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

ASPECT CONSULTING 68 FINAL PROJECT NO. AS190583A-08  MAY 21, 2025  Additional soil from the Boiler-Baghouse area, which also included the GF-B-12 area  REC5-MW-1 area  BA-MW-7 area  Digester Trench area 6.2.3 Unit C The unit boundaries, current and historical features, IA excavation areas, and collective explorations for Unit C are depicted on Figure 6-C1. The historical operational areas identified within Unit C are the following:  Former Log Pond  Hydraulic Barker Building area  Engineering/Maintenance Building area  Chip Screen Building area  Small Hydraulic Barker Building area During the first IA, the only IA area within Unit C was the SHB-MW-1 area (Aspect, 2015a). During the second IA, the IA areas within Unit C were as follows (Aspect, 2021):  Log Pond Chip Conveyor area  Hydraulic Barker area The northern boundary for Unit C has been slightly adjusted from its previous configuration defined in Aspect (2013c) to include the entire extent of the Former Log Pond. Given this adjustment, a portion of Snohomish PUD’s electrical substation is located within Unit C. The electrical substation is not currently in operation. No other structures remain within Unit C. 6.2.4 Unit D The unit boundaries, current and historical features, IA excavation areas, and collective explorations for Unit D are depicted on Figure 6-D1. Currently, no structures from the mill remain within Unit D. The only existing structure within Unit D is a portion of Snohomish PUD’s electrical substation, which is not currently in operation. The historical operational areas identified within Unit D are the following:  Main operational area of the Clark-Nickerson (CN) Lumber Mill  Former Naval Reserve Property  Tissue Mill area of the K-C Mill During the first IA, the IA areas within Unit D were the following (Aspect, 2015a):  Naval Reserve Parcel UST area  Naval Reserve Parcel South area  CN-B-2 area