2600 FEDERAL AVE 2021 PORT OF EVERETT 2025-09-29

1q:1 Consulting Engineers Page 3 of 13 During the recent 2nd Interim Action cleanup, all but two outfalls were plugged and abandoned. The two remaining outfalls, A and M, will be replaced to serve the proposed redevelopment. Table 1: EXISTING SITE AREA CHARACTERISTICS Basin Area Impervious Pervious (ac) Area (%) Area (%) Basin M 39.40 10 90 Basin Al 4.24 94 6 Future PUD Substation 1.86 34 66 Area Total Basin Area 45.37 19 81 1. Basin A area includes 0.13ac of off-site paved area. Basin M includes much of the upland area above the Ordinary High Water elevation and is approximately 39.40 acres. The existing surface characteristics of Basin M are primarily of sand backfill that was placed during removal of crushed material as part of the interim action cleanup project and some small remnant asphalt and concrete pavement along the perimeter of the basin. See Table 2: Existing Basin M Site Characteristics below for a summary of Basin M site characteristics. Existing soil conditions consist of granular/sandy fill material which allows stormwater runoff to infiltrate.As part of the cleanup action,the site has been graded to slope away from the shoreline to a low lying area where drainage is infiltrated to reduce the risk of runoff flowing to Port Gardner Bay. Table 2: EXISTING BASIN M SITE CHARACTERISTICS Area Description Area (ac) Pavement 0.86 Gravel 7.50 Sand backfill 30.46 Gravel/vegetation 0.58 Total Basin Area 39.40 Basin A is a smaller basin located at the south end of the site and is approximately 4.24 acres.The surface characteristics of Basin A is primarily impervious area consisting of warehouse roof, parking areas, and remnant asphalt and concrete pavement located along the south and west sides of the basin. See Table 3: Existing Basin A Site Characteristics below for a summary of Basin A site characteristics.