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<br /> <br />ASSOCIATED SOILS ENGINEERING, INC. Project No.: 7160.23 <br />2860 Walnut Avenue, Signal Hill CA 90755 January 23, 2024 <br />Tel: (562) 426 -7990 * Fax: (562) 426 -1842 Page 4 <br />sandy silts, silty sands, and gravel. Figure 2, Local Geologic Map, excerpted from Reference 2, shows <br />geologic material distribution in the vicinity of the Site. <br /> <br />Blow counts recorded from advancing Modified California barrel sampler empirically indicate that <br />the granular, sandy strata of site native alluvial soils were in a medium dense to very dense <br />condition, whereas the fine-grained, cohesive strata encountered (i.e. sandy silts) were generally in <br />a firm to stiff condition. Site subsurface soils were, in general, in a dry to moist condition within the <br />explored depths at the time of ASE’s site investigation. <br /> <br />More detailed descriptions of soils encountered and conditions observed during the subsurface exploration <br />are shown in the Field Logs of Boring ("B" Plates) and Field Logs of Percolation Boring (“B-P” Plates) in <br />Appendix A, together with information of soil classifications, depths and types of soil samples, blow counts, <br />field dry densities and moisture contents, and corresponding laboratory tests performed. <br /> <br /> 2.3 Groundwater and Caving <br />During field exploration, groundwater was not encountered in ASE’s exploratory borings to the maximum <br />explored depth of 26 feet in Boring B-1. Published groundwater data in Reference 4 indicates that the <br />historic high groundwater levels in the vicinity of the Sites are approximately 40 feet deep. A search on <br />Google Earth indicates that the Site is approximately 129 to 132 feet above Mean Sea Level (MSL). <br /> <br />Information available from the State of California Water Resources Control Board Geotracker website <br />(http://geotracker.waterboards.ca.gov) indicates that the groundwater elevation in groundwater <br />monitoring well B-22, (UNOCAL #4991: 1601 East 1st Street – located approximately 1/4 mile northwest of <br />the Site), was 63.4 below grade on May 29, 2007, which was the most recent reading in this well. The <br />ground surface elevation at this well location (taken from Google Earth images) is approximately 131 feet <br />above MSL, which is approximately the same as the Site grades. <br /> <br />Additional information available from the same Geotracker website indicates that the groundwater <br />elevation in groundwater monitoring well MW-7, (Thrift Oil $377/ ARCO #7741: 324 South Grand Avenue – <br />located approximately 1/2 mile west of the Site), was 64.57 below grade on June 22, 2005, which was the <br />most recent groundwater reading in the well. The ground surface elevation at this well location (taken from <br />Google Earth images) is approximately 122 feet above MSL, which is approximately 7 to 10 feet lower Site <br />grades. <br /> <br />Generally, seasonal and long-term fluctuations in the groundwater may occur as a result of variations in <br />subsurface conditions, rainfall, run-off conditions and other factors. Therefore, variations in groundwater <br />levels from the short-term observations made in ASE’s exploratory borings cannot be ruled out. Please <br />notes that ASE’s exploratory borings were not meant for groundwater monitoring.