The top of the aquiferThe top of the aquifer
This is a general view looking into the quarry. The ponds are the top surface of the aquifer. The water extends downwards through the ground for several hundred metres into the crater of the volcano. The water extraction pump is located about 80 metres below the quarry floor level.
When the de-watering commenced the pond water was drawn down towards the pump taking with it the contaminants from the surface. At the present time the water is being pumped through the existing stormwater pipes and into the Manukau Harbour at a rate of 5000 cubic metres per day. Metro Water Ltd want to pump it into our taps because it is cheaper for them than continuing to provide us with the higher quality water from the Waitakere Ranges. The quarry owner, Winstone Aggregates Ltd, would also gain a considerable financial advantage.
Councillor Raffills told the council recently that Winstone's could have earned about $1,000,000 during the 14 months that the drinking water supply scheme has been delayed. Some of the water comes from the ground deep under our houses, and as a consequence of it being removed from the ground, the ground is subsiding.
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