DRAFT <br />to the newly placed utilities. Flooding or jetting of the trench backfill to achieve the <br />required compaction should not be permitted. In our opinion, the on-site gravel and <br />cobbles should typically not be used for utility trench backfill due to difficulties in <br />evaluating relative compaction without the use of field-density testing. <br />On-site soils and strippings that are relatively free of debris may be used as fill in <br />landscaped areas. These materials should be placed at about 90% of the maximum dry <br />density as determined by ASTM D698. The moisture content of soils placed in landscaped <br />areas is not as critical as the moisture content of soils placed as structural fill, provided <br />construction equipment can effectively handle the materials. <br />5.3 Temporary Excavations and Groundwater Management <br />5.3.1 General <br />Based on our understanding of the project, we anticipate the use of temporary excavations <br />will generally be limited to facilitating construction of new foundations and utilities. <br />Basements or other embedded structures are not currently planned for the project. Where <br />required, we anticipate temporary excavations for new foundations and utilities will <br />generally be less than about 5 feet and 10 feet deep, respectively. The method of <br />excavation and design of excavation support are the responsibility of the contractor and <br />are subject to applicable local, state, and federal safety regulations, including the current <br />Occupational Safety and Health Administration (OSHA) excavation and trench safety <br />standards. The means, methods, and sequencing of construction operations and site safety <br />are also the responsibility of the contractor. The information provided below is for the use <br />of our client and should not be interpreted to imply we are assuming responsibility for the <br />contractor's actions or site safety. <br />In our opinion, temporary excavations in the gravel and cobbles at the site will be a <br />significant consideration for the project, particularly in areas where the excavations extend <br />below the groundwater level. Based on the results of our investigation and our review of <br />current OSHA excavation and trench safety standards, we anticipate both Type B and C <br />soils will be encountered in temporary excavations completed at the site. However, Type <br />C soils will likely be encountered more frequently and will generally control utility trench <br />requirements. It should be noted that Type C soils require evaluation by a registered <br />professional engineer. <br />5.3.2 Groundwater Management <br />As previously discussed, groundwater levels at the site are relatively shallow and, <br />depending on the time of year the work is completed and the actual required depth of <br />excavations, groundwater seepage may be encountered in the temporary excavations. <br />Significant amounts of groundwater seepage were encountered in foundation excavations <br />GRI #6497-A - 2.MO Indoor Football Practice Facility Page 10 <br />August 26, 2021 <br />