Sydney's deepwater sewage outfall has reversed Bondi's reputation as one of the nation's dirtiest beaches.

Across Australia locals and green groups oppose sewage outfalls, but are they as bad as detractors make out? Sara Phillips reports.

"It's a dirty, dirty business," says Peter Smith, president of the Clean Ocean Foundation, before launch-ing another attack on Melbourne Water and EPA Victoria. Smith's group has taken the EPA to the Victorian Supreme Court to prevent the proposed extension of the sewage outfall pipeline on Melbourne's Mornington Peninsula.

Greg Hunt, the federal MP for the area, is also pushing for the eventual closure of the outfall. Even David Fox of CSIRO, project director of the effluent management study for the outfall, told WME the approach was short-sighted.

Similar stories are repeated across Australia, with local and green groups protesting about polluting the ocean with our liquid waste. But if sewage outfalls are as bad as the environmental and community groups make out why are they still used? How damaging are they?

Chris Davis, executive director of the Australian Water Association, says outfalls are OK if properly designed, but a lot depends on the sensitivity of the receiving environment. Impacts can vary from nil to significant.

The nation's hottest battle over ocean outfalls was fought in Sydney through the 1980s, resulting in the old cliff-face pipes being extended 4km out to sea, into 50m of water. While the sting has gone out of the debate with the deepwater outfalls from the North Head, Bondi and Malabar treatment plants, environment groups still oppose the practice.

Michael Ray, senior policy officer for business and industry with the WWF, is scathing about Sydney's treatment of effluent, describing it as "basically sieving out anything larger than a Volkswagen." It is true that the high-rate primary treatment Sydney Water employs is the bare minimum.

However, the deepwater outfalls have proven positive, both for inshore and offshore water quality. Recent NSW Department of Environment and Conservation (formerly NSW EPA) tests have shown the city's beaches have the lowest bacteria levels in a decade.

"For the first time in history it would appear the deepwater ocean outfall has no particular local environmental impact," adds environment protection officer John Dengate.

He cites a five-year, $21 million study, which found some observable impacts of the new pipelines but not so great as to cause concern about the effects on human or environmental health.

Neil Lazarow, national projects director for the Surfriders Foundation and lecturer in coastal management at Griffith University, says Sydney has been "pretty lucky". The deep ocean floor, temperate waters and strong East Australia Current dilute the pollution before too much harm is caused.

"From a human perspective they've done pretty well. The trouble is humans aren't the only creatures that use the sea," he said.

EXTENDING THE PIPELINE
The major confrontation over outfalls has moved to Melbourne, despite it faring a little better than other cities. It has two main sewage outfalls, one from the Western treatment plant at Werribee into Port Phillip Bay and one from the Eastern treatment plant into Bass Strait. Each currently releases secondary treated effluent.

Melbourne Water has spent considerable funds investigating the impacts of its outfalls. Despite the Werribee plant emptying into a bay carpeted in famously pollution-sensitive sea-grass, a $12 million Port Phillip Bay Environ-mental Study completed in 1996 found it had minimal impacts, none of which were detectable more than 500m from the outfall.

The eastern treatment plant is the focus of complaint. It has a significantly greater effect, with investigations by the CSIRO recommending a reduction in discharge volume and ammonia levels to prevent the further demise of the so-called "Neptune's necklace" seaweed, Hormosira banksii. Melbourne Water has begun a $170 million upgrade, including denitrification works to reduce the ammonia levels. It also proposed to upgrade to tertiary treatment and, at the behest of EPA Victoria, extend the outfall pipeline 1.5km out to sea.

It is this last aspect that Smith and the Clean Ocean Foundation object to. He says if the outfall is extended the government will forget about trying to put the water to better use.

Flinders MP Greg Hunt acknowledges "you can't just put a cork in it," so he wants to see the water reused. After the tertiary upgrade he wants to see the water piped to the industrial area of the La Trobe Valley - a distance not that much greater than the current 56km pipeline from Melbourne to Bass Strait - and eventually hopes it will reuse all of the wastewater, some 400ML per day. CSIRO is assessing the financial, environmental and social impacts of the proposal.

WHY NOT REUSE THE WATER
Reuse is the catchcry of all outfall opponents. WWF would like to see effluent upgraded and reused, with Ray calling for tertiary treatment in Sydney, "at the very least". CSIRO's David Fox believes the deepwater outfall at Melbourne is second best.

"The footprint [of environmental impacts from the outfall] is small, especially given the size of the population it's servicing. But it doesn't mean to say we can't to better," he says. "It's old engineering technology. It doesn't take us any further down the sustainability path."

Water authorities broadly agree. Melbourne Water plans for 20 per cent reuse by 2010 and says it has identified a number of potential uses for the water, including turf-farms, market gardens, vineyards, golf courses and "third-pipe" solutions, as in the Sandhurst estate.

"Reuse is our long-term aim for sewage disposal in general," says the DEC's Dengate, "but at the moment the economics are just not there."

On the NSW north coast, however, Coffs Harbour City Council has bitten the bullet. It is spending $170 million sewering its community, building a new treatment plant and upgrading others to tertiary standard in its goal to reuse 100 per cent reuse of its effluent.

The plan has come to fruition after 20 years of community discussions. Earlier outfall suggestions were repeatedly knocked back by the locals, who feared the impacts on their beaches. Now a chronic water shortage has provided the final impetus for a reuse scheme.

It still includes an ocean outfall, but only as a release valve for when demand for the recycled water falls below the supply, such as during wet weather.

Michael Ray is cautious in his praise: "If they achieve 100 per cent reuse that's terrific. You'd have to acknowledge a redundancy in the system at times, but it sounds like a better system than many others around Australia."