Construct retaining wall, MGS, cold plane & Pvmt widening.

Contract 04-3AA504 is a unit price basis solicitation issued by the California Department of Transportation for the repair and construction of a retaining wall on Marin State Route 1 near Muir Beach at Green Gulch. The scope of work includes the installation of a retaining wall measuring 337.33 feet long with a maximum height of 10 feet, utilizing HP10x57 soldier piles embedded 20 feet below the wall base. Additional project components include the replacement of culverts, guardrail installation, minor repaving, and the use of fiber reinforced matrix. The estimated total applicable project cost is 578,123.86 dollars. The project is subject to stringent environmental regulations and permits from the California Department of Fish and Wildlife, the US Fish and Wildlife Service, and the San Francisco Bay Regional Water Quality Control Board. Key restrictions include a mandatory work window for riparian habitat activities between June 1 and October 14 and prohibitions on nighttime concrete pours in wetted channels. Contractors must comply with Build America Buy America standards, Davis-Bacon Act labor requirements, and specific wage determinations for California. Bids must be submitted via the Bid Express website, with a final bid opening date of September 30, 2026. Performance is expected to begin within 55 days of contract approval, with a project timeline accounting for 130 time-related overhead working days.