Complete covers and floating covers for effluent ponds were compared and contrasted by DAFWA senior technical officer Hugh Payne in his presentation to attendees.

Mr Payne believes if pork producers cover their ponds, they will be well placed to face any Emissions Trading Scheme (ETS).

"Effluent ponds are a significant source of carbon and methane emissions," he said.

"New Zealand research suggests that covered ponds might be affordable for units as small as 2000 SPU, the benefits of covered anaerobic ponds is that they capture and store the potentially viable biogas which can be used as an energy source.

"They reduce the greenhouse emissions dramatically, and offer the potential for carbon credits."

A 1400 head sow breeding unit in Medina is currently enjoying the benefits of covered ponds.

Mr Payne said NZ research was used to design a system specific to the operation and a floating cover was constructed on a 30x35m site which covers 50 per cent of the pond.

A gas collection device was placed on the corner of the pond.

"This particular system collects about 65m3 per day of biogas, or about .05m3 of SPU per day, is equivalent to about 2000 megajoules per day, and is sufficient to replace the LPG currently used on the farm for heating the farrowing crates with enough left over to generate about 45kw hours of electricity per day," Mr Payne said.

"At the moment, gas is costing this particular farmer about $30,000 a year, and the electricity is worth about $1000.

"So if the cost all up was $134,000, you're looking at saving about $30,000 per year, so you can do the sums and work out that over five years it should've paid for itself."