Filtration system could hold answer to clean waterways

Ryan Boswell
Source: 1News

An experimental water filtration system could hold the answer to transforming our polluted waterways.

Christchurch-based Dr Ngārie Scartozzi has developed the eClean bioreactor, which uses microbes to remove contaminants from rivers, lakes and streams.

The freshwater scientist developed the technology over the last 15 years, after first designing holding tank filters at a fish farm in Australia.

She told 1News that she returned home to find her awa unswimmable.

Two-thirds of New Zealand’s freshwater rivers have been deemed ‘ecologically impaired’ by Land Air Water Aotearoa.

Scartozzi said water gets pumped into the container filled with bacteria to target different toxins.

“The first step is we analyse your water we figure out what your contaminants are and then we engineer the bacteria specific to the contaminants that are in your water.

“Each family eats out a different contaminant and through this process the water gets oxygenated.

“We remove a lot of the solids and we remove things like nitrates, phosphates, e-coli, heavy metals,” said Scartozzi.

Scartozzi has been trialling the system on part of Christchurch’s Ōtākaro Avon River, which has reduced half of all phosphates and e-coli that passes through it, and 85 per cent of nitrates.

“The goal is for it to be swimmable or wadable within 12 months.

“I wouldn’t recommend going swimming or drinking it at present … e-coli is in the thousands so to be drinkable or swimmable you need zero e-coli,” Scartozzi said.

The unit costs up to $80,000. Trials will take place on multiple sites this year, with local authorities analysing results before considering a further rollout.

Smart Christchurch Programme Manager Michael Healy said there was a lot of potential to use the eClean bioreactor on headwaters, wetlands and dairy farms.

“The bioreactor on its own isn’t a solution to urban waterway pollution but it could be part of the solution to returning the river to a healthier state,” Healy said.