Legislative Council Fifty-First Parliament, Third Session (51-3) 51 3 Parliament of South Australia Legislative Council published Parliamentary Committees Environment, Resources and Development Committee: Desalination Plants ENVIRONMENT, RESOURCES AND DEVELOPMENT COMMITTEE: DESALINATION PLANTS The Hon. R.P. WORTLEY Legislative Council The Hon. R.P. WORTLEY (16:44): I move: That the interim report of the committee be noted. The Environment, Resources and Development Committee commenced this inquiry into the environmental impacts of the proposed desalination plants at Port Stanvac and Port Bonython in August 2008. As part of the inquiry, 37 submissions were received and 11 witnesses were heard. Submissions and witnesses included key players from state and local government, industries, academics, non-government organisations and community groups, providing a cross-section of views, ideas and information on environmental issues arising from the proposed development of the desalination plants at Port Stanvac and Port Bonython. Due to the release of the environmental impact statement by SA Water for the proposed plant at Port Stanvac, this is an interim report focusing on impacts in Gulf St Vincent. Further comment on Gulf St Vincent may be included in the final report. Our knowledge of environmental impacts from desalination is largely based on limited research from relatively small plants operating in relative isolation from each other across the globe. Cumulative impacts, both over time and including other inputs in a particular region, are only now beginning to be investigated. Complicating our lack of knowledge here in South Australia are the site specific conditions of building a large scale desalination plant in an inverse estuary, where the lack of adequate circulation could amplify impacts on the marine ecosystems. It is this factor, whereby the desalination plants are being built in inverse estuaries, which caused the most concern for members of the committee. None of the submissions received or any of the witnesses that appeared were totally opposed to desalination per se, but they were concerned with the issue of adequate dispersal conditions on Gulf St Vincent, and many suggested alternative siting. The release of the environmental impact statement by SA Water addressed a number of design questions raised during the inquiry. The construction design of the full tunnel option appears to provide the method of least environmental damage and intrusion into the marine environment. Strategies have been designed to prevent the impingement of marine organisms. The only strategy to prevent entrainment of larvae, eggs and plankton is the use of low speed intake. Backwash sludge will be dewatered and disposed of on land, and modelling has been used to design the diffuser system to ensure that dispersion of brine will occur efficiently. The committee believes that desalination can be a beneficial technology if established and used in a sustainable and environmentally aware way. Due to the paucity of information, the committee has concerns regarding the dispersive behaviour of the brine stream during the twice-monthly event of dodge tides and recommends stringent monitoring take place during these periods to obtain actual live data to validate the modelling that has been used as the basis for the current plant design. The committee is also of the opinion that all monitoring regimes should be designed to include provision for measuring cumulative impacts, as Gulf St Vincent is already considerably impacted by industrial, stormwater and waste water discharges. Given the likely increase in interest in desalination plants, the committee also believes that reforms are needed to environmental legislation and policies to ensure that proponents have clear directions as to appropriate locations and the operation of future desalination plants in South Australia. The final report will be completed in 2009, following the release of the environmental impact statement for Spencer Gulf by BHP Billiton. I commend the report to the council. Debate adjourned on motion of Hon. T.J. Stephens.