Sydney Water estimates that it could cost $7 billion to clean up Sydney's waterways, and as part of its corporatisation obligations it must end the dry-weather discharge of effluent to waterways. Friends of the Earth's JOHN DENLAY reports on how a coalition of environment groups has been helping Sydney Water with its planning.
When 240,000 people turned out at Bondi Beach in 1989 for a rally against beach pollution, it served notice on the Water Board (now Sydney Water) that the public wanted the problems fixed.
The board responded with the Ocean Waterways program — a $7 billion, 20-year program to restore water quality in Sydney. For the government to provide the money, the board had to demonstrate community support.
As part of canvassing community opinion, the board took the bold step of funding four peak environment groups to conduct independent studies into how Sydney can use water and manage waste water in an ecologically sustainable way.
The four groups — Friends of the Earth, the National Parks Association of NSW, the Total Environment Centre and the Nature Conservation Council of NSW — agreed to accept funding on the condition that they could maintain their independence.
The project
Under the name Sydney Water Project, the groups reviewed the state of Sydney's waterways. While they found improvements have been made, our waterways are still under stress. The project identified some key concerns:
- the unknown long-term effects of pumping minimally treated sewage into the oceans;
- rainfall entering cracked sewers during heavy rain can cause raw sewage to escape into waterways;
- sewage-related pollution in the Hawkesbury-Nepean River has left only those areas below the junction of the Colo River fit for swimming;
- the success of reducing phosphorus in effluent discharged to the river has not been matched with nitrogen, which is believed to promote downstream saltwater algal blooms; the impacts on rivers of other pollutants are not known;
- upper catchment dams have drastically altered flows in the Hawkesbury-Nepean — wetlands are not flooded as often, fish breeding and migration are inhibited and habitats are reduced;
- trade waste agreements have helped reduce industrial pollution, but little consideration has been given to reducing pollutants from households;
- while 70% of captured sewage sludge is put to beneficial uses such as composting, still only half of the available solids are captured at the coastal sewage treatment plants;
- half of the pollution load in waterways is due to stormwater;
- Sydney's dam-based water supply is vulnerable to drought. Last year the back-up supply on the Shoalhaven River ran dry.
In March 1994, the board released a discussion paper, Choices for Clean Waterways, outlining a range of waste water options.
Most options rely on receiving waters continuing to deal with wastes — despite uncertainties about the long-term impacts. One option, involving transferring effluent from Sydney's inland treatment plants to the coastal plants, would simply exchange river for ocean pollution.
In short, water would continue to be supplied from a distant dam, used once and then discharged, often with minimal treatment, to a waterway. Sydney has one of the most pipe-based water systems in the world, and it would not be surprising if the board favoured business-as-usual options.
However, reforms contained in the act and operating licence for the recently corporatised Sydney Water mean that it must break with past practices. The corporation must set targets for pollution reduction, water conservation and effluent reuse, and plan for environmental flows in inland waterways.
The most significant requirement is the phasing out of dry-weather effluent discharges to waterways. The NSW Environment Protection Authority (EPA) Board has indicated that planning should begin immediately.
Strategy
The Sydney Water Project has put together a strategy that will allow Sydney Water to achieve its new responsibilities.
Firstly, we need to stop wasting water. Sydney Water has used pricing to encourage water conservation, but it can do much more.
Sydney Water's new $10 million incentive scheme for water efficient devices, such as low-flow shower heads, is an important step. It was prompted by the project's findings that such schemes could reduce water use by 30% over 25 years.
Next, we need to reuse effluent. Sydney Water studies indicate that all non-drinking purposes such as industrial use, toilet flushing and irrigation would use only 7% of available effluent.
To reuse the quantities of effluent needed to end dry-weather discharges, the effluent must be highly treated to drinking standards and returned to the drinking water supply.
Highly treated water could be returned from treatment plants or sewer interceptor plants to local service reservoirs. In this way the supply of water could become decentralised throughout Sydney, breaking the heavy reliance on dams. This provides the key to drought-proofing Sydney and ending the need for future dams.
It could free dam water for "environmental releases" in inland waterways to mimic natural flows. The peak level of Warragamba Dam could be lowered, offering an alternative flood mitigation approach to the proposed raising of the dam wall.
When considering sewage treatment options, Sydney Water should choose treatment methods that ensure that the sludges produced are suitable for use in agriculture. Effluent and sludge quality can be further improved by Sydney Water by stepping up its programs for reducing pollutants entering the sewers.
When the Sydney Water Project took this strategy to a series of public meetings, it received overwhelming support. Decentralisation with extensive reuse was the preferred option for managing Sydney's waste water.
The Sydney Water Project has published its findings in nine detailed issues papers and a 150-page final report.