Ageing treatment plant gets a makeover

Thirty minutes north of the Sydney CBD, fringed by the Ku-ring-gai Chase National Park, you will find the Terrey Hills Golf and Country Club. A former quarry site, the club opened in 1994 and is today renowned for its natural bushland and close proximity to the city.

The course’s superintendent, Stuart Gill, noted that the club is “committed to environmental best practices and caring for our natural assets, which includes treating our wastewater on-site for re-use on the course”. So when the club realised that its ageing wastewater treatment plant was underperforming, it knew it had two options: build an entirely new plant or upgrade the existing one.

After reviewing a variety of technology platforms, the club decided to retrofit BioGill above-ground bioreactors to the existing plant. Developed by the Australian Government, BioGill technology is based on the premise of harnessing nature.

Nano ceramic media, known as ‘gills’, provide an oxygen-rich habitat for microorganisms, enabling them to grow and flourish. This increases nutrient removal from wastewater, resulting in high-level reductions of BOD, COD and organics.

The plant uses six BioGill Towers and four custom-made submerged modules to treat 40,000 L/day of sewage from a residential estate and wastewater from the restaurant kitchen and toilets at the club. The treated wastewater is then re-used for subsurface irrigation within the estate.

“One of the main advantages, from my point of view, is that the BioGill system has reduced the levels of nitrogen coming into our irrigation water,” said Gill. “Previously, we had a high nitrogen water source which played a major role in delivering more nitrogen to our turf surfaces without our control, causing a variety of playability and turf health issues, including puffy turf that is prone to mower scalping.”

The plant is now fully compliant, with independent testing showing total nitrogen reduced from 40 mg/L to less than 8 mg/L, total BOD reductions from 340 mg/L to less than 10 mg/L and soluble BOD in the effluent reduced to undetectable levels. The plant is meeting all the treatment requirements from the local authorities.

“Our makeover approach has saved the club money, increased the treatment performance and extended the life of the existing plant,” said Gill.

Image caption: The BioGill treatment plant at the golf course.