Ensuring wastewater treatment plants operate efficiently and reliably is an important task that operational staff undertake.
In a move to recognise the excellent performance, initiative and attention to detail of operational staff, the Water Industry Operators Association (WIOA) has awarded its inaugural South Australian Operator of the Year Award to SA Water’s Hahndorf Wastewater Treatment Plant Operator, Daniel Partridge, for his work to reduce hazards and boost efficiency across several sites.
Mr Partridge has been with SA Water for eight years and works across several sites providing wastewater processing for communities around Murray Bridge, Mannum, Hahndorf, Stirling, Lobethal, Gumeracha and Angaston.
SA Water’s Senior Manager of Production and Treatment, Lisa Hannant, said winning this award was great recognition of Mr Partridge’s skills as an operator.
“Daniel is a high performer and his achievements have made a real difference to our business and customers throughout the Adelaide Hills and Murraylands,” Ms Hannant said.
“We’re fortunate at SA Water to have highly skilled, dedicated people working to provide vital services for communities throughout South Australia.”
Mr Partridge said it was a great achievement and honour to represent South Australia as the WIOA Water Industry Operator of the Year.
“Winning the award has given me an opportunity, which I otherwise wouldn’t have had, to learn from operators from all across Australia and New Zealand,” Mr Partridge said.
Reducing hazards and boosting efficiency
Mr Partridge was nominated by SA Water and competed against seven other South Australian operators to take out the honour for his work in reducing the number of hazards, and boosting efficiencies at wastewater treatment plants in the Adelaide Hills and at Murray Bridge.
He was prompted to make changes by SA Water’s safety culture program, Mate Watch, which is a behavioural based safety program that encourages employees to look for hazards/potential risks and come up with solutions. It also includes modelling good behaviour.
“When a suction hose attached to our Kelly & Lewis three-inch pump, was used to clean our contact tank, the grate had to be removed. I noticed that taking away this grate created a fall risk for employees into the 3m deep tank.
“I was keen to make this cleaning job safer, so I came up with the solution to adapt scaffolding to fit over the handrails around the tank. This eliminates the potential for an employee to fall into the tank when the grate is removed,” said Mr Partridge.
“The second hazard concerned the process for changing over the mixers in the bottom of our reactors. Employees at our plant were required to disconnect a cable holder from the top of a winch, around 2.4m off the ground.
“Due to the height of the winch, workers had to either use a ladder or step on the handrail to reach the cable holder, risking a fall. To fix this problem, I worked as part of a team and we decided to put in a piece of chain which lowered the cable clip.
“This made it easy to reach without a ladder or using the handrail, eliminating the fall risk for workers.”
Mr Partridge also wanted to improve efficiency, and identified a number of areas where changes could be made.
“Heathfield Wastewater Treatment Plant experienced higher than average inflows during the wet winter of 2016. Aluminium sulphate is used to remove phosphorous from wastewater, and at Heathfield we used flow-paced dosing of aluminium sulphate during highly variable flow periods,” he said.
“I identified an opportunity to improve efficiency within the aluminium sulphate dosing system, by changing from a flow-paced to a fixed dose system. This reduced chemical use at the plant. I also suggested using a larger front-end loader to transfer biosolids into our transport container – reducing the time taken for this task from one hour to just 15 minutes.”
Learning from facilities in New Zealand
As part of the award, Mr Partridge travelled to New Zealand in May where he attended the Wellness in Operations Conference in Queenstown, and visited local wastewater facilities to learn from their processes.
“Before visiting New Zealand, I hadn’t previously seen a wastewater process which dries out dewatered sludge from a centrifuge in a 100m-long glass house. When compared with conventional systems, this is really efficient taking the total solids yield from 20 per cent up to 85-95 per cent,” Mr Partridge said.
“It was interesting to see that a variable speed drive (VSD) can be incorporated into the pump motor on certain pumps to monitor torque. When torque increases due to ‘ragging up’ (i.e. a pump becoming clogged with non-flushable items) the VSD stops the pump, then reverses it to clear the blockage.”
Mr Partridge said he is also keen to improve how the turbidity wet rack lines at SA Water plants are managed, a process he was able to learn more about in New Zealand.
“A wet rack is where water is pumped to be analysed for turbidity – a key test for water quality. Fortunately as part of the tour we were able to visit a number of water and wastewater treatment plants which have wet racks to get ideas. I have taken details of several pumps that supply water to wet racks with a view to trialling some of these over the next few months,” he said.
“I also learned that the water catchment environment is quite different on New Zealand’s South Island compared to South Australia. In my home state, raw water from our catchment areas requires filtration barriers and treatment because it contains contaminants that enter the water from the environment. By contrast, some water processed at the South Island’s water treatment plants is pure enough to be pumped straight from the bore to the customer without any treatment.”
Selecting the right pump for the job
According to Mr Partridge, when it comes to choosing pumps for wastewater facilities, reliability, the right size and power efficiency are some of the key factors.
“Reliability is a key factor, and getting the right pump for the right job is a must. This involves making sure you have the correct size of pump and the pump has capacity to handle increased demand into the future. With many wastewater treatment plants looking to improve their carbon footprint and electricity costs on the rise, the power efficiency of pumps is also an important consideration,” Mr Partridge said.
“Energy efficiency of pumps is vitally important when deciding which pump to purchase. It’s possible to make major savings in energy costs just by selecting the right pump for the job. It also pays to pick a pump that has the extra capacity to only run during off-peak periods, or when the spot price for electricity is reasonable.”
Maintenance also plays an important role in ensuring pumps are running efficiently.
“We categorise our pumps into different levels of servicing depending on the value of the pump, the task of the pump, and the availability/reliability we require from the pump,” Mr Partridge said.
“Our pump categorisation system is important for our plant operations, because it allows us to tailor highly effective servicing schedules for our pumps and plan for pump replacement needs.
“I think it’s important for operators to develop an in-depth and current knowledge of pump products on the market. It’s vital to get the right pump that is durable and can achieve the required flows rates and pressures for the job you need it do.”