Keeping the grey at bay

Peter Muirhead | VOLUME 25, ISSUE 1
A ten-berth houseboat can produce 1500 litres of greywater per day

The desperate plight of the River Murray due to record low inflows over the past few years is only too well documented, but not so what’s been going on behind the scenes to preserve and clean-up the water we do have and which we use for boating recreation.

In South Australia, the Environment Protection Authority (EPA) will soon begin enforcing new regulations aimed at improving the quality of the vast amount of so called ‘greywater’ that’s discharged from houseboats and other vessels on inland waterways.

It estimates that, with about two thousand vessels on the river in South Australia alone, hundreds of millions of litres of raw greywater is discharged into the river each year, impacting on water quality and posing significant environmental and health risks.

Greywater, as opposed to sewage or ‘blackwater’ – the discharge of which has been banned on the river in South Australia since 1976 – is waste-water produced from showers, washing machines, dishwashers and kitchen sinks. It gets pumped in from the river and then put back as a polluted mix of oils, detergents and a variety of solids from leftover meal scraps.

Figures from the EPA show that a ten-berth houseboat can produce 1500 litres of greywater per day – or 150 litres for every person on board. Under current regulations, this simply goes into the river untreated – in South Australia alone, the volume is put at up to half a billion litres annually – but that’s all about to change and a number of inventive Australians are set to benefit.


First to be required to comply with the new rules for treating or containing greywater will be newly constructed vessels, hire boats and permanent ‘live-a-boards’ from January, 2010. Owners of all other vessels will have another year. Houseboats and riverboats constructed from the beginning of 2009 – of which there have been just a handful, according to the EPA’s Pollution Avoidance Coordinator, Paul De Ionno – have already made provision to comply.

“We believe that what’s happened here with the degree of interest from several inventors is a result of regulation-driven innovation,” said De Ionno. “The EPA gave the option of treating the greywater rather than having to hold it on board and have it pumped out along with the blackwater. We’ve helped fund trials by several innovators from three states and now we have one commercially available greywater treatment system and a number of others which are well advanced.

“We also approached Standards Australia to establish an Australian Standard in greywater treatment and that’s now certain to be issued by the latter part of this year. Ultimately, we would like to see a range of systems come onto the market with a star rating from Standards Australia, giving consumers confidence in the products by promoting competition and quality.”

The first company to have an available system up and running is Newtreat Pty Ltd. Managing Director, Digby Mcleay says its ‘Super System’ has been many years in development.


“Our first prototype was invented ten years ago,” he explained. “Since then, and particularly over the past four years, we’ve been working hard to transform a great idea into a commercial product.

“Newtreat’s challenge has been to develop a system that offers long-term reliability, is easy to install and maintain, and is user-friendly and affordable. We believe the Newtreat Super System delivers on all of these.

“The way it works is that it captures all greywater in a tank and then sends it up to an on-deck treatment system. Our prototype was a flow-through-type arrangement, which couldn’t handle the peak demands resulting from many people showering one after the other in the morning, for example.”

Mcleay says development of its system has been assisted by grants totalling $120,000 from the Federal Government’s Commercialising Emerging Technologies Program or ‘COMET’. The company recently won the prestigious Water Industry Alliance – Innovation of the Year Award, sponsored by the Australian Water Association.

Another South Australian company is well advanced on its own system.

Houseboat Greywater Systems Pty Ltd will fit its unit to a luxury houseboat belonging to Shayne Quinn, who is co-inventor of the system with Adelaide-based Bill Holt. Once installed, it will undergo several weeks of rigorous testing by the EPA.

“Our unit comprises a 70-litre tank, which is mounted underneath from the deck beams,” explained Quinn.

Raw greywater is pumped into the tank and the solids of 100 micron and more, as well as the oil and grease, are separated out. The water is then pumped back into the river after passing through a series of filters, which lifts it to the standard required by the EPA.

The remaining sludge and solids, amounting to around six per cent of the total greywater content, are removed from the tank by a screw pump and deposited into the blackwater holding tank to be removed later at official pumping stations, says Quinn.

The company’s product development was recently recognised with an $80,000 Research and Development Grant from COMET.


The EPA’s Paul De Ionno says Victoria and NSW – the latter currently has a zero discharge law for vessels on both the Murray-Darling system and on Sydney Harbour – have been watching greywater developments, innovations and regulations in South Australia closely. He says there’s also considerable international interest from the USA, Canada, a number of European countries and also New Zealand.

“It’s potentially a huge market. There are two thousand houseboats on the River Murray in South Australia and in Victoria, for example, there are 700 on Lake Eildon alone.”

Victoria has been looking closely at South Australian greywater developments. Land and Water Management Officer for the Goulburn-Loddon Dams, Jeff Harrison says they’re going through the process of changing regulations to deal with greywater and are encouraged by developments regarding treatment.

“Containment is all very well, but with greywater representing something like ten times the volume of blackwater produced on a houseboat, there are issues with getting rid of it at pumping stations, which currently take only blackwater,” he says.

“First of all, there’s the time issue and secondly the impact this extra volume would have on the Goulburn Valley town sewage system. We’re looking forward to seeing the new Australian Standard released later this year.”

A spokesman for Maritime New South Wales says it is working with South Australia and other jurisdictions on the greywater issue and will consider any necessary changes, once the Australian Standard is published.

River boat owners are expected to be given some lee-way regarding enforcement of the new regulations.

“An example of this might be a houseboat that isn’t due for scheduled survey requiring it to be slipped for another few months beyond the start date of the new law. But we hope that, within three or so years, every boat will comply,” says Paul De Ionno.

In the marine environment, the Department of Transport in South Australia has begun surveying commercial vessels, including fishing boats and charter yachts, to new regulations gazetted in July 2008 requiring them to hold or treat all black and greywater.

Larger commercial vessels, such as South Australia’s sail training brigantine One and All have sophisticated systems that treat both black and greywater to a high standard before returning it to the ocean.

Under the current Code of Practice for Vessel and Facility Management, smaller craft, such as yachts and power boats, can discharge untreated greywater once they’re beyond one nautical mile of the coast, while untreated blackwater mustn’t be discharged closer than three nautical miles to the shore, aquaculture leases or any persons in the water.

If in doubt, it is worthwhile contacting the EPA or relevant marine bodies in your state for an update on current regulations. ¿

How to-Safety