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that approximately 78 steel piles would be driven into the slough bottom (Chen, 2005). The contractor would extract the piles and remove the trestle after the bridge had been constructed. Under the Bridge #2 Trestle Alternative, the piers for the bridge would be transported to the project site and would be driven into place by a crane parked on the trestle. The truss segments of the bridge would also be trucked to the site. The bridge pieces would then be lifted into place using the crane on the trestle. Access for large construction equipment may be limited on the north embankment due to the narrow and small radius curves of the existing access road from the city of San Leandro Water Pollution Control Plant. Bay Trail Connection Alternatives Several alternatives for the trail connection have been considered (Table 1). The design engineer considered five separate alternative alignments and construction techniques for the trail, three of which involve widening the existing 13.5-foot (4.1-meter) wide levee maintenance road to accommodate the trail (Mark Thomas & Co., 2004a). Alternatives #3, #4, and #5 have been rejected. The Preferred Trail Alternative is Alternative #1 Retaining Structure (port of Oakland side). Under this alternative, a retaining wall and fill would be placed on the slope of the levee on the Port of Oakland (north) side of the existing levee (Figure 5). This alternative would require approval by the Port since it involves Port property. A draft Right-of-Entry and Indemnity Agreement between the Port and the City provides for Port maintenance and repair ofthat portion of the trail on Port property beginning 12 months after construction. The retaining structure would consist of24-inch (0.6-meter) cast-in-drilled-hole (CIDH) steel soldier piles with a treated timber lagging wall of 4-inch by 12-inch (OJ-meter by O.3-meter) Douglas fir or redwood placed horizontally. The piers would be driven between 6 (1.8 meters) and 20 feet (6.0 meters) deep from the top of the levee, lagging installed, and then four feet of lightweight fill would be placed on the existing slope to widen the top of the levee and create the trail surface. The retaining structure and fill would be placed outside ofthe wetlands area, which begins at the toe of the levee. New fencing would be installed to separate the existing levee maintenance road used by the city of San Leandro trucks from the new traiL The trail would be constructed as a 10-foot (3. I-meter) trail with 2-foot (0.6-meter) shoulders, which meets the San Francisco Bay Trail standards. Under Alternative #2 Mixed Use Trail/Road, the maintenance trucks and pedestrianslbicyclists would share an 11.5-foot (3.5-meter) wide trail with one-foot (O.3-meter) wide shoulders (Figure 6). A removable or fold-down railing would be installed to prohibit public access to the sediment ponds. Two electric gates would be installed to separate the trail from the remainder of the maintenance road that encircles the pond. This alternative would require the trail traffic to co-mingle with the City wastewater treatment plant maintenance activities at the sediment pond, and additional effort would be required to remove the railing to maintain the ponds. Alternatives Considered and Withdrawn Three alternatives related to the trail connection have been considered and withdrawn (Table 1). Y4204lS.Q0693.doc - 4/5/07 -5-