South Waikato District Council's Watermark Manager John Beale (who manages both our wastewater and water supply treatment plants) was given a top accolade - Winning Operator Paper - at the Water Industry Operators Group (WIOG) conference held in Taupo recently.
Mr Beale wrote and presented a paper entitled 'Centrifuge - 30 years of waiting, was it worth it?' to industry leaders and colleagues and earned the top prize, which means he is off to a similar conference of wastewater and water industry leaders in Australia in September, fully paid by the WIOG.
The paper was based on improvements to Council's own wastewater treatment plant in Tokoroa installed about 18 months ago. Previously Council used drying beds to remove moisture from wastewater sludge prior to disposal. The centrifuge that we installed for $870,000 is a mechanical dewatering system. The improvements and cost savings are impressive.
"The old system used to produce 10% of dry solid matter; the centrifuge system aimed to increase that to 20%," explained Mr Beale. "In reality, after operating the new system for 18 months, we are actually achieving more than that at 25% dry solids."
"We used to transfer around 1,000 tonnes of sludge to the landfill and this has been significantly reduced by half to 500 tonnes, which means that less product goes to landfill, extending its life," continued Mr Beale. "The process also involves fewer steps and less transportation of material further reducing operating costs."
Other improvements include a finished product that is far better for the environment and is now actually produces topsoil as the final cover for landfill; and wastewater sludge from all of the towns in the district can now be processed by the centrifuge in Tokoroa.
"We have retained some of the old drying beds that can be used in an emergency such as plant failure," said Mr Beale, "However in the 18 months since the new system came on line, we haven't had to use them at all."
An Australian delegation visited wastewater and water plants across the middle of the North Island during the week prior to the conference, including Council's fairly recent UV and microfiltration installation at the Blue Spring.
Mr Beale is looking forward to his trip to Melbourne/Victoria in September to attend the trade expo and conference there. "It is a huge opportunity to see wastewater and water supply plants and systems in Australia, new emerging technologies and listen to other experts in the field."
