Hilo WWTP Outfall Repairs
This project consisted of repairing several existing leaks and an undermined section of the 48” Hilo WWTP outfall pipeline, at an approximate 50’ depth. The leak repair portion of this work consisted of several methodologies, including the use of oakum, epoxy grout, large stainless steel pipe clamps, and grout jackets. Repairing the undermined portion of the outfall pipe required excavation, placement of filter fabric, and the placement and pouring of several layers of concrete fabric form bags and mats. The final design of the fabric forms and the concrete mix design were completed by AMC. AMC utilized specialized charter vessels and concrete mixing and pumping equipment to set up an offshore batch plant, and pump concrete to a depth of 50’. AMC was able to overcome challenges with concrete material logistics, bad weather, and stringent BMP requirements to complete the project.