A big stink

Experts and plant operators say Sydney’s sewerage system will not cope with projected population growth.

The NSW Government has predicted the number of Sydney households will reach almost 2.4 million by 2036, but Sydney Water’s already-struggling infrastructure only services 1.7 million homes.

Although the state’s Department of Planning and Infrastructure has developed a Metropolitan Strategy to cope with population growth, 60-70 percent of developments will occur in pre-existing urban areas.

As a result, pipes up to a century old – and designed for a significantly smaller population – will be forced to service the bulk of Sydney’s future sewage needs.

Brad Hazzard, Shadow Minister for Planning and Infrastructure, said it reflected a “cheap cop-out” by the State Government.

“If you’re adding substantial new development into already overburdened sewerage and water systems … then you have a problem,” he said.

“There are already too many sewerage overflow sites during wet-weather events, pipes break down, they crack … it’s an unsatisfactory arrangement.”

Dwindling State Government funding into sewerage systems has also affected local councils outside of Sydney Water’s service area.

Chris Carlon, Sewage Treatment Supervisor at Wingecarribbe Shire Council, said funding cutbacks had forced plant designers to cut costs by using cheaper products and leaving less room for population growth.

“You’re basically ending up with an inferior product at the end of the day because all anyone ever looks at any more is the bottom line.”

According to Mr Carlon, such cheaper materials needed to be replaced up to every five years – an expense smaller councils were struggling to meet.

“If populations grow quickly or if something changes … what they [some small councils] tend to do is just try and put band-aids on the plant and get it through, until they have a major upgrade,” he said.

Brendan Elliot, spokesperson for Sydney Water, said that the existing sewerage system coped “pretty well” with the existing population.

“We do factor future population projections … into our planning. We must do,” he said.

Under the State Government’s Metropolitan Strategy, 30-40 per cent of new developments will occur in the north-west and south-west of Sydney.

Mr Elliot said Sydney Water would plan for these developments where necessary.

“Our preference is to expand existing assets where possible and build new ones essentially as a last resort,” he said.

Sharon Beder, Environmental Professor at the University of Wollongong, said infrastructure capacity represented only half the problem.

Sydney’s sewers also act as the major toxic waste dump for most of the city’s industrial waste. According to Professor Beder, the treatment used for these chemicals had a negative impact on the environment.

“The actual treatment at the treatment plants isn’t adequate to protect the environment [and] adding increased flows will exacerbate the problem,” she said.

Mr Elliot said that while Sydney Water does treat industrial waste, all outflows were monitored and met the State Department of Environment and Climate Change’s specifications.

by Anna Watanabe