3815_PGSF WMVD Pkg 2_Vol 4-3_03.03.2026_BXWA_Certified

3rd Interim Action Construction Report Kimberly-Clark Upland Site 0121049.080.084 July 30, 2024 2-9 landauinc.com 2.6.1.4 Wood Chips Wood chips, some with a petroleum odor, were observed in discontinuous areas from an approximately 20-ft by 20-ft by 3-ft-deep area to the south and southwest of the existing public utility district (PUD) substation, generally within the historical “log pond fill area,” as shown on as-built figure G2.1 (Appendix A). Photographs of this material are included in Appendix D. Wood chips were excavated where proof rolling of existing soils indicated a soft subgrade; thin lenses of wood chips were observed in the sidewalls outside of excavated areas and at depths beyond the maximum excavation depth of 3 ft bgs. Additional wood chips may be present in the area southwest of the existing PUD substation, but observations indicated that the most concentrated volumes of wood chips were within 3 ft of the ground surface, which was removed. After excavation, the wood chips were managed as potentially contaminated soil stockpile for offsite disposal as described above in 2.6.1.1. 2.6.2 Management of Groundwater To facilitate construction, groundwater encountered during excavation was dewatered using sumps or well points, as needed, and was managed in accordance with the SGMP. Collected groundwater was conveyed to settling tanks operated by the Port’s contractor, who tested the water to verify compliance with the discharge authorization prior to discharge to the City of Everett’s sanitary sewer collection system in accordance with a City of Everett Discharge Authorization No. MD-41-2021 (Appendix F). Approximately 7.1 million gallons of groundwater were treated and discharged to the City’s sanitary sewer. No groundwater was managed by infiltration at the Site. 2.6.2.1 Monitoring Well Decommissioning Existing monitoring wells within the extent of the Project were decommissioned in accordance with the Work Plan and resource protection well decommissioning requirements presented in Washington Administrative Code (WAC) 173-160-460. A total of 10 monitoring wells were decommissioned. Decommissioned monitoring wells include the eight monitoring wells decommissioned on October 14, 2021; the locations of these wells are shown on as-built sheets D1.1 through D1.8 (Appendix A). Two additional wells were decommissioned in the northeast corner of the Site on November 23, 2022 to accommodate additional paving. The location of decommissioned monitoring well UG-MW-1 is shown on sheet G3.1 (Appendix A); the second of the two additional wells was located approximately 95 ft directly north of UG-MW-1. This well did not have an Ecology well identification (ID) tag, and no records of this well were located; the well was approximately 57 ft deep and was constructed with a 1-inch polyvinyl chloride (PVC) well casing. The unknown well was removed by overdrilling and was filled with grout and bentonite chips.