Quarry gets clamp down under review of consent conditions

An Auckland Regional Council review of a Winstone Aggregates Ltd consent to take groundwater from the Three Kings Quarry has resulted in tougher restrictions on dewatering at the quarry.

The review was ordered by the ARC, after inaccurate information on the effects of dewatering was provided in the original consent application in 1997.

The review decision, made by three independent commissioners, stated that Winstone could continue dewatering the Mt Eden Rd quarry, in order to extract scoria, but only if stricter controls and monitoring were implemented.

The commissioners based their decision on rigorous scientific analysis of potential environmental impacts from groundwater removal.

Winstone will now be required to monitor ground settlement levels from dewatering every three months, as opposed to every six months under the original consent. The designated monitoring area is also substantially larger than it was previously.

The dewatering is to cease once ground settlement limits, which are four times more stringent than in the original consent, have been reached.

A bond of $5m, which would be used to mitigate any unforeseen environmental impacts that may occur, is also required.

ARC water resource scientist Alastair Smaill said studies of the quarry site showed that environmental impacts from taking additional groundwater would be negligible if dewatering restrictions were imposed.

“In making this decision community interests were paramount,” Mr Smaill said. “As a result the commissioners have imposed strict conditions on the quarry in order to protect the community from potential risks of dewatering.”

The commissioners assigned to the review were two expert engineers, Dr Laurie Wesley and Graham Wheeler, and long-time commissioner Ken Graham. Appeals relating to the decision must be lodged with the Environment Court within 15 working days of the decision.

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