Minor Alteration No. WA2025065 – Oxbow Marina Sanitation Facility Infrastructure Repair Project

To perform emergency repair to the sewer line in Oxbow Marina. The sanitation facility infrastructure including the forced sewer main was permitted under Board Permit No. 4398 which was issued in 1973. Potholing of the levee was conducted to locate and determine the extent of damage to the sewer main. Condition assessment of the pipe was performed to evaluate whether a repair or full-in-kind replacement was necessary. The investigation revealed that the existing forced sewer main had been compromised by an unknown source. Emergency repairs were executed based on the assessment findings. The compromised coupler was replaced in-kind by welding a new coupler at the identified location. Excavation backfill was completed using controlled low-strength material through the levee crown, or native material along the slope and toe of the levee, depending on the final position of the repair. Site restoration was performed to return the area to pre-existing conditions, including roadway repaving and the replacement of any features disturbed during the investigation and repair work.