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LSA ASSOCIATES. INC. CEQA INITIAL STUDY/MITIGATED NEGATIVE DECLARATION MARCH 1011 FREDA STREET PIPE BRIDGES UPGRADE BAN LEANDRO. CALIFORNIA evaluations, the City of San Leandro has elected to replace the existing bell- and - spigot ductile iron sewer pipes with new ductile iron. restrained joint pipes that can accommodate the anticipated displacement of the pipelines for all design criteria. The existing pipelines would be removed and the new restrained joint pipes installed using a winch system stationed on the Alder Creek Circle side of the bridges. The new restrained joint pipe would be spaced to avoid interference with the structural members of the bridge. Installation of the ductile iron restrained joint pipes would require restraining the ends of the pipelines as they transition from the bridges to the buried pipeline sections. Poured -in -place concrete restraints. commonly referred to as deadmen, would be installed. Figure 3 shows the approximate location of the concrete restraints and other project elements, described below. In addition, a force - balanced Flex -Tend joint would be installed at the south abutment of each bridge, near Alder Creek Circle, to accommodate the anticipated longitudinal deflection of the pipelines. Installation of the deadmen would require extensive excavation, especially on the south side of the bridges near Alder Creek Circle. The deadmen would also serve as wingwalls to retain the soil upslope. An approximately 600 square foot area would be disturbed to excavate for the installation of the deadman on the south side of the bridges and an approximately 400 square foot area would be disturbed on the north side of the bridges. The excavation on the south side would extend approximately 6 -feet from the existing bridge abutments. while the excavation on the north side would be immediately adjacent to the existing abutments. In order to maintain sewer service, the pipelines would be replaced one at a time. Raw sewage from the pipeline under construction would be re- routed to the other pipeline during the construction period. Peak dry weather flow of both sewers combined is less than the capacity of either sewer pipe as measured in a 2008 monitoring study. No disruption of sewer service is expected during project implementation. All construction activities would be undertaken from the top of bank of San Leandro Creek. No work would be required within the creek itself. As described above, some excavation of the upper creek bank. particularly on the south side of the bridges. would be required to accommodate proposed improvements. Construction equipment would access the work area on the south side of San Leandro Creek via Alder Creek Circle and equipment staging would occur in the landscaped area between Alder Creek Circle and the bridges. Access to the north side of the creek would be via Alvarado Street and then over the railroad tracks. The access area on the north side of the rail tracks is mostly gravel. It is anticipated that a pickup truck and small bobcat would be needed for the construction activities on the north side of the bridges. Construction activities, including excavation for the deadmen, would require the removal of vegetation, consisting primarily of non - native species. and up to four native riparian trees, including an arroyo willow and three blue elderberry. The proposed project would implement Best Management Practices to avoid disturbance to San Leandro Creek. BMPs would include erosion control measures. including a wire reinforced silt fence and installation of construction fencing. In addition, a drop cloth would be suspended below the bridges during the bridge retrofit to prevent debris from falling into the creek channel. P: \EGI080110EQA\Preda_FINAL IS•MND.doc (0328/11) 3