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

ASPECT CONSULTING 30 FINAL PROJECT NO. AS190583A-08  MAY 21, 2025 but was detected at concentrations of 53,000 mg/kg and 7,000 mg/kg in the 7.5-foot and 9-foot soil samples, respectively. According to the report, “groundwater and pilings driven randomly spaced at about 8-feet bgs impeded further excavation; therefore, soil excavation was suspended, and the pits backfilled with pea gravel to approximately 1 foot above groundwater. The remaining excavations were filled to grade with clean backfill material.” The report also states that additional TPH-contaminated soil identified beneath the boiler room was removed, but does not provide location information or verification soil sample data for the excavation. Likewise, the report states that 15 cubic yards of lead- contaminated soil was removed from beneath the Firing Range building, but does not provide location information or verification soil sample data for the excavation. In August 1997 through October 1998, following demolition of the facility structures, Foster Wheeler conducted characterization soil sampling and analysis from the USTs area, adjacent bilge water tank location and flammable material storage shed, and the Firing Range area. Twenty-four drilled soil borings were advanced to depths of approximately 10 feet bgs in the Building 1 area to characterize soil quality around the USTs, bilge water tank location, and flammable material storage shed. Four additional hand-augered borings were also sampled to depths of 1.25 feet bgs around the flammable material storage shed. Twenty-one hand-augered borings were sampled to depths of 3 feet bgs at the Firing Range. The first 14 borings were sampled in September 1997, and the last seven in October 1997; the report presents locations only for the first 14 borings. Following soil removal and site restoration, two monitoring wells were installed in the most contaminated areas to monitor groundwater quality as a reflection of the soil removal effectiveness. The wells were identified as North Well and South Well, but the report does not present locations for them. The January 1998 groundwater samples collected from the two wells contained no detectable TPH or BTEX, and concentrations of the polycyclic aromatic hydrocarbons (PAHs) acenaphthene, fluorene, and naphthalene (up to 4 µg/L) were less than respective groundwater screening levels. 3.1.8 Investigation of Bulk Fuel Facilities (1998) On behalf of K-C, Chevron, Texaco, and BNSF, Pacific Environmental Group (PEG) conducted a subsurface investigation to assess petroleum hydrocarbon contamination previously encountered adjacent to the City of Everett Combined Sewer Outfall (CSO) line which runs east-west immediately south of the K-C distribution warehouse in the southeast corner of the mill property, within the Everett Avenue easement. In 1995, petroleum product had been observed discharging from the CSO line into the East Waterway. Investigation determined that petroleum product was entering a segment of the CSO line that was constructed of clay tiles that had settled and cracked. In summer 1996, portions of the CSO line were replaced, and the remaining portions of it were slip-lined. Reportedly, 1,450,800 gallons of water and 23,050 gallons of petroleum product were removed by dewatering conducted during the construction (AMEC, 2010). The purpose of the PEG (1998) investigation was to evaluate soil and groundwater quality in the vicinity of petroleum product bulk facilities located north of the CSO (Standard Oil