AZ&B provided design services for the replacement of approximately 4,350 linear feet of existing 10”-12” wastewater main with a new 18” PVC wastewater main. The existing wastewater line was located in an eroded creek channel, and the sewer pipe had minimal coverage and was exposed at some locations. AZ&B replaced the existing main with an 18” PVC wastewater main at a flatter slope to provide additional cover above the top of pipe. Concrete encasement was provided around the pipe within the creek channel. For the first 1100’, the wastewater line was relocated outside the banks of the creek, but construction was still close enough to the channel that the right bank had to be reconstructed with rock gabions. The relocated sewer line was also close to ONCOR’s steel towers for high voltage transmission lines, and it was constructed by bore next to the towers’ concrete foundations. The remainder of the project was constructed in the creek channel, and the trench was backfilled with cement stabilized sand.
- Wastewater Design