2024 Addendum to the City of Alameda Dredged Material Management Program 2014 Initial Study and Mitigated Negative Declaration

2024 Addendum to the City of Alameda Dredged Material Management Program 2014 Initial Study and Mitigated Negative Declaration

The proposed Lagoon 5 maintenance dredging consists of excavating, transporting, and disposing of sediment. The majority of the target area in Lagoon 5 was not originally identified as a priority area in the 2014 IS/MND and was not dredged in 2014 or 2020. Detailed plans are provided as Attachment A. Dredging of 360 cubic yards of sediment from approximately 6,800 square feet of Lagoon 5 would occur in wetted conditions (normal water levels). Dredging will be accomplished using a bargemounted excavator. Equipment staging, barge installation and removal, and sediment offloading will occur along Waterton Street, southeast of the Waterton Street and Mound Street intersection. Excavated material will be directly placed into dumpster bins on a barge or barges for dewatering. Barge dewatering (draining off excess water) is required because there is no suitable stockpile location for dewatering and drying of spoils outside of the lagoons. Silt curtain will be used to segregate impacted dredge and dewatering areas to prevent suspended solids from increasing total suspended solid (TSS) concentrations in areas of the lagoon not being dredged. When sediment dewatering (or drying) on barges is complete, an excavator (barge or land based) would move sediment into dump trucks for transport to a licensed landfill. Alternatively, the dumpsters may be craned off the barges and placed directly onto trucks for transport to a licensed landfill. Bentonite desiccant would be mixed into the sediment, as necessary, to further dry material in preparation for transport to the landfill; mixing of desiccant will take place while sediment is in containment, either inside of the dumpsters or inside of haul trucks.

Alameda

Alameda

San Francisco Bay Area

California Air Resources Board (ARB), California Department of Conservation (DOC), California Department of Fish and Wildlife, Bay Delta Region 3 (CDFW), California Department of Transportation, District 4 (DOT), California Department of Transportation, Division of Aeronautics (DOT), California Department of Water Resources (DWR), California Highway Patrol (CHP), California Native American Heritage Commission (NAHC), California Natural Resources Agency, California Regional Water Quality Control Board, San Francisco Bay Region 2 (RWQCB), California State Lands Commission (SLC), San Francisco Bay Conservation and Development Commission (BCDC), State Water Resources Control Board, Divison of Financial Assistance

Other (Dredging for stormwater lagoon)

Coastal Permit

Coastal Zone