A wastewater treatment plant at Bolivar which has been without its 118-tonne steel cover for 10 months has had the cover replaced better than ever according to SA Water.
Announcing that the $4.7 million upgrade of the plant’s anaerobic digesters were now in place, SA water said the 30-metre-diameter cover’s rehabilitation included reinforcing and recoating of the roof’s structure and installing a new insulation system to enhance biogas production.
According to SA Water’s Senior Manager of Capital Delivery, Peter Seltsikas the same 350-tonne crawler that removed the cover was one of the utility’s largest crane lifts which “sprung back into action” to replicate its earlier feat.
“After the cover was first craned off, it was carefully placed on 32 temporary concrete blocks surrounded with scaffolding to provide safe access for our teams to get to work rehabilitating the structure,” Mr Seltsikas said.
“Taking the cover off provided an opportunity to perform a thorough clean inside the digester to improve its holding capacity along with inspections of the structure and interior pipework to inform our future planning,” he said.
“Once the new steel plates were welded into place, we restored the cover’s internal insulation by injecting expanding insulating foam into small holes in the steel plates to help enhance optimal heat retention.”
He said that now the cover was back on, the SA Water team was focused on completing the external roof insulation and cladding system before it’s brought back online.
“This process will take around three months,” Mr Seltsikas said, “as we’ll need to get our bug colonies functioning by introducing ‘seed’ sludge to establish a strong population of bacteria that eat away at the new sludge to produce biogas.”
“Despite taking the digester offline for our upgrade, our Bolivar plant has reached record levels of renewable energy generation in recent months through our other five digesters and we’re hoping to reach new heights once they’re firing on all cylinders,” he said.
Mr Seltsikas said the digesters enabled a sustainable solution for treating the State’s ‘number ones and twos’ by converting them into a source of renewable energy while providing biosolids for use by local farmers.
