A solid separator is a machine that removes solids from the effluent collected from piggery pens and dairy milking sheds. It uses screens, mechanical screws, gravity settling or rotating drums to squeeze moisture out of the solids. The result is less sludge in your pond, drier solids that are easier to handle, and a cleaner liquid that is easier to pump.

Removing solids before they settle reduces pond and lagoon build-up, so you need to desludge less often. It also cuts odour, because composted solids break down with less odour than raw slurry sitting in a pond. Separation reduces methane from effluent ponds too, and new separation projects may earn Australian Carbon Credit Units.

The three most common types are weeping walls, screw presses and incline screens. A weeping wall drains liquid through a slotted wall. A screw press uses a rotating auger to squeeze effluent through a perforated screen. An incline screen lets liquid pass through a sloped screen while the solids slide off. Centrifuges and inoculants, which are additives that help solids separate, are other options.

The right separator depends on your effluent volume, budget and how much maintenance you want to take on. Weeping walls are the simplest and lowest cost. Incline screens are non-mechanical, simple and cheap. Screw presses are mechanical and compact the solids as they separate them. Ag2Energy partners with equipment providers and can help you find the right fit.

Separated solids need to be composted, either in windrows or in stockpiles. Windrows are long piles that are turned occasionally for aeration. Composting is an aerobic process, which is what allows solid separation projects to avoid methane emissions.

Yes. Under the Animal Effluent Management method, piggeries and dairies can earn Australian Carbon Credit Units (ACCUs). To qualify, the farm removes solids from effluent that would otherwise go to an anaerobic pond and treats them aerobically, for example by composting.

Your effluent must come from a piggery or dairy and would otherwise have gone to an anaerobic pond. The separation facility generally needs to be new. An existing separator can only qualify if it wasn't used in the three years before you apply and hasn't been used since 1 January 2019. Contact Ag2Energy to check your farm.

You may still be eligible to generate ACCUs going forwards, please get in touch so we can discuss your options.