Have you heard about desludging?

As part of wastewater maintenance in Hurunui, every eight years or so the wastewater lagoons at our treatment plants are ‘desludged.’

This is some recent drone footage of lagoon dredging from Amberley wastewater pond near Amberley Beach, the collection point for Amberley Beach, Amberley, Leithfield Beach and Leithfield Village.

Lagoon dredging is by far the most common form of lagoon sludge removal, where the dredger floats on the lagoon and sucks up the organic and non-organic material (the sludge) from the base of the lagoon where it has settled. It is then pumped into perforated storage bags which are stored onsite in a contained bunded location (which you can see in this video).

A polymer is added which mixes with the sludge to assist with the drying process.

The bags will be held on site for the next two to three years, during which time the excess water seeps out into a sump and is pumped back into the pond.

The dried matter remaining in the bags can be re-used in different industries.