We've always known our people will go to any depths to get the job done, and in the case of BHP’s Olympic Dam, our highly skilled diving team are no exception.
Olympic Dam is a large underground mine located in far north South Australia, around 560 kilometres north-west of Adelaide. It’s the fourth largest copper deposit and the largest known single deposit of uranium in the world.
Water performs a critical function at Olympic Dam, where it is used for a variety of purposes, including drinking, showering, and washing, as well as water that is used within miningand smelting processes.
For these reasons, BHP maintains numerous water storage and water treatment facilities.
Most of the water used at Olympic Dam is sourced from the Great Artesian Basin (GAB), a resource shared with local Aboriginal communities, communities, agriculture, and other industries. The GAB is the largest groundwater basin in Australia, covering more than 1.7 million square kilometres across Queensland, New South Wales, South Australia and the Northern Territory.
Effective and appropriate water stewardship at Olympic Dam is not only essential to the mine’s operation, but for its long-term sustainability and contribution to social value. For these reasons, BHP inspects its water storages on an annual basis, assessing all components for potential defects that could affect the supply of water to 4000 plus personnel,its operations and the local communities.
For the pastfew years, BHP has engaged Water Engineering Technologies’ (WET) commercial dive team to conduct comprehensive visual inspections of its 2.5 megalitre (ML) bore field, 10 ML, 60 ML, 80 ML, 120 ML, 170 ML and 200 ML water storage facilities.
The inspections are conducted by our professional Australian Accredited divers (ADAS) who spend many hours each day submerged underwater while they thoroughly inspect these essential assets for liner defects, foreign debris and the condition of inlet/outlet structures.
Due to the remoteness and isolation of the high-risk work being performed, the WET dive team must formulate a plan that accounts for any foreseeable emergencies resulting from the diving operations such as decompression illness. The divers also regularly undertake training and drills to maintain their specialised skills and Work Health Safety (WHS) risk awareness and responsiveness. When safer or more effective to do so, our team instead use a robotic operated vehicle (ROV).
WET Chief Diving Officer Spencer Franko said, “Our team performs a great range of underwater construction and maintenance work to depths of 30 metres. This includes the maintenance of SA Water assets, such as the 900 water storage facilities that need to be inspected every five years.”
Success is in the planning
In June 2020, WET mobilised its highly skilled diving team and extensive inventory of plant and equipment in preparation for the start of this year’s diving operations at Olympic Dam.
Our dive team, comprising Chief Diving Officer Spencer Franko and our commercial divers Jamie McGregor and Matia Taito, formulated a comprehensive dive plan, risk assessment, and emergency response plan to ensure that they could, once again, safely and efficiently complete these operations on time and within budget.
From the most important life support equipment to the simplest of tools, maintaining safety and quality is of the highest regard. For these reasons, our air diving unit comprising a breathing gas, air distribution panel, breathing umbilicals and diving helmets. The equipment exceeds industry practices and are compliant with AS/NZS2299.1.2015 and AS2815.2 diving standards.
Together with BHP representatives, our team performed a pre-dive meeting to review and approve the dive plan and ensure that all safety measures had been considered. These included isolating pumping systems and the closing of outlet valves, and assessing access and egress methods.. Once the water storages were fully isolated, BHP representatives were notified and diving operations commenced.
Regular diver rotations were maintained to limit the effect of environmental exposures, such as heat and cold stress.
The divers conducted visual inspections of BHP assets while capturing photographic evidence of their condition. These included the divers following liner welds systematically to check the condition of seams and also inspecting all areas of the liner reporting on visual defects, blistering, foreign debris, fabric off cuts, depth of any sediments and the condition of inlet/ outlet structures.
In total, the dive team spent a significant time underwater, diving to a maximum depth of nine metres. Albeit this was an extended bottom time, the divers alternated shifts so that the dive time was well within acceptable limits.
Matia Taito conducting inspection of the 200ML process water storage.
Matia Tatio (diver) and Jamie McGregor (tender) conducting an inspection of the Roxby Downs 10ML Potable water wet well.
Damian Sturm supervising diving operations.