Overview
Ballard performed inspection and repairs of thirty-six- and fourty-eight-inch wood stave pipelines along the Columbia River in Washington.

Scope of Work
Ballard’s divers inspected the external surface of the outfall pipe and diffusers and used patching materials and wedges for sealing small holes. Ballard also installed new diffusers by attaching plates with a fixed riser to the wood stave pipe using new bands; stainless steel bands, shoes, and nuts; and installation and repair of ledger systems that suspend the wood stave pipe.

Additional project work, through multiple contracts, included intake cleanings, debris boom repairs, concrete pile repairs, pile cap repairs and placement, turning dolphins repair, and pile welding. Ballard has performed numerous inspections at the project site including the salt dock, outfall piping, intake screens, barge slip piling, and additional locations.

Innovative Solutions
Challenges that Ballard has faced at this project site include low visibility, high currents, floating debris fields, sediment buildup, and remote access. By utilizing slack tides to minimize river current during diving operations, Ballard was able to mitigate the high current challenge. Hydraulic chainsaws were used to mitigate and remove the woody debris.

Results
Ballard provided inspection services, video, and report documentation, as well as repairs safely and within the scheduled timeline.