3315 BROADWAY 2017 HOPEWORKS STATION 2 Geotech Report 2022-10-25

Hope Works Social Enterprises JN 17298 July 12, 2017 Page 3 Test Borings 1 and 2 were conducted along the western end of the subject site at the grade of Broadway Avenue. Test Boring 1, located in the southwest corner of the site and upslope of the existing concrete retaining wall, encountered approximately 7.5 feet of loose silty sand fill overlying medium-dense, native, slightly silty sand. The native soil became dense below a depth of 10 feet and very dense at a depth of 20 feet. Test Boring 2, located in the northwest corner of the subject site at the toe of the existing ecology block wall, encountered the dense slightly silty sand below a depth of 2.5 feet. The native soils became denser with depth; very dense sand was exposed below a depth of approximately 18 feet to the maximum-explored depth of about 21.4 feet. No obstructions were revealed by our explorations. However, debris, buried utilities, and old foundation and slab elements are commonly encountered on sites that have had previous development. Although our explorations did not encounter cobbles or boulders, they are often found in soils that have been deposited by glaciers or fast-moving water. Groundwater Conditions Slight perched groundwater seepage was observed at a depth of 8.8 to 15 feet in Test Boring 5 in the southeast corner of the subject site. The test borings were left open for only a short time period. Therefore, the seepage levels on the logs represent the location of transient water seepage and may not indicate the static groundwater level. Groundwater levels encountered during drilling can be deceptive, because seepage into the boring can be blocked or slowed by the auger itself. It should be noted that groundwater levels vary seasonally with rainfall and other factors. We anticipate that groundwater could be found in more permeable soil layers and between the looser near-surface soil and the underlying denser soil as observed in Test Boring 5. The stratification lines on the logs represent the approximate boundaries between soil types at the exploration locations. The actual transition between soil types may be gradual, and subsurface conditions can vary between exploration locations. The logs provide specific subsurface information only at the locations tested. If a transition in soil type occurred between samples in the borings, the depth of the transition was interpreted. The relative densities and moisture descriptions indicated on the test boring logs are interpretive descriptions based on the conditions observed during drilling. CONCLUSIONS AND RECOMMENDATIONS GENERAL THIS SECTION CONTAINS A SUMMARY OF OUR STUDY AND FINDINGS FOR THE PURPOSES OF A GENERAL OVERVIEW ONLY. MORE SPECIFIC RECOMMENDATIONS AND CONCLUSIONS ARE CONTAINED IN THE REMAINDER OF THIS REPORT.ANY PARTY RELYING ON THIS REPORT SHOULD READ THE ENTIRE DOCUMENT. Based on the provided preliminary plans and conversations with the project architect, Dykeman, we anticipate a bottom-of-excavation near elevations of 71 feet and 67 feet along the western and eastern ends of the building respectively. Dense to very dense slightly silty sand was encountered near 71 feet elevation along the western end of the proposed building. However, the depth to the dense slightly silty sand increased across the site from west to east, revealed near an elevation of GEOTECH CONSULTANTS,INC.