How old is the water in the Kangaloon Aquifer?

The absolutely critical question in the whole debate over the Government’s proposal to drain the Kangaloon Aquifer is "How old is the water in the Kangaloon Aquifer"?

Mr Iemma said the aquifers could supply two years of backup water until they were emptied. They would take five years to replenish (he said).

My personal opinion of this proposal, and especially this replenishment time “guess” is on record. As I said on 13 February:

…. Water from the aquifers has been tested, and shows that at about 200 metres depth, the water is roughly 1000 years old. (SMH Feb, 9, 2006 - “The myth of Sydney being drought-proofed”).

Now the SCA has produced a pamphlet about the Kangaloon Aquifer, which they were handing out at the Robertson Show last weekend. Good. Some information, at last. In part, it says:

Specialist investigations are now under way to fully assess the size of the groundwater resource. Studies include detailed water chemistry, environmental isotope analysis (dating), pumping test analysis, borefield modelling, and ecosystem impact studies.

These studies will confirm the likely environmental impacts (if any) and refine the current predicted sustainable pumping volumes.

Good news. Such studies, especially the “ageing” of the water are critical knowledge, which is absolutely necessary to planning of the proposal to drain the Kangaloon Aquifer. So, how can SCA justify the following 2 statements, in the same pamphlet?

How old is the groundwater?

Groundwater across the Sydney basin is variable in age. The Upper Nepean groundwater has been dated from modern (recent rainfall) to a few thousand years old. These ages are typical of sandstone aquifers in recharge areas where recharge is constant and the resource renewable.

How long does it take for the groundwater to recover?

Recovery times, like the age of groundwater, are highly variable. For the Upper Nepean borefield area, it is expected that water levels would recover in periods of approximately five to seven years if average to above-average rainfall patterns prevailed.

(From SCA Pamphlet about the Kangaloon Aquifer.)

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We know that they do not know how old the water in the Kangaloon Aquifer really is. They admit that, by saying they are going to commission someone (presumably ANSTO) to age it, by isotope analysis.

So, how can they justify making this ridiculous statement?

”…it is expected that water levels would recover in periods of approximately five to seven years if average to above-average rainfall patterns prevailed”.

They simply do not do not have the science to back up the claims which they and the Premier have been making.