OPEC Subsea was engaged by BMD Constructions to install new water intake infrastructure for the Teddington Weir water treatment plant which provides drinking water to the town of Maryborough in Queensland.
The works included installation of environmental controls to protect the quality of the water supply during works. This was followed by a detailed seabed survey to identify obstructions and layout the location of the structures. The divers then conducted excavation of the site with all material captured inside silt curtains. Steel work was then transferred to the water using a 200 tonne crane. Due to the limited access on site these structures could not be directly placed by the crane and as a result OPEC deployed four purpose-designed and engineered lifting pontoons to transfer the two structures weighing 5.8T and 8.3T respectively to their final location. Once location and level were confirmed by a surveyor the baseplates were filled with concrete. OPEC sealed the form work to contain the concrete and ensure no contamination of the river. 250m of pipe from 710mm to 50mm in diameter was then fitted and torqued to specifications. Finally the entire site was covered with rock and secured with an Erosion Control Solutions 200mm flexiblock grout filled mattress covering around 780 square metres.
The works showcased OPEC’s ability to solve challenging marine construction problems whilst maintaining the highest levels of environmental controls.