Quarry spill dyes creek
A spill from a quarry stormwater pond caused alarm in Drury after a milky-grey substance turned up in a local stream.
Locals in the rural farming community called the Auckland Council on Sunday morning after they noticed a culvert near Stevenson's Drury quarry had turned a milky-grey colour and waste was escaping into the Hingaia Stream more than a kilometre away.
The Hingaia is a feeder stream for Drury Creek which eventually enters the Manukau Harbour via the Pahurehure Inlet.
Stevenson Group spokeswoman Alison Hunter says the spill was from an old stormwater pond which was being filled in over the weekend.
Some time during Saturday night a pile of fill on the edge of the pond fell in, causing "a slurry of soft and unconsolidated material" to overflow into a drain, she says.
The substance was "not a pollutant" but rather silt from fine dust particles from quarrying activities.
Ms Hunter understands council staff tested the water at the time and the pH was normal.
The company regrets the incident and is reviewing its procedures for carrying out such work in future, she says.
Stevenson Group's website says it treats all water used at its quarries to ensures the "quality of water re-entering local streams is of a high standard".
Auckland Council's pollution response team reported the spill could be seen approximately 70 metres down the culvert leading from the quarry, council spokeswoman Sharne Parsons says.
The council ordered Stevensons to divert the culvert and close it off with earth at either end, containing the discharge to avoid further contamination of water downstream. The council will continue to monitor the effects on the environment before deciding upon any further action, she says.