4849 SPIRE LN 2023 Geotech Report 2025-10-15

Proposed Remedial Lxcavation: 4849 Spire Lane, Everett, WA Decembe►- 8, 2022 maximum dry density, as determined using test method ASTM D 1557. If large compaction equipment such as a hoe-pac is utilized for compaction, lift thicknesses may be increased based on the soil type and actual size of compaction equipment. We recommend that hand - operated compaction equipment such as a jumping jack compactor be utilized within 5 feet of the adjacent structure, as large compaction equipment could create vibrations that may adversely affect the existing structure. WET WEATHER EARTHWORK In our opinion, the proposed excavation may be accomplished during wet weather without adversely affecting the site stability. However, earthwork construction performed during the drier summer months likely will be more economical. Winter/spring construction will require the implementation of best management erosion and sedimentation control practice to reduce the chances of off -site sediment transport. General recommendations relative to earthwork performed in wet conditions are presented below: • Sand bags or low berms should be used to prevent the flow of surface water into the excavation; • Surface water and groundwater that accumulates in the excavation should be pumped out of the excavation as soon as possible, to prevent the ponding of water; • Soil stockpiles should be covered with plastic sheeting; • Bales of straw, sandbags, and/or geotextile silt fences should be strategically located to control erosion and the movement of soil. Spilled soil should be swept off of the pavement areas to prevent the tracking of soil onto the right- of-way. CLOSURE We have prepared this report for use by 2018-2 IH Borrower LP, DBA, Invitation Homes, and the project team. Recommendations contained in this report are based on a site reconnaissance, the results of subsurface explorations conducted at the site, and our understanding of the project. The study was performed using a mutually agreed -upon scope of work. 22-389 4849 spire lane everett_.rpt.docx Page 10 PanGEO, Inc.