Geotechnical Engineering Report 12 10 2024 submission

Mavis Store #2296 December 10, 2024 ECS Project No. 44:2100 Page 12 could result in a reservoir condition, allowing the accumulation of water and potential softening of the bearing soils. It is important to have ECS observe subgrade conditions prior to placing foundation concrete or Granular Capillary Break/Drainage Layer for ground-supported slabs to document the bearing soils are what was anticipated and the extent of undercutting necessary, if any. Some undercutting and replacement should be anticipated within the new building footprint. 5.1.5 Site Temporary Dewatering The contractor must make its own assessment of temporary dewatering needs based upon the limited subsurface groundwater information presented in this report. Soil sampling is not continuous, and thus soil and groundwater conditions may vary between sampling intervals. If the contractor believes additional subsurface information is needed to assess dewatering needs, they should obtain such information at their own expense. ECS makes no warranties or guarantees regarding the adequacy of the provided information to determine dewatering requirements; such recommendations are beyond our scope of services. Dewatering systems are a critical component of many construction projects. Dewatering systems must be selected, designed, and maintained by a qualified and experienced (specialty or other) contractor familiar with the succinct geotechnical and other aspects of the project. The failure to properly design and maintain a dewatering system for a given project can result in delayed construction, unnecessary foundation subgrade undercuts, detrimental phenomena such as ‘running sand’ conditions, internal erosion (i.e., ‘piping’), the migration of ‘fines’ down-gradient towards the dewatering system, localized settlement of nearby infrastructure, foundations, slabs-on-grade and pavements, etc. Water discharged from any site dewatering system must be discharged in accordance with all local, State, and Federal requirements. We anticipate that effective, short-term dewatering operations can be managed by using trash pumps or conventional submersible pumps directly in open excavations for the construction of the shallow foundations. 5.2 EARTHWORK

ive, short-term dewatering operations can be managed by using trash pumps or conventional submersible pumps directly in open excavations for the construction of the shallow foundations. 5.2 EARTHWORK OPERATIONS 5.2.1 Existing Man-Placed Fill Existing fill materials were encountered in each of the borings. Other localized areas of undocumented fill may still be present at the site. If during construction deeper undocumented fill materials are encountered, the Geotechnical Engineer should be contacted to evaluate and provide recommendations. Considering the homogenous nature of the materials, the existing fill can remain in place below proposed pavements and the pad provided it is stable during proofrolling operations. However, if construction debris and/or previous remanence of previous development are encountered, ECS should be contacted to further evaluate the site conditions. In parking areas, if undercutting does not resolve localized areas of instability, the undercut should be stopped at a depth of 2 feet below subgrade and the exposed subgrade should then be covered with bi- axial or tri-axial geogrid (BX-1200, TX-160 or equivalent) or reinforcing geotextile fabric (Amoco 2006 or equivalent) prior to placement of new fill. In undercut areas, the new fill should consist of select granular fill, such as crushed stone or highway base stone.