Worm wastewater system way to go at Huia

The thought might make many people squirm but one rural Waitakere community reckons it’s on to a winner with its new worm-operated onsite wastewater system.

When faced with replacing the system that served Huia Hall and the adjacent Settlers Museum, the Huia-Cornwallis Local Water Agenda Group (LWAG) recognised the no smell, no power and no discharge system had potential.

Enter Project Pipi – an initiative by the Local Water Agenda Group which includes representatives of the Huia-Cornwallis Residents and Ratepayers Association.
The community began operating the worm-operated system at the hall at the weekend (June 6) and plan to eventually link up the Settlers’ Museum. They believe the system has potential for anyone in rural communities.

“We are pretty typical of many rural coastal communities facing the dilemma of how best to deal with the problem of wastewater,” says Huia-Cornwallis Local Water Agenda Group (LWAG) chairperson, Denise Yates.

Many rural residents will have experienced the side-effects of on-site wastewater systems such as unpleasant odours, boggy lawns, blocked pipes and expensive maintenance.
Ms Yates says the group has worked closely with Waitakere City Council’s EcoWater team to get the project off the ground.

“They have been really supportive and enthusiastic, as was the Auckland Regional Council in the later stages of the project. This is a great example of council and community working together.”

The worm-based system is the invention of Coll Bell from the Matakana-based company, Simple Wastewater Solutions Ltd.

So how does it work?

Toilet waste is directed into the ‘wormerator’ - a two-metre long chamber in which tiger worms digest the solid matter, increasing or decreasing their population naturally to match the average incoming flow.
The liquid waste then joins the house grey water from the laundry and shower, or in the case of the Huia Hall, from the kitchen, before entering the second stage of treatment, the plant filters.
These boxed plants filter the treated effluent which then moves into the evaporator, a passive device using natural air flow to literally evaporate the treated outflow.

The system can be used for individual properties, groups of houses and public facilities such as the Huia Hall, which regularly houses events of around 100 people.
The other benefits of the system are that no excavation is required as the modules are all above ground and it only takes a few weeks to build and install.

Project Pipi was funded by The Trusts Charitable Foundation and Waitakere City Council, which covered the cost of consents and provided technical and project management resources.