Tuesday, May 31, 2011

Three Kings for a Blast from the Past


Last night, 30 May 2011, there was a meeting of the Three Kings Quarry Site Liaison Group (SLG) in the Hall of Three Kings Primary School. It was well attended because Winstone's - who run the Quarry - had given advance notice of its intention to recommence blasting operations in the floor of the quarry. Former Auckland City councillor Greg McKeown was in the chair as "mediator" by agreement with the various parties (Winstones, Three Kings United, South Epsom Planning Group, Puketapapa Local Board of Auckland Council). Christine Fletcher and Cathy Casey - local Auckland Councillors - were also in attendance. Cathy told me that the last SLG meeting held toward the end of last year - was the most acrimonious meeting she had ever attended! Hence a bit of agreed mediation.

My report from the meeting here is selective. The meeting started with short presentations from Three Kings United (Dianne Hill summarised their concerns as truck movements, aquifer pollution), South Epsom Planning (Dick Bellamy spoke of concern about future zoning of land when Three Kings is filled in, aquifer pollution, and worries about vibration, noise effects of blasting), and Puketapapa Local Board (Nigel Turnbull said it was "top of the list for us" Three Kings outcomes).

But clearly the main purpose of the meeting was to hear from Winstones. Present was Andrea Cave - Environmental Manager, Mike Harris - Engineering Geologist, Bernie Chote - General Manager, Tony Carpenter - Quarry Manager.

Mike Harris was up first. It appears there were a load of unanswered questions from the acrimonious meeting that Winstones had committed to answer. These related to site monitoring and were presented in a cluster of densely detailed power point slides. Interesting. We learned that the dewatering had drawn the water level down from 57 metres above sea level, to 34 metres above sea level. And that level had been held since 2002. Winstones operate 59 boreholes to monitor the groundwater. The key information related to absolute settlement and differential settlement of surrounding land. I think he told us Winstones have about 70 survey positions which they monitor to measure land subsidence. There are various triggers if differential settlement exceeds levels like 1 in 2000 between survey points. It appears some of those survey points have been "anomolous" because of effect of nearby tree roots pushing up local land levels etc. In summary it appears that overall land levels have subsided by about 75mm over a ten year period, but that there has very little differential settlement (this is what might cause cracks in buildings, foundations etc)...

Questions were asked about whether the water level would be lowered further (answer wasn't clearcut); whether the water that was discharged into Manukau was tested (No, but when the landfill is discharging then we may? / will? again - answer a little fudged); this led to another question about dischared water about duties to to test quality of water (answer this time was once landfill comes on will have to test the discharged water...)

Andrea Cave took the floor then (no photo. sorry). After speaking about the Env Court decision, it was her job to speak about the blasting proposal.

Turns out the Auckland District Plan (Isthmus) permits quarrying operations including blasting, subject to standards being met. These were particularly esoteric. For example:

  • 95% of blasts undertaken shall produce peak particle velocities not exceeding 5mm/second...

  • ... noise created by the use of explosives shall not exceed a peak overall sound pressure of 128dB...
  • In answer to a question from the floor it was established that the last time there had been a blast in Three Kings Quarry was 15 or 16 years ago. It struck me that this blasting provision in the district plan was a bit of a throw back - a blast from the past - that had somehow survived various reviews and plan changes and was still there, lurking, waiting to be dusted off....

    Andrea cave then explained the proposed Blasting Sirens Procedure, which is apparently derived from Winstone's Quarry Management Plan. This is set out here:
    Once blast area has been isolated, the shot firer will:
    5 minutes before the blast sound 5 short bursts of the siren
    30 seconds before the blast sound 1 long burst of the siren
    (The siren will be audible to all parties within the confines of Lot 1 DP 37020 being Three Kings Quarry)

    This led to considerable interest from the floor, and Bernie Chote stepped up to field them. Apparently the original procedure called for a 5 minute long siren, audible within The Three Kings Shopping Centre and very widely heard. "Very loud indeed" he said. Hence the lesser warning being proposed. Someone wanted to know about shift workers sleep. Chote said that was one of the reasons they wanted to tone it down a bit.

    He explained Winstones wanted to invite the SLG to attend a blast in July. Andrea had told us that a company called Red Bull is the specialist blasting company they propose. Apparently they did some work in Khyber Pass and Newton to enable pipes to be laid through basalt. They'd done the blasting without any trouble. Mr Chote took more questions:

    Q: How big will each blast be? A: 50 kilos of explosive each time in 20 drilled holes.
    Q: How long does a blast last? A: 3 to 4 seconds and then it's all over.
    Q: How many will there be? A: We plan one blast each week for the next 18 months.
    Q: Why are you doing it? A: We want to level the floor of the quarry.

    Mr Chote did not go on to explain why the floor needed to be levelled. But I can guess. It will make it easier to engineer a structurally robust fill, not subject to differential settlement - because it will be even - and so more valuable for building because it will support medium density and more. There was no information presented about the future use. However it makes sense to maximise that value for the shareholder (Fletchers). Steps are being taken to plan for this longer term future....

    Mr Chote ignored the question behind the pained complaint from the floor from one man, "I was promised by Winstones a long time ago that there would be no more blasting....". Silence fell after that. But not for long.

    Veronica has been involved in this issue for a long time. Dust on her house. Noise and so on. She wearily re-iterated the plan: "blasting twice a week for a year. Why more, after all that you have taken? haven't you taken enough. You've taken two Kings. There's only one left. Stop. Please....

    Dick Bellamy asked a lot of question in the course of the evening. At this point he wanted to know from Mr Chote, "what about fly rock?" After a little bit of discussion it turned out he meant that 50 kilos of explosive was very powerful and could throw loosened rock a long way. Apparently there had been houses with big rocks in their backyards after blasting in the past. Mr Chote assured him, "there will be no fly rock..."

    And here's me sitting in the back row taking notes. The residents were quiet it seemed to me. Well behaved. A bit mute really. It is a bit stunning to be told that your neighbour is allowed to start blasting after 15 years silence. And they don't even need a resource consent to do it. All because of an old bit of planning that should have been updated and tidied - I think - years ago. It's not even as if the material is like gold or something valuable - that is being mined - its like tidying up the site before subdivision. Even the Ports of Auckland Ltd backed off from explosives in the Rangitoto Channel when getting ready for bigger ships. And as for comparison with Red Bull's tiny charges in Khyber Pass - 50 kilos is a bloody big bomb. Disruptive and dangerous. If Winstones were serious about minimising the impact of this - they'd follow the Khyber Pass example and use lots of little charges. Chip away at it. Rather than seriously rock everyone's boat.

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    Tuesday, May 31, 2011

    Three Kings for a Blast from the Past


    Last night, 30 May 2011, there was a meeting of the Three Kings Quarry Site Liaison Group (SLG) in the Hall of Three Kings Primary School. It was well attended because Winstone's - who run the Quarry - had given advance notice of its intention to recommence blasting operations in the floor of the quarry. Former Auckland City councillor Greg McKeown was in the chair as "mediator" by agreement with the various parties (Winstones, Three Kings United, South Epsom Planning Group, Puketapapa Local Board of Auckland Council). Christine Fletcher and Cathy Casey - local Auckland Councillors - were also in attendance. Cathy told me that the last SLG meeting held toward the end of last year - was the most acrimonious meeting she had ever attended! Hence a bit of agreed mediation.

    My report from the meeting here is selective. The meeting started with short presentations from Three Kings United (Dianne Hill summarised their concerns as truck movements, aquifer pollution), South Epsom Planning (Dick Bellamy spoke of concern about future zoning of land when Three Kings is filled in, aquifer pollution, and worries about vibration, noise effects of blasting), and Puketapapa Local Board (Nigel Turnbull said it was "top of the list for us" Three Kings outcomes).

    But clearly the main purpose of the meeting was to hear from Winstones. Present was Andrea Cave - Environmental Manager, Mike Harris - Engineering Geologist, Bernie Chote - General Manager, Tony Carpenter - Quarry Manager.

    Mike Harris was up first. It appears there were a load of unanswered questions from the acrimonious meeting that Winstones had committed to answer. These related to site monitoring and were presented in a cluster of densely detailed power point slides. Interesting. We learned that the dewatering had drawn the water level down from 57 metres above sea level, to 34 metres above sea level. And that level had been held since 2002. Winstones operate 59 boreholes to monitor the groundwater. The key information related to absolute settlement and differential settlement of surrounding land. I think he told us Winstones have about 70 survey positions which they monitor to measure land subsidence. There are various triggers if differential settlement exceeds levels like 1 in 2000 between survey points. It appears some of those survey points have been "anomolous" because of effect of nearby tree roots pushing up local land levels etc. In summary it appears that overall land levels have subsided by about 75mm over a ten year period, but that there has very little differential settlement (this is what might cause cracks in buildings, foundations etc)...

    Questions were asked about whether the water level would be lowered further (answer wasn't clearcut); whether the water that was discharged into Manukau was tested (No, but when the landfill is discharging then we may? / will? again - answer a little fudged); this led to another question about dischared water about duties to to test quality of water (answer this time was once landfill comes on will have to test the discharged water...)

    Andrea Cave took the floor then (no photo. sorry). After speaking about the Env Court decision, it was her job to speak about the blasting proposal.

    Turns out the Auckland District Plan (Isthmus) permits quarrying operations including blasting, subject to standards being met. These were particularly esoteric. For example:

  • 95% of blasts undertaken shall produce peak particle velocities not exceeding 5mm/second...

  • ... noise created by the use of explosives shall not exceed a peak overall sound pressure of 128dB...
  • In answer to a question from the floor it was established that the last time there had been a blast in Three Kings Quarry was 15 or 16 years ago. It struck me that this blasting provision in the district plan was a bit of a throw back - a blast from the past - that had somehow survived various reviews and plan changes and was still there, lurking, waiting to be dusted off....

    Andrea cave then explained the proposed Blasting Sirens Procedure, which is apparently derived from Winstone's Quarry Management Plan. This is set out here:
    Once blast area has been isolated, the shot firer will:
    5 minutes before the blast sound 5 short bursts of the siren
    30 seconds before the blast sound 1 long burst of the siren
    (The siren will be audible to all parties within the confines of Lot 1 DP 37020 being Three Kings Quarry)

    This led to considerable interest from the floor, and Bernie Chote stepped up to field them. Apparently the original procedure called for a 5 minute long siren, audible within The Three Kings Shopping Centre and very widely heard. "Very loud indeed" he said. Hence the lesser warning being proposed. Someone wanted to know about shift workers sleep. Chote said that was one of the reasons they wanted to tone it down a bit.

    He explained Winstones wanted to invite the SLG to attend a blast in July. Andrea had told us that a company called Red Bull is the specialist blasting company they propose. Apparently they did some work in Khyber Pass and Newton to enable pipes to be laid through basalt. They'd done the blasting without any trouble. Mr Chote took more questions:

    Q: How big will each blast be? A: 50 kilos of explosive each time in 20 drilled holes.
    Q: How long does a blast last? A: 3 to 4 seconds and then it's all over.
    Q: How many will there be? A: We plan one blast each week for the next 18 months.
    Q: Why are you doing it? A: We want to level the floor of the quarry.

    Mr Chote did not go on to explain why the floor needed to be levelled. But I can guess. It will make it easier to engineer a structurally robust fill, not subject to differential settlement - because it will be even - and so more valuable for building because it will support medium density and more. There was no information presented about the future use. However it makes sense to maximise that value for the shareholder (Fletchers). Steps are being taken to plan for this longer term future....

    Mr Chote ignored the question behind the pained complaint from the floor from one man, "I was promised by Winstones a long time ago that there would be no more blasting....". Silence fell after that. But not for long.

    Veronica has been involved in this issue for a long time. Dust on her house. Noise and so on. She wearily re-iterated the plan: "blasting twice a week for a year. Why more, after all that you have taken? haven't you taken enough. You've taken two Kings. There's only one left. Stop. Please....

    Dick Bellamy asked a lot of question in the course of the evening. At this point he wanted to know from Mr Chote, "what about fly rock?" After a little bit of discussion it turned out he meant that 50 kilos of explosive was very powerful and could throw loosened rock a long way. Apparently there had been houses with big rocks in their backyards after blasting in the past. Mr Chote assured him, "there will be no fly rock..."

    And here's me sitting in the back row taking notes. The residents were quiet it seemed to me. Well behaved. A bit mute really. It is a bit stunning to be told that your neighbour is allowed to start blasting after 15 years silence. And they don't even need a resource consent to do it. All because of an old bit of planning that should have been updated and tidied - I think - years ago. It's not even as if the material is like gold or something valuable - that is being mined - its like tidying up the site before subdivision. Even the Ports of Auckland Ltd backed off from explosives in the Rangitoto Channel when getting ready for bigger ships. And as for comparison with Red Bull's tiny charges in Khyber Pass - 50 kilos is a bloody big bomb. Disruptive and dangerous. If Winstones were serious about minimising the impact of this - they'd follow the Khyber Pass example and use lots of little charges. Chip away at it. Rather than seriously rock everyone's boat.

    No comments: