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

ASPECT CONSULTING 60 FINAL PROJECT NO. AS190583A-08  MAY 21, 2025 In addition to these pathways, contaminants in soil can leach to groundwater, acting as a secondary source. The K-C Upland Area qualifies for an exclusion from conducting a terrestrial ecological evaluation (TEE) in accordance with WAC 173-340-7491(1)(b). That exclusion specifies that no TEE is required if: “All soil contaminated with hazardous substances is, or will be, covered by buildings, paved roads, pavement, or other physical barriers that will prevent plants or wildlife from being exposed to the soil contamination. To qualify for this exclusion, an institutional control shall be required by the department under WAC 173-340-440. An exclusion based on planned future land use shall include a completion date for such development that is acceptable to the department.” These conditions will be met for the planned future use of the Upland Area. Under the planned future land use, soil across the entire Upland Area, contaminated or not, will be covered by pavement, buildings, and/or landscaped areas (soil covers) that provide an effective physical barrier to prevent plants or wildlife from being exposed to underlying soil contamination where present. In conjunction with the environmental capping, an institutional control (environmental covenants) would be executed by the City and by the Port, in accordance with WAC 173-340-440, requiring the periodic inspection and maintenance of the environmental caps after the cleanup action is implemented. These cleanup elements would be incorporated into the CAP for the Upland Area. The completion date for achieving the required containment of the Upland Area soil will be determined with Ecology by the time the CAP is executed. 5.2.2 Groundwater Exposure Pathways Section 5.1 of the RI/FS Work Plan (Aspect, 2013c) explains the rationale for classifying the Upland Area groundwater as nonpotable water in accordance with WAC 173-340-720(2). That information is not reiterated herein. Because of this classification, potable use of groundwater is not considered a potentially complete exposure pathway. Current and future potentially complete exposure pathways for groundwater include the following:  Construction or utility workers contacting contaminated groundwater during excavation or other construction-related activities;  Industrial or commercial workers (including construction workers) inhaling indoor or outdoor air containing contaminants that have volatilized from shallow groundwater;  Marine ecological receptors receiving direct exposure to groundwater contaminants discharged to sediment or surface water; and  Higher-trophic-level marine organisms or humans consuming marine ecological receptors contaminated by groundwater discharges to sediment or surface water.