2600 FEDERAL AVE 2021 PORT OF EVERETT 2025-09-29

Substantive Requirements Review Landau Associates The use of wells or well points may be necessary where utility excavations extend below the water table. This will be especially critical for deeper stormwater vaults and electrical vaults. Use of well points is a viable option for lowering groundwater to a depth of approximately 17 ft below the pump elevation. The Contractor should be responsible for the design, installation, monitoring, and maintenance of required dewatering system(s). If wells or well points are necessary, a registered professional engineer or hydrogeologist should prepare a dewatering plan. Prior to implementation, the Contractor should submit the plan for the design team's review and comment. 3.2.5 Structural Fill Structural fill beneath pavements must be properly placed and compacted. Non-organic, predominately granular soil may be used, provided the material is properly moisture-conditioned prior to placement and compaction. Excavated material containing organic matter or construction debris is not considered suitable for reuse as structural fill and should be disposed of at an approved offsite location. Moisture-sensitive site soils are not recommended for reuse as structural fill. The sand fill placed during K-C's backfilling operation contains limited fines and is anticipated to be suitable for reuse with proper placement and compaction. The suitability of imported soil for use as structural fill will depend on the gradation and moisture content of the soil when it is placed. As the amount of fines (the portion passing the U.S. Standard No. 200 sieve) increases, the soil becomes increasingly sensitive to small changes in moisture content, and adequate compaction becomes more difficult to achieve. Soil containing more than about 5 percent fines cannot consistently be compacted to a dense, unyielding condition when the water content is more than 2 to 3 percent above optimum. Optimum moisture content is that at which the greatest compacted dry density can be achieved. Structural fill should be placed and compacted in accordance with the requirements in Section 2-03.3(14)C, Method C of the 2020 WSDOTStandard Specifications. Structural fill placed beneath paved areas or buildings should be compacted to at least 95 percent of its MDD, determined in accordance with ASTM standard test method D1557. 3.3 Pavement Design LAI understands that the Port has elected to use a typical Puget Sound area port facility pavement section that consists of 9 inches of HMA over 12 inches of base course. Site subsurface conditions are variable, and pavements, even those constructed in accordance with the design recommendations herein, will likely require higher than average maintenance costs over the lifetime of the project. Figure 8 shows areas of the site where design recommendations for preload, multi-layer geogrid reinforcement and single-layer geogrid reinforcement may be applicable. These areas are based on LAI's observations during CM fill removal. Some structures may not have been uncovered during removal, and variable pavement performance should be anticipated. Geotechnical Engineering Report 0121049.040.041 Norton Terminal Development&MTCA 3rd Interim Action 3-4 May 7,2021