WA State Dept of Ecology 9/18/2023

Joel Haack January 6, 2023 Page 4 • Soil MTCA Method A soil cleanup levels for unrestricted uses (WAC 173-340-740(2);Table 740-1) with the standard point of compliance throughout the Site to a depth of 15 feet bgs (WAC 173-340-740(6)(d)) are appropriate. A Terrestrial Ecological Evaluation (TEE) has already been completed for this Site in previous investigations.The standard Method A soil cleanup levels and point of compliance as discussed above are appropriate at the Site. Selecting the cleanup action for the Property Ecology has determined the cleanup action you selected for the Property meets the substantive requirements of MTCA. The cleanup meets the minimum cleanup requirements and does not preclude reasonable cleanup alternatives elsewhere at the Site per WAC 173-340-360(2). The cleanup action selected in the Cleanup Action Report, Legion Lots Haack Parcels, 413 and 419 Rockefeller Avenue, Everett Washington, dated May 2, 2022 (2022 CAR), includes the excavation and off-Property disposal of soils containing arsenic, lead, and cadmium above the Method A cleanup levels.This cleanup action is protective of exposure pathways at the Property and does not disturb the existing cleanup at the remainder of the Site. Implementing the cleanup action Ecology has determined your cleanup of the Property meets the cleanup standards set for the Site. The cleanup involved the removal of contaminated soil from the Site, described in detail in Enclosure C. A total of approximately 805 tons of soils contaminated with arsenic, lead, and cadmium were excavated from 6 excavation areas on the Property. Performance soil samples collected from the final limits of each excavation confirmed that the remedial excavations were successful in removing all soil containing arsenic, lead, and cadmium above the Method A cleanup levels from the Property. One soil sample collected from the eastern sidewall of Excavation 3 contained arsenic above the Method A cleanup level (Enclosure C, Figure 7).This sample was collected along the eastern Property boundary with LMGC and is representative of conditions on that parcel. Due to the complete removal of all soils containing arsenic, lead, and cadmium above cleanup levels from the Property, no further action is needed to ensure cleanup standards are met on the Property.