Reporoa based Murdoch Agricultural Contracting, owned and operated by couple Harry Murdoch and Samantha Parker, started by targeting a niche.
The result is a homogenous mix that cna be moved efficiently by effluent pumps or vacuum tankers.
Built extensively from high-grade galvanised steel, the design features a triangular pedestal that is bolted to a concrete pad at the edge of the pond. Cleverly, the unit is supplied with pre-formed ground anchor boxing forms of a 2 cubic metre capacity, needing a flat level site and the obligatory load of around 5 tonnes concrete.
A deep, square-section support tube, of 10 metre or 12.5 metre length, carries a large propeller, surrounded by a heavy-duty shroud, not unlike an empty oil drum with sloping sides. The interaction between the propeller and the shroud is designed to increase the velocity of the liquid, while at the same time creating a vortex that keeps solids in suspension, and helps reduce the build-up of silted areas within the pond.
Depth control and operating angle is achieved using an integral foot at the business-end of the machine, alongside a chain/racket system at the pedestal. As part of the design, the impellor is driven by a 4 or 7.5kW motor housed in a fully sealed unit at the working end, removing the need for a complicated driveline associated with shore-mounted power plants.
The manufacturer suggests that the ease of installation, combined with superior performance and minimal servicing requirements, makes effluent agitation a cost-effective solution on most farms given the $15,000 - $20,000 price tag, depending on specification.