Question Time

STORMWATER HARVESTING

Mrs REDMOND (Heysen—Leader of the Opposition) (14:15): My question is to the Minister for Water Security. Does the minister stand by her statement on radio this morning that the science is not there for use of stormwater for drinking purposes? On radio this morning the minister claimed that the science is not there for the use of stormwater for drinking purposes. However, re-use of stormwater has been successfully implemented in the United States, Europe and Singapore over at least 40 years. Singapore has four water recycling plants. The Queensland government's western corridor recycled water project has the capacity to produce 182 megalitres per day of recycled water for industrial and potable purposes, including supplementation of their major dam; and, in New South Wales, Orange is already using stormwater for drinking water. They clearly think the science is there.

The Hon. K.A. MAYWALD (Chaffey—Minister for the River Murray, Minister for Water Security) (14:16): I welcome the first question from the Leader of the Opposition.

Members interjecting:

The SPEAKER: Order! The Minister for Water Security has the call.

The Hon. K.A. MAYWALD: As I was saying, I very much welcome this question from the Leader of the Opposition and I welcome her formally to her position as the first woman 'major' leader of a party in this state, given that for 12 years I have been leader of the National Party. I just thought I would make sure that was on the record.

An honourable member: You are the first woman leader to be a minister, though, aren't you?

The Hon. K.A. MAYWALD: I am the first woman leader to be a minister, and I am very pleased to be in this role.

In relation to the question asked, I point out that there is a very big difference between treated stormwater being put directly into the drinking water supply and treated water being put into what they call an IPR, which is a non-direct way of putting into the potable system—in other words, going through an alternate route.

The South Australian government feels the science that has been undertaken to date does not give us confidence that we can put treated stormwater directly into our drinking water, and we would not do it. We would not put at risk South Australians' health on the basis of putting road water, no matter to what level it is treated, into the stormwater because the science does not give us confidence that all risks can be mitigated.

Members interjecting:

The SPEAKER: Order!

The Hon. K.A. MAYWALD: Secondly, the issue of rainwater and stormwater depends largely on where that rainwater and stormwater falls, where it is captured (as to what the quality of that water is) and what the costs are associated with treating it. The science tells us that, in areas where you have great dilution capacity and the dilution component of those contaminants is small, then it is much easier to treat. But when you are running off a major capital city—even the Salisbury council is not seeking to put it into the drinking water supply. The Salisbury council, Colin Pitman—shall I quote from this morning—

Members interjecting:

The SPEAKER: Order!

The Hon. K.A. MAYWALD: Can I speak directly to a comment that was made by Colin Pitman this morning on ABC 891, when asked by David Bevan, 'Should we seriously be thinking about using stormwater and adding it to our drinking water supply?' Mr Colin Pitman's reply was:

The option of drinking water from stormwater is an option, but to notch up the production of drinking water from stormwater will add a significant cost to the economics of production of that water. That work requires significant matter of search work.

What I think he is saying there is that it requires significant research before we would be able to do it. He continued:

We however do know that, on a small scale, drinking water can be reduced from stormwater. It is not the target that Salisbury council is targeting because we believe the community's consumption for non-drinking purposes is the target where we should be directing our intention, and that's what we're doing.

And that is what the state government is doing. That is what the scientists are telling us. The science is telling us—

Members interjecting:

The SPEAKER: Order!

The Hon. K.A. MAYWALD: The scientists are telling us that, yes, on a very small scale, they can produce drinking water to directly—

Mr Williams interjecting:

The SPEAKER: Order! The member for MacKillop will come to order.

The Hon. K.A. MAYWALD: —put water into our drinking supply. However, on a larger scale, the costs would be prohibitive, and not only would the costs be prohibitive, but they could not guarantee the quality at this point in time. We have said in our Water for Good plan that it is not our intention, at this stage, to consider stormwater for potable purposes. What we do say, however, is that we will monitor the science and, should the science improve over time, and give us the confidence—

Members interjecting:

The Hon. K.A. MAYWALD: It is on about page 118 or 119. If you look at the document, it is written clearly there. We will consider the science and, if the science changes over the course of the plan and it does become economically and scientifically feasible to mitigate all risks associated with using stormwater directly into the potable supply, then of course it will be considered. But to supply water now: no, we are not going to put at risk the South Australian water supply into our homes for drinking water by putting stormwater directly into the supply—end of story.