Record crane lift at SA Water's Bolivar treatment plant
The 115 tonne steel cover of one of SA Water’s Bolivar Wastewater Treatment Plant anaerobic digesters has been lifted with a 350 tonne mobile crane as part of a $4.7 million upgrade, setting a record as the largest crane lift in the utility’s history.
In no easy feat, Max Cranes worked with crews from SA Water and Fulton Hogan to guide the cover, 30 metres in diameter, to a temporary support system during the hour-long lift. Bolivar’s anaerobic digesters stand 14 metres high and have a capacity of 8.5 megalitres.
SA Water General Manager, Sustainable Infrastructure, Amanda Lewry said the successful crane lift was the culmination of 12 months of careful planning and assessment.
“Safety was at the forefront of this incredible feat and people might not be aware of the behind-the-scenes planning for the secure operation, which included compaction testing of the ground and an extensive bearing capacity assessment to help protect underground pipes,” she said.
“Eight heavy-duty slings were attached to fixing points pre-welded to the cover, while counterweights were used to stabilise the crane as it lifted our cover off the digester and atop the support structure.
“Our crews will now work on upgrading the cover during the next few months, including reinforcing the roof’s structure, installing a new insulation panelling system and cleaning the digester.”
Constructed in the 1960s, two of Bolivar’s six digesters will be upgraded to improve insulation of the covers, ensuring an optimal internal environment for the digestion process.
Lewry said the upgrades will also help to prevent escaping biogas, which is released during the metabolic processes inside the digesters, thereby creating a more renewable energy for the site.
“Upgrading our digesters enhances their ability to hold waste at a constant 38 degrees [Celsius] and creates an optimal environment for bacteria inside to help prevent the escape of biogas, a product we can reuse,” she said.
“Harnessing the power of biogas through our on-site gas engines creates a source of renewable energy for the treatment plant, which typically provides around 85% of the Bolivar facility’s energy needs.
“Biogas generation is an important part of our approach to energy management and by reducing and reusing waste, we are taking action as proactive environmental leaders to help enable a sustainable future.”
The renewable electricity generated through biogas at the Bolivar Wastewater Treatment Plant is enough to power around 4000 houses a year.