The Hurunui District Council slashed wastewater screening costs at its Hanmer Springs Wastewater Treatment Plant by installing a one-of-a-kind, revolutionary product that uses no washwater, and discharges dry screenings.

With rising costs associated with the disposal of biohazardous waste, municipalities are pursuing cost-effective solutions to reduce the volume sent to landfill each year. Hurunui District Council saw considerable benefits and savings after implementing a Haigh ACE Screener to reduce wastewater screenings in its existing treatment plant at Hanmer Springs.

Revolutionising waste reduction

As the only product of its kind on the market, the Haigh ACE screen is capable of reducing the original screening volume by 94%. It is able to achieve this by macerating the incoming solids, dewatering and then compressing into a cake while returning the biomass back to the waste stream.

The final product is almost odourless and is so dry at 40% D.S. it is then able to be incinerated.

Previously, the Hurunui D.C. required 22 large 240L wheelie bins to store faecal-laden screenings destined for landfill, incurring significant expenses per tonne.

Now, the station discharges one 120L wheelie bin which only requires emptying every three months.

Low head loss

The ACE Screen’s minimal head loss of just 100mm is the lowest in its class with other screens typically 150mm-200mm headloss.

This alleviates issues in gravity networks, which are common throughout rural New Zealand.

No external washwater yields enormous savings

Unlike most wastewater screens, the Haigh ACE system uses no potable washwater nor re-use filtered washwater to wash the screenings. Instead it uses some of the influent to pump the macerated screenings liquor to the centrifuge/dewatering station which removes 98% of the biomass.

This innovation saves Hurunui D.C. a substantial 4,000,000 litres of potable washwater per annum at this single wastewater treatment plant.

With water treatment costs ever increasing and climate change resulting in longer periods of drought, it is important not to waste such a valuable natural resource.

Matt Dowdall, Project Manager Hurunui District Council, said, “This upgrade has undeniably been a pivotal step towards cost-saving and environmentally conscious practices. It’s shown how modern technology can lead us toward a cleaner and more sustainable future in wastewater treatment.”

Features & Benefits of the Haigh Ace Screen

• Only product of its kind on the market using perforated screen plate, macerator, centrifuge/liquid separator and compactor system resulting in high volume and mass reduction of screenings.
• Screenings reduced to 1/6th of other systems decreasing landfill demand and lowering carbon footprint.
• No external wash water required significantly easing water usage and preserving a natural resource.
• Control sequence minimises running time lowering power consumption providing an energy efficient solution.

Find out more about the Haigh Ace Screen here.