400 RIVERSIDE RD SEPA 016 - 039 - RIVERSIDE BUSINESS PARK Land Use Decision Documents 2025-04-14

present on the site and could be encountered during construction below the former Weyerhaeuser working surface. Additionally, because the pathways by which site contaminants have migrated are ' not clearly defined, construction personnel should exercise due caution when excavating existing soil • below the former Weyerhaeuser working surface to minimize the health hazard posed to all onsite project participants" (Landau Associates, 2015). These measures will be a part of the current projects ' construction TESC, SWPPP, SPCCC and construction safety plans. 4.2 Soils/Geology The Natural Resources Conservation Service soil map indicates that a majority of the site is underlain by urban land,which are compacted soils consisting of various types and sizes of fill overlain by a thin ' stratum of soil. Refer to Chapter 4, section 4.1. 4.3 Vegetation iUplands are dominated by Himalayan Blackberry, Scotch broom, nonnative and native grasses and a few cottonwoods along the shoreline. Further inland is a mixture of fallow fields and invasive 1 scrub/shrub species and grasses. Refer to Appendix B9 Site Photos. 4.4 FEMA Mapped Floodplain ' FEMA maps accessed through FEMA's Map Service Center indicated the project site is located within the 100-year floodplain, or those areas with 1 percent chance of flooding in any given year, of the Snohomish River. The currently proposed actions are situated within the 100-year floodplain of the ' Snohomish River. 4.5 Snohomish River Watershed Conditions In a 2016 report, the Tulalip Tribes summarized the state of the Snohomish River Watershed. They summarized the following current conditions: ' "Over 30% of the feeder bluffs and accretion shoreline beaches along Whidbey basin nearshore are already armored and directly impacting forage fish that are key to juvenile Chinook survival.1,2 Nearly every feeder bluff along the Snohomish nearshore south from ' Everett to Mukilteo has been cut off from the shoreline,impounded to protect the Burlington Northern Santa Fe Railroad.The estuary has had 80-85%of its historic wetland habitat cleared and drained, resulting in the potential juvenile Chinook losses of between 1 and 1.6 million per year" (Tulalip Tribes, 2016). The report stated that the regulatory framework for salmon recovery has been ineffective and activities ' are not meeting the five principles established in the Snohomish Basin Salmon Conservancy plan. • Protection and reconnection of habitat; ' • Use of historical information to guide decisions; • Preserve and restore ecosystem processes; • Use monitoring and assessment for adaptive management projects; ' • Preserve options for the future. (Tulalip Tribes, 2016). The report also states that restoration projects have been improving portions of the basin, but that ' other essential ingredients to improve the degraded watershed have been declining still, including Soundview Consultants LLC December 8,2016 1413.0003 Riverside Business Park—FEMA ESA Habitat Assessment Report Page 10