below proposed finish grades after remedial grading is performed. Full and partial infiltration should be considered geotechnically infeasible within the compacted fill and liners and subdrains should be used. lfthe infiltration BMP's extended below the compacted fill, partial infiltration may be feasible. • Because of the uncertainty of fill parameters as well as potential compaction of the native soils, an infiltration BMP may not be feasible. Therefore, full and partial infiltration should be considered geotechnically infeasible and liners and subdrains should be used in the fill areas. • If the source of fill material is defined and this material is known to be of a granular nature and that the native soils below are permeable and will not be highly compacted, infiltration through compacted fill materials may still be feasible. In this case, a project phasing approach could be used including the following general steps, (I) co!!cct samples from areas expected to be used for fill, (2) remold samples to approximately the proposed degree of compaction and measure the saturated hydraulic conductivity of remolded samples using laboratory methods, (3) if infiltration rates appear adequate for irifiltration, then apply an appropriate factor of safety and use the initial rates for preliminary design, (4) following placement of fill, conduct in-situ testing to refine design infiltration rates and adjust the design as needed. However, based on the discussion above, it is our opinion that infiltrating into compacted fill should be considered geotechnically infeasible and liners and subdrains should be used. Infiltration Rates The results of the unfactored infiltration rates (i.e. field saturated hydraulic conductivity) for Tests P-l and P-2 were 0.0002 inches per hour (iph) and 0.002 iph, respectively. After applying a feasibility factor of safety of 2.0, the infiltration rates obtained for P-1 and P-2 are 0.0001 and 0.001 iph, respectively. The infiltration test results show the on-site soil permeability is variable across the site. A Project No. 06442-32-29 September 25, 2017 single design rate for an area could not be accurate based on the variability. Therefore, based on the results of the field infiltration tests, anticipated grading, and our experience, full and partial infiltration should be considered infeasible. The results of the penneability testing are presented in Appendix A. Groundwater Elevations Groundwater is expected to be encountered at depths greater than 100 feet below the site, therefore groundwater is not expected to be a factor. Groundwater mounding is caused when infiltration is allowed and the lateral hydraulic conductivity is relatively low causing an increase in the groundwater table. Groundwater mounding is not likely. Soil or Groundwater Contamination Based on review of the Geotracker website, no active cleanup sites exist on or adjacent to the subject site. In addition, we are not aware of any contaminated soils or shallow groundwater on the site that would preclude storm water infiltration. An environmental assessment was not part of our scope of work. Slopes Existing slopes exist on the perimeter of the property. Infiltration of storm water adjacent to cut or fill slopes should be avoided. Fill slopes will exhibit instability if water is allowed to saturate the compacted fill. Cut slopes may exhibit daylight seepage. Storm Water Management Devices Based on the discussion above, both infiltration tests did not meet the minimum feasibility criteria for full or partial infiltration. To limit the adverse impacts of storm water infiltration, i.e. lateral water migration, daylight water seepage, etc., the design should include liners and subdrains. The impenneable liners should consist of a high-density polyethylene, HOPE, with a thickness of about 30 mil or equivalent Polyvinyl Chloride, PVC. The liner should surround the bottom and sides of the infiltrating surface and should extend slightly above the high water elevation. The subdrain should be perforated, installed near the base of the excavation, be at least 4-inches in diameter and consist of Schedule 40 PVC pipe. The final segment of the subdrain outside the limits of the stonn water BMP should consist of solid pipe and connected to a proper outlet. Any penetration of the liner should be properly waterproofed. The devices should also be installed in accordance with the manufacturer's recommendations. Project No. 06442-32-29 -5 -September 25, 2017 Storm Water Standard Worksheets The Storm Water Standard manual stipulates the geotcchnica! engineer complete the Categorization of Infiltration Feasibility Condition (Worksheet C.4-1 or Form I-8) worksheet information to help evaluate the potential for infiltration on the property. A completed Form I-8 is presented in Appendix 8. The regional storm water standards also have a worksheet (Worksheet D.5-1 or Form I-9) that helps the project civil engineer estimate the factor of safety based on several factors. Table 4 describes the suitability assessment input parameters related to the geotechnical engineering aspects for the factor of safety determination. TABLE4 SUITABILITY ASSESSMENT RELATED CONSIDERATIONS FOR INFILTRATION FACILITY SAFETY FACTORS Consideration High Medium Low Concern -3 Points Concern -2 Points Concern -I Point Use of soil survey maps or Use of well permeameter or borehole methods with simple texture analysis to accompanying Direct measurement with estimate short-term localized (i.e. small- infiltration rates. Use of continuous boring log. scale) infiltration testing Direct measurement of Assessment Methods well penneameter or infiltration area with methods at relatively high borehole methods without localized infiltration resolution or use of accompanying continuous measurement methods extensive test pit boring log. Relatively (e.g., infiltrometer). infiltration measurement sparse testing with direct Moderate spatial methods. infiltration methods resolution Predominant Soil Silty and clayey soils Loamy soils Granular to slightly Texture with significant fines loamy soils Highly variable soils Soil boring/test pits Soil boring/test pits Site Soil Variability indicated from site indicate moderately indicate relatively assessment or unknown variability homogenous soils homogenous soils Depth to Groundwater/ <5 feet below 5-15 feet below > 15 feet below Impervious Layer facility bottom facility bottom facility bottom Based on our geotechnical investigation and the previous table, Table 5 presents the estimated factor values for the evaluation of the factor of safety. This table only presents the suitability assessment safety factor (Part A) of the worksheet. The project civil engineer should evaluate the safety factor for design (Part B) and use the combined safety factor for the design infiltration rate. Project No. 06442-32-29 . 6. September 25, 2017 APPENDIX A AARDVARK TEST RESULTS FOR CARLSBAD OAKS NORTH -LOT 1 CARLSBAD, CALIFORNIA PROJECT NO. 06442-32-29 OGEOCON Aardvark Permeameter Data Analysis Project Name: ____ o_a_k_m_o_n_t_S_en_i_o_r _Li_v_i n..::g:...._ __ Project Number: _____ 0_6_44_2_-3_2_-_29 ____ _ Date: __ 9~/1_5~/2_0_1_7 __ By: ____ D_G __ _ Test Number: P-1 --------------Bore ho 1 e Diameter, d (in.) Borehole Depth, H (in) : 4.00 29.00 Ref. EL (feet, MSL): _ __;2;;;.;3:;..;:8c.;..;.0;:___ Bottom El (feet, MSL): __ ..::2::.3::.5-:.::6:....__ Distance Between Reservoir & Top of Borehole (in.] Estimated Depth to Water Table, S (feet) Height APM Raised from Bottom (in.) Pressure Reducer Used Time Elapsed Reading (min) 1 0.00 2 15.00 3 20.00 4 15.00 5 15.00 6 5.00 7 5.00 8 5.00 ,9 5.00 : : : 28.00 100.00 2.00 No Distance Between Resevoir and APM Float, D (in.): 47.75 Head Height Calculated, h (in.): 5.66 Head Height Measured, h (in.): 57.00 Distance Between Constant Head and Water Table, L (in.): 1228.00 Water Weight Water Volume Q(in3/min) Consummed (lbs) Consumed (in3) 0.000 0.00 0.00 0.060 1.66 0.111 0.025 0.69 0.035 0.010 0.28 0.018 0.015 0.42 0.028 0.005 0.14 0.028 0.005 0.14 O.D28 0.000 o.oo 0.000 0.005 0.14 O.D28 St eady Flow Rate, Q (in3 /min): 0.028 0.03 c .E 0.02 ;;;-- ~ 0.01 C1 0.00 l I FtJz4 I 0 10 20 30 Time (min) 40 50 60 Soil Matric Flux Potential, ¢ 00 cl> m= 0.00004 ! in1/min Field-Saturated Hydraulic Conductivity (Infiltration Ratel K sot = I 4.07E-06 I in/min I 0.0002 OGEOCON Aardvark Permeameter Data Analysis c ·e ;;;-- :S Ci Project Name: ____ o_a_k_m_o_n_t_S_e_n_io_r_L_iv_in...:g;.._ __ Project Number: _____ 0_6_4_4_2_-3_2_-_2_9 ____ _ Date: _ ___,9/_1....:5/_2_01_7 __ By: __ .,,_;D;...G;;._ __ Test Number: P-2 --------------Ref. EL (feet, MSL): __ .::.;25;:.;3:..;,.0,;;__ __ Bottom EL (feet, MSL): ___ 24_9_._3 __ Borehole Diameter, d (In.): 4.00 Borehole Depth, H (in):---4-5.-0-0--~ Distance Between Reservoir & Top of Borehole (in.) 1--_ _.::;28.;;;.·;.;:;0..;;.0 __ _. Estimated Depth to Water Table, s (feet): 100.00 1--------H e I g ht APM Raised from Bottom (ln.):f--__ 2_.0_0 __ _ Pressure Reducer Used: No Distance Between Resevoir and APM Float, D (in.): 63.75 Head Height Calculated, h (in.): 5.71 Head Height Measured, h (in.}: 73.00 Distance Between Constant Head and Water Table, L (in.): 1228.00 Time Elapsed Water Weight Water Volume Q(in3/min) Reading (min) Consummed (lbs) Consumed (in3) 1 0.00 0.000 o.oo 0.00 2 10.00 0.110 3.05 0.305 3 10.00 0.160 4.43 0.443 4 15.00 0.180 4.98 0.332 5 5.00 O.D25 0.69 0.138 6 5.00 0.035 0.97 0.194 7 5.00 0.030 0.83 0.166 8 5.00 0.040 1.11 0.222 9 5.00 0.040 1.11 0.222 10 5.00 0.040 1.11 0.222 11 5.00 0.050 1.38 0.277 12 5.00 0.050 1.38 0.277 Steady Flow Rate, Q (in3 /min): 0.277 0.6 0.1 td+tl -I Id I 0 10 20 30 40 so 60 70 80 Time (min) Soil Matric Flux Potential, <Pm <Pm= 0.0003 !in2/min Field-Saturated Hydraulic Conductivity (Infiltration Ratel K ,., = I 2.72E-0S lin/min I 0.002 APPENDIXB FORM 1-8 FOR CARLSBAD OAKS NORTH -LOT 1 CARLSBAD, CALIFORNIA PROJECT NO. 06442-32-29 Calcgorization of Infiltration Feasibility Condition Fonn 1-8 Part 1 -Full Infiltration Feasibility Screening Criteria Would infiltration of the full design volume be feasible from a physical perspective without any undesirable consequences that cannot be reasonably mitigated? Criteria Screening Question Yes No Is the estimated reliable infiltration rate bdow proposed facility locations greater than 1 0.5 inches per hour? The response to this Screening Question shall be based on a X comprehensive evaluation of the factors presented in Appendix C.2 and Appendix 0. Provide basis: Based on the results of permeability testing in two locations at the site, the unfactored infiltration rates were measured to be 0.0002 inches/hour (iph), and 0.002 iph using a constant head borehole permeameter placed inside a 4-inch diameter boring between 2 and 4 feet below existing grades. If applying a feasibility factor of safety of 2.0, the infi ltration rates would be 0.0001 iph and 0.00 I iph. Based on the USDA Web Soil Survey website, the underlying soils are classified as Cieneba sandy loam and Huerhuero loam and belong to Hydrologic Soil Group D, which are generally not considered suitable for infiltration BMP's. The existing compacted fill should be classified as Hydrologic Soil Group D, which is not suitable for infiltration BMP's. Information collected from the USDA website is attached. The Aardvark Permeameter test results are presented in Appendix A. In accordance with the Riverside County storm water procedures, which reference the United States Bureau of Reclamation Well Permeameter Method (USBR 7300), the saturated hydraulic conductivity is equal to the unfactored infiltration rate. Swnmarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study /data source applicability. 2 Can infiltration greater than 0.5 inches per hour be allowed without increasing risk of geotechnical hazards (slope stability, groundwater mounding, utilities, or other factors) that cannot be mitigated to an acceptable level? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2. X Provide basis: Natural slopes and fill slopes surround the property. Full infiltration adjacent to descending slopes is not recommended due to slope instability and daylight water seepage issues. The landslide potential is very low to negligible. Groundwater mounding is not likely to occur. Existing and proposed utilities would be in close proximity to the proposed BMP's. The potential for lateral water migration and distress to the public and private roadway improvements and proposed buildings is high. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability. Form l-8 Pag,: '.!.of-I Criteria Screening Question 3 Can infiltration greater than 0.5 inches per hour be allowed without increasing risk of groundwater contamination (shallow water table, storm water pollutants or other factors) that cannot be mitigated to an acceptable level? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented m .Appendi.'<. C.3. Provide basis: Groundwater is not located within 10 feet from the proposed infiltration BMP. Yes No X Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability. 4 Can infiltration greater than 0.5 inches per hour be allowed without causing potential water balance issues such as change of seasonality of ephemeral streams or increased discharge of contaminated groundwater to surface waters? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in .Appendix C.3. X Provide basis: It is our opinion there are no adverse impacts to water balance impacts to stream flow, or impacts on any downstream water rights. rt should be noted that researching downstream water rights or evaluating water balance issues to stream flows is beyond the scope of the geotechnical consultant. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability. Part 1 Resul~ If all answers to rows 1 -4 are "Yes" a full infiltration design 1s potentially feasible. The feasibility screening category is Full Infiltration If any answer from cow 1-4 is "No" infiltration may be possible to some extent but would not genernlly be feasible or desirable to achieve a "full infiltration" design. Proceed to Part 2 No. See Part 2 *To be completed using gathered site information and best professional judgment considering the definition of MEP in the MS4 Permit. Additional testing and/ or studies may be required by City Engineer to substantiate findings. Form 1-8 Page 3 of 4 Pan 2-Partial ln.6lttation vs. No Infiltration Feasioility Screening Criteria Would infiltration of water in any appreciable amount be physically feasible without any negative consequences that cannot be reasonably mitigated? Criteria Screening Question 5 Do soil and geologic conditions allow for infilt(ation in any appreciable race or volume? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2 and Appendi" D. Yes No X Provide basis: The infiltration test results did not meet the minimum threshold of 0.0 I iph for partial infiltration. Saturating compacted fill may result in settlement and distress to nearby public roadway improvements and proposed private improvements and structures. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability and why it was not feasible to mitigate low infiltration races. 6 Can Infiltration in any appreciable quantity be allowed without increasing risk of geotechnical hazards (slope stability, groundwater mounding, utilities, or other factors) that cannot be mitigated to an acceptable level? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2. X Provide basis: The adverse impacts of partial infiltration could be reasonably mitigated to acceptable levels using side liners and a subdrain. However, infiltrating into compacted fill is not recommended. Any infiltration BMP's should be founded in the formational materials and side liners should be used to prevent lateral water migration and daylight water seepage from adversely impacting the compacted fill and slopes. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability and why it was not feasible co mitigate low infiltration rates. form 1-8 Pagl' 4 of 4 Criteria Screening Question 7 Can Infiltration in any appreciable quantity be allowed without posing significant risk for groundwater related concerns (shallow water tllble, storm water poUutants or other factors)? The response ro this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3. Yes No X Provide basis: Groundwater is not located within approximately IO feet from the bottom of the proposed basins. Summarize findings of studies; provide reference co studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability and why ir was nor feasible to mitigate low infiltration rates. 8 Can infiltration be allowed without violating downstream water eights? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3. X Provide basis: Geocon is not aware of any downstream water rights that would be affected by incidental infiltration of storm water. Researching downstream water rights is beyond the scope of the geotechnical consultant. Summacizc findings of studies; provide reference to studies, calculations, maps, data sources, ere. Provide narrative discussion of study /data source applicability and why it was not feasible to mitigate low infiltration rates. Part 2 Result"' If all answers from row 1-4 are yes then partial infiltration design is potentially feasible. The feasibility screening category is Partial Infiltration If any answer from row 5-8 is no, then infiltration of any volume is considered to be infeasible within the drainage area. The feasibility screening category is No Infiltration. Infiltration "To be completed using gathered site information and best professional judgment considering the definition of MEP in the MS4 Permit. Additional testing and/or srudics may be required by City Engineer to substantiate findings ~ Soil Map-San Diego County Area, California (Carlsbad Oaks North -Lot 1) MAP LEGEND MAP INFORMATION Area of Interest (AOI) D Area of Interest (AOI) Soils D Soil Map Unit Polygons -Soil Map Unit Lines ■ Soil Map Unit Points Spacial Point Features ~ Blowout l8J Borrow Pit * Clay Spot ◊ Closed Depression X Gravel Pit . .. Gravelly Spot 0 Landfill A. Lava Flow • Marsh or swamp ~ Mine or Quarry 0 Miscellaneous Water 0 Perennial Water V Rock Outcrop + Saline Spot . .. Sandy Spot • Severely Eroded Spot 0 Sinkhole ~ Slide or Slip /II Sadie Spot Natural Resources Conservation Service 13 Spoil Area 0 Stony Spot a) Very Stony Spot ~ Wet Spot (!l Other .. Special Line Features Water Features Streams and Canals Transportation +++ Rails -Interstate Highways -US Routes Major Roads Local Roads Background • Aerial Photography Web Soil Survey National Cooperative Soil Survey The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soll Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used If more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: San Diego County Area, California Survey Area Data: Version 10, Sep 12, 2016 Soil map units are labeled (as space allows) for map scales 1 :50,000 or larger. Date(s) aerial images were photographed: Nov 3, 2014-Nov 22,2014 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. 9/20/2017 Page 2 of 3 Soil Map-San Diego County Area, California Map Unit Legend Map Unit Symbol CIG2 HrD Totals for Area of Interest Natural Resources Conservation Service San Diego County Area, California (CA638} Map Unit Name Acres In AOI Cieneba coarse sandy loam, 30 to 65 percent slopes, ero ded Huerhuero loam, 9 to 15 percent slopes Web Soil Survey National Cooperative Soil Survey 3.1 4.0 7.2 Carlsbad Oaks North -lot 1 Percent of AOI 43.7% 56.3%1 100.0% 9/20/2017 Page 3 of 3 Map Unit Description: Cieneba ooarse sandy loam, 30 ta 65 percent slopes. era ded--San Diego County Area, California Carlsbad Oaks North -Lot 1 !l,liil San Diego County Area, California CIG2-Cieneba coarse sandy loam, 30 to 65 percent slopes, eroded Natural Resources Conaervation Service Map Unit Setting National map unit symbol: hb9s Elevation: 500 to 4,000 feet Mean annual precipitation: 12 to 35 inches Mean annual air temperature: 57 to 64 degrees F Frost-free period: 200 to 300 days Fann/and classification: Not prime farmland Map Unit Composition Cieneba and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Cieneba Setting Landform: Hills Landform position (two-dimensional): Backslope Landform position (three-dimensional): Side slope Down-slope shape: Convex Across-slope shape: Convex Parent material: Residuum weathered from granite and granodiorite Typical profile H1 -Oto 10 inches: coarse sandy loam H2-10 to 14 inches: weathered bedrock Properties and qualities Slope: 30 to 65 percent Depth to restrictive feature: 4 to 20 inches to paralithic bedrock Natural drainage class: Somewhat excessively drained Runoff class: Medium Capacity of the most limiting feyer to transmit water (Ksat): High (1.98 to 5.95 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Very low (about 1.0 inches) Interpretive groups Land capability classification (irrigated): 7e Land capability classification (nonirrigated): 7e Hydrologic Soil Group: D Ecological site: SHALLOW LOAMY (1975) (R019XD060CA) Hydric soil rating: No Web Soil Survey National Cooperative Soll Survey 9120/2017 Page 1 of2 Map Unit Description: Cieneba coarse sandy loam, 30 to 65 percent slopes, ero ded---Sen Diego County Area, California Minor Components Vista Percent of map unit: 1 0 percent Hydric soil rating: No Las posas Percent of map unit: 5 percent Hydric soil rating: No Data Source Information Soil Survey Area: San Diego County Area, California Survey Area Data: Version 10, Sep 12, 2016 Natural Resources Conservation Service Web Soil Survey National CooperaUve Soil Survey Carlsbad Oaks North -Lot 1 9120/2017 Page 2 of2 Map Unit Description: Huerhuero loam, 9 to 15 percent slopes--San Diego County Area, California San Diego County Area, California HrD-Huerhuero loam, 9 to 15 percent slopes Natural Reaources Conservation Servica Map Unit Setting National map unit symbol: hbcp Elevation: 1,100 feet Mean annual precipffation: 12 to 20 inches Mean annual air temperature: 57 degrees F Frost-free period: 260 days Farmland classification: Not prime farmland Map Unit Composition Huerhuero and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Huerhuero Setting Landform: Marine terraces Down-slope shape: Concave Across-slope shape: Concave Parent material: Calcareous alluvium derived from sedimentary rock Typical profile H1 -0 to 12 inches: loam H2-12 to 55 inches: clay loam, clay H2 -12 to 55 inches: stratified sand to sandy loam H3 -55 to 72 inches: Properties and qualities Slope: 9 to 15 percent Depth to restn'ctive feature: More than 80 inches Natural drainage class: Moderately well drained Runoff class: Very high Capacffy of the most limiting layer to transmit water (Ksat): Very low to moderately low (0.00 to 0.06 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Sodium adsorption ratio, maximum in profile: 25.0 Available water storage in profile: Moderate (about 6.6 inches) Interpretive groups Land capability classification (irrigated): 4e Land capability classification (nonirrigated): 4e Hydro/ogic Soil Group: D Web Soil Survey National Cooperatfve Soil Survey Carlsbad Oaks Norlh -Lot 1 9120/2017 Page 1 of2 Map Unit Description: Huerhuero loam, 9 to 15 percent slopes--San Diego County Area, California Ecological site: CLAYPAN (1975) (R019XD061CA) Hydric soil rating: No Minor Components Las flares Percent of map unit: 1 0 percent Hydric soil rating: No Oliventain Percent of map unit: 3 percent Hydric soil rating: No Unnamed Percent of map unit: 2 percent Hydric soil rating: No Data Source Information Soil Survey Area: San Diego County Area, California Survey Area Data: Version 10, Sep 12, 2016 Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey Carlsbad Oaks North -Loi 1 9/20/2017 Page 2 of2