An innovative wastewater treatment model – which is now part of the World Health Organisation’s sanitation safety planning initiative – has just won the SA Australian Water Association Infrastructure Project Innovation award.
Microbiologist Professor Howard Fallowfield says that sustainable purification of wastewater by naturally occurring algae is an outstanding way for regional towns to reuse precious water – and reduce their carbon footprint and power usage at the same time.
Professor Fallowfield from Flinders University was instrumental in designing and establishing high-rate algal ponds at Kingston-on-Murray and now Peterborough – which is the largest of its kind in Australia.
“Before the high-rate algal pond (HRAP) was built, all households and businesses in Peterborough disposed of their wastewater on site via septic tanks or disposal, which often resulted in raw sewage problems in people’s backyards,” Professor Fallowfield said.
Peterborough is similar to other small country towns. With a population of 1,500 people and located 250km north of Adelaide in the southern Flinders Ranges, water and power are costly to deliver.
The town’s two HRAPs, each 5000m2 in size and just 0.3-0.5m deep, were built with funding from the District Council of Peterborough, the SA Government Community Wastewater Management Scheme coordinated by the Local Government Association of SA, and the Australian Government through the National Stronger Regions Fund.
Professor Fallowfield believes the Peterborough system is a better solution for a low-energy carbon footprint, both during construction and operation, than conventional lagoon systems and regular electro-mechanical wastewater treatment plants.
In the large shallow ponds, wastewater is exposed to disinfecting sunlight to reduce pathogens while naturally occurring microalgae carries out its purification function.
“The reduced surface area and shorter retention time of HRAPs halves the evaporative losses, increasing the volume of treated wastewater available for reuse by communities in water-scarce regions like those in rural South Australia,” Professor Fallowfield said.
The wastewater treatment project has supported the expansion of the local feral camel abattoir in Peterborough. SAMEX has become a leading local employer, growing to 80 staff from 10 in 2012, including Indigenous employees and workers from the Ngaanyatjarra Camel company.
The benefits for public health of a sustainable centralised HRAP system has the potential to redefine the approach to wastewater treatment in rural communities around the world.
Researchers from the University of Nantes in France have already visited Peterborough to explore the opportunities for collaboration and application of the system to rural communities in France.
Long-running project supporter Colin Steele, Managing Director of Canberra-based consultancy Section 51, said the project is a fine example of university expertise teaming with government and other partners.
“The AWA award acknowledges that this project is a real and living example of a wastewater treatment project that incorporate sustainable design principles aimed at achieving social, economic and environmental outcomes,” Mr Steele said.
The project has gained international attention in recent years after Professor Fallowfield presented at a WHO/UNESCO workshop at the Bill and Melinda Gates Foundation, Seattle.
This led to the HRAP validation as a case study in the Global Water Pathogen Project, which is supporting global implementation of the WHO Sanitation Safety Planning Manual.
The Peterborough project is now in the running for the national AWA awards to be held in Adelaide in May 2020.