The bio-augmentation solution
There are a lot of trees being planted in the name of cleaning up New Zealand’s lakes and streams. There are also chemicals like aluminium sulphate or alum being dumped into lakes to make them look clear, even if the by-product is a toxic sludge on the bottom.
A Waiheke woman believes councils and communities could do better by looking at what waterways do anyway to clean themselves up.
Claudine Kitson says bio-augmentation is widely used overseas, yet seems largely unknown in New Zealand.
She says the addition of bacterial additives to accelerate nutrient removal is one of the key approaches recommended by the North American Lake Management Association.
“I see instead a lot of work in various regions around reducing nutrient levels off farms through riparian planting and fencing off buffer zones between stand-off grounds and streams.
“There is also a lot of money being spent trying to sort out septic tanks, but it will take decades and it’s really hard to manage.”
That time lag is an issue with many forms of diffuse pollution, the effects of which can take decades to show up.
We don’t have the time, she says, with councils having to implement the National Policy Statement for Freshwater Management by 2025.
Her company Unblok (unblok.co) has taken an agency for Eco-Fix, which is a controlled release of micro-organisms) to break down contaminants.
She says it enhances the existing microbial community in the waterway, which makes the treatment method organic, safe and ecologically sustainable as well as being in tune with Maori cultural values on water management.
“It has been proven to work really well overseas and there are decades of results. “The other thing is it is really low cost,” Kitson says. She says a draft budget for treating the lagoon at Little Oneroa on Waiheke would be $2000 for an initial shock with maintenance of about $4000 a year to refresh monthly or after heavy rain.
Bio-augmentation can even be used in sewage systems.
The small Spanish town of Villalba de los Barros, injects bacteria into its sewer pipes to start the treatment process before the waste hits its treatment plant.
It has halved the sludge normally produced by the treatment plant and made the whole system better able to cope with the seasonal increase in activity during the peak processing season for grapes and olives, which producing a fivefold increase in wastewater.
“[Bio augmentation] has been proven to work really well overseas and there are decades of results”