Environmental Declaration WPCP 20240409

Home

L A SAN LEANDRO TREATMENT WETLAND PROJECT r`. SA LEAN DROP ALAMEDA COUNTY, CALIFORNIA 2.2.2 Federally Listed Fish and Essential Fish Habitat Protection Measures BIOLOGICAL ASSESSMENT APRIL 2020 The avoidance and minimization measures described below have been incorporated into the project and will serve as mitigation measures to offset potential effects to the federally listed fish species potentially present in the Action Area and to EFH. Most of these measures are adapted from the NMFS Non fishing Impacts to Essential Fish Habitat and Recommended Conservation Measures (Hanson et al. 2003). The following measures will be implemented for the proposed project. 2.2.2.1 General Endangered and Threatened Species Measures Daylight Working. All work will be conducted during daylight hours, and no artificial illumination will be used. Work Areas. Personnel will limit their entry into the immediate vicinity of the project area. All personnel and their equipment will be required to stay within the designated work areas to perform job -related tasks and will be directed to stay out of surrounding areas. In -water work will be performed at low tide when the outfall is exposed on the mud flat and will occur outside the primary salmonid migration window (June 15 to November 30). If replacement and/or major retrofits of the outfall are required, a cofferdam will be installed between the bank where the outfall work will occur and the edge of the tidal slough. The cofferdam will be installed at low tide when fish are not present and will be made of sand bags, clean gravel bags, sheet piles, or other suitable material. The cofferdam will be installed to isolate the immediate work area from the rest of the tidal slough, as well as to prevent sediment from flowing into the slough and from fish entering the work area. The following conservation measures will be implemented to reduce potential impacts to fish and EFH: ■ When possible, in -water work shall be conducted at low tide when fish are not present. ■ If in -water work cannot be avoided, working outside of the primary salmonid migration window (June 15 to November 30) will limit the presence of listed salmonids in the Action Area. Green sturgeon can be present in the area year-round. • The cofferdam shall be completely removed after completion of the in -water work. The suspension of sediments and disturbance of the substrate shall be minimized. Measures to help accomplish this include, but are not limited to, the following: When practicable, the cofferdam shall be removed with a vibratory hammer, rather than the direct pull or clamshell method. The cofferdam shall be slowly removed to allow sediment to slough off at, or near, the mudline. 16 P:\TER2001\BA\$an Leandro Treatment Plant BA 4-7-20.docx (04/07/20)