Desalination and relentless ‘development’ for what? The sorry story of the SA Gulfs
There are three major desalination plants already functioning in Australia and a handful under construction or planning. This article raises some questions relevant to the healthy lives of DEA members and their patients in the coastal regions of most states.
Recently SA members of DEA visited the shore of Gulf St Vincent, south of Adelaide, to be briefed on the likely environmental and economic consequences of a soon to be completed desalination plant. Needless to say, we soon recognised many health impacts. The visit was organised by Ruth Trigg and Corrie Vanderhoek of the Save Our Gulfs Embassy, and River, Lakes and Coorong Action Group Inc. The tour was conducted by Dr Ian Dyson, a coastal and environmental geologist with thirty years experience along this stretch of coast. We thank all of themand we acknowledge the information provided below in the “Ten Reasons to save our Precious Gulfs” (Spencer and St Vincent). Now read on having taken your Prozac.
The coastline south of Adelaide reflects the sorry chronology of decisions made in ignorance of the ecological functioning of coastal lands and waters. These decisions have lead to loss of sea grasses due to storm water discharge and sewerage pollutions; loss of beaches from impairment of normal tidal and wave action by inappropriate groins and marinas and from residential development on land created by bulldozing foreshore land over the top of sand dunes. Collectively these changes threaten to viability of the Gulfs as breeding grounds for fish. Indeed, the Gulfs are marine zones of high plant and animal biodiversity – regarded by many experts as amongst the highest density in the world’s oceans. The desalination plant has been built in the middle of these degrading coastal lands and will surely accelerate the deterioration.
In October 2010, it was calculated that 100 GL of water from the River Murray cost around $8m. The cost of water from desalination is likely to be several times this. The cost of supplying the desalination plant with power was given by the plant management as $75m per year. That figure has been updated in 2011 to $130m. In terms of greenhouse emissions, it is stated that renewable energy sources will be created to cover this, but of course in the absence of the desalination plant, this creation of renewables would reduce the state’s emissions. This situation is just one cost of the mismanagement of the River Murray over several decades for Adelaide’s requirements from the Murray are around 200GL per year
Recognising the expected impacts on both Gulfs from climate change and from the population increases the State government is promoting and perhaps recognising that the universal fall in fish stocks will also impact SA, the government has produced a Bill to establish Marine Parks to protect breeding grounds. This has been met with fury by the recreational fishers, a fury reminiscent of that of the Murray River communities to the Murray Darling Basin Authority report in 2010. One can only be ashamed at the performance of our wealthy privileged country.
Unfortunately, this is not the end of the story, for the Olympic dam expansion cannot function without a desalination plant at the head of Spencer Gulf. This was opposed in the EIS (DEA included) but is likely to be imposed by the government. Its environmental impacts will be profound (see below).
Our visit to our own shore with local conservation groups indicated our common concerns over government failures to understand coastal and river ecology, and our concerns for a sustainable society in the face of plans for population growth and the powerful demands of the mining industry. All are fed by the unrelenting culture of eternal growth. We live in a state where health and environmental funding has been cut recently commensurate with a footy led recovery of the state economy with a government contribution of over $500m to redevelop Adelaide Oval, no doubt supported by the community.
The local indigenous groups, particularly the Njarrendjirri, have words for the connectivity of the environment and health, both collectively and individually; pity Western culture never developed them.
If I had to epitomise, in one word, society’s remorseless slide into unsustainability it would be desalination.
Web sites The website www.saveourgulfs.org.au will be operational from 25 April 2011.
I thank Ruth Trigg for her assistance in preparing this article.
Ten reasons to save our precious Gulfs
The extraordinary marine biodiversity of the Gulfs
The waters of Gulf St Vincent and Spencer Gulf are teeming with more species than in almost any other part of the world’s oceans. 80% of these species are unique to the Gulfs, whereas 80% of species of the Great Barrier Reef can be located elsewhere.
Researchers and photographers visit these gulfs from around the world.
Gulf St Vincent has around fifteen varieties of seagrasses, which, for thousands of years, have held the sandy sea floor in place. Before European settlement, stormwater was filtered in wetlands and marshes on the Adelaide Plain, especially in areas close to the coast.
Stormwater, chemical runoff and treated effluent entering Gulf St Vincent during the past
50–70 years have severely damaged the shallow marine environments. Stormwater needs to be held in wetlands for re-use.
This turbid stormwater mixture covers the seagrass close to the shore, limiting photosynthesis and eventually killing the grasses. The exposed sand is buffeted by the wave action and is moved along the coast from south to north. Many beaches are now exposed and degraded. Truckloads of sand are shifted each year to keep beaches available for public use and enjoyment. This costs millions of dollars every year.
Loss of marine life
The serious consequences of the loss of seagrasses and constant turbidity is a significant loss of plant and animal species, especially over the past 30 years. Being surrounded by the extensive variety and number of fish while snorkelling just offshore at the Port Noarlunga Reef is now an experience of the past.
Slow water movement in the Gulfs
Water flows into the Gulfs from a westerly entry, moves north, then down the eastern side. Due to the various depths of the gulfs these currents move at different speeds. A twice-monthly dodge tide, an unusual feature of the gulfs’ oceanography, means there is very little tidal movement for four to eight days each month.
Desalination produces a hypersaline brine and chemical mix
Sea water is cleaned of plant and animal material and put through membranes to separate the water and salt (reverse osmosis).
Concentrated residue (hypersaline brine) along with the chemicals used to clean the membranes is pumped into the sea 1.1km from the shore. The contamination of the hypersaline brine by the chemicals makes the mixture unusable in industry.
Hypersaline brine is sprayed through dispersers under the sea. Because the hypersaline brine is heavier than seawater it sinks to the bottom at times of dodge tides and slow currents. This causes lack of oxygen and marine organisms die in these conditions.
Fish nurseries are north of the desalination plant, and, as the young move into the Gulf research shows that fish eggs die when in contact with a small increase in salinity.
Dispersing hypersaline brine
Desalination plants in other places, such as the Arabian Gulf, and the coastline at Kwinana, south of Perth, have great difficulty dispersing hypersaline brine. The water movement in the Gulfs is much less than that along an open ocean. Will the ratio of 50:1 be changed to a lower ratio so that the companyrunning the desal plant can continue discharging hypersaline brine without being prosecuted?
Who will monitor the hypersaline dispersal rate and extent of the plume in the sea? What will happen if the salt density becomes too high? Will there be independent monitoring?
Post treatment of boron
Boron is a metal (metalloid) found in seawater. Boron scales the rust off pipes. The World Health Organisation (WHO) recommendation for safe levels of boron in desalinated water is less than 0.5 mg/L. Some chemical standards assert that there is no safe level of boron for humans. Desalinated water has to be treated especially to control the boron level and this greatly increases the amount of electricity used in the process.
Enough water — Murray-Darling Basin System, stormwater
The problem of the Murray-Darling Basin is caused by over-allocation—too much has been used and held back. Too often we are told that thedrought is the reason for the lack of water but Australia is a land of droughts.
Australia is also a land of floods. The 2010 floodwaters should now be flushing the system. Rivers die form the bottom up. This is our chance to flush Lakes Alexandrina and Albert, the Murray Mouth and the Coorong.
The River needs environmental flows to stay healthy. This year around 6 500 GL fell across the Basin. Adelaide needs less than 200 GL. The desalination plant is supposed to supply 100 GL. That amount of water can be bought from the system now for $8 million. It will cost around $130130 million a year for the electricity to supply the plant. Is this reasonable economics, especially if the demise of the biodiversity of the Gulf is part of the outcome?
Stormwater reclamation is another source of water for use. Instead, stormwater flows into the Gulf damaging the marine environment.
Questionable growth models
An increase in population of 560 000 in the next 20–30 years is SA government policy. It has taken over 170 years to reach 1.5 million in SA. Why the rush?
The desalination plant is justified on the grounds that it will supply water for this rapid increase in population. Is this an acceptable solution if it places the health of the Gulf under so much stress? (A desalination plant is also planned for Pt Lowly, near Whyalla, in Spencer Gulf.)
Once this ‘single solution’, a desalination plant, at enormous expense is installed, many other quieter, gentler, more sustainable solutions that enhance the environment and do not threaten it, are ignored. We are using a flawed model of ‘development’ for the future of the state: for the environment, for ourselves, for the future generations.
With careful planning, enough water can be sourced for Adelaide now, and for the future. A desalination plant on Gulf St Vincent is not needed.
Other growth models are possible
We are being given one model for growth—a developer’s model. Many citizens are not in favour of this model. It relies on claims that many dispute. We know we should plan for the future in a way that does not threaten ecosystems that have developed over millennia. We know we should not take prime land for farming and cover it with thousands of houses. We believe we can make progress by looking after and enhancing our rivers, wetlands, gulfs, land, and all the biodiversity depending on these living systems. A desalination plant in Gulf St Vincent or Spencer Gulf does not provide the necessary guarantees and confidence to proceed. We are the watchers and keepers, and we say NO. We choose to live with Nature, not against it. We act for present and future generations.
The desalination plant can be converted to a world-class marine research establishment, combining tourism and an Arts Centre. South Australia can lead the world by acknowledging its mistake and taking action by stopping the desalination plant before an entire Gulf system is destroyed. We have other time-tested technologies, such as the Salisbury Wetland model. We have other models for sustainable growth. Let that be our future.