Calga Sand Quarry MOD.3 Crushing System

Central Coast Greens Presentation

Presenter: Douglas Williamson, B.Sc., Dip.Ed., M.Env.

  • I wish to acknowledge that we meet today on Darkinjung, Gu-ring-gai and Awabakal country and offer my respect and thanks to their elders past, present and future and to any other indigenous people present. This land was never ceded and remains now and forever aboriginal land.
  • Central Coast Greens reject the application to install a crushing plant at the Calga Sand quarry on the grounds outlined below.

 Air Quality Conditions of approval

 Prior to this amendment being possibly approved, it is imperative that the proponent conduct actual, independent and NATA accredited on –site testing of air quality, esp PM2.5, as opposed to irrelevant modelling conducted for a western Sydney airshed. This is due to the modelling used being based on measurements taken at the end of a sunken riverine basin of airshed of the largest city in the country with a population of 4.4 million people, living in 1.64 million dwellings at 2011 census (ABS 2017), as opposed to a small ridgetop, rural-urban fringe settlement of approximately 330 people, living in 112 dwellings (op.cit).

  • 5 testing. This particle size cannot technically be extrapolated from PM10 levels, as the regression coefficients between these 2 different particle sizes differ typically by up to 50%. (Williams, 2000) Pre-commencement testing, ongoing monitoring, remedial action trigger levels and enforceable toxic load limits must be implemented for on-site PM2.5 generation by this type and size of plant as outlined by Commonwealth goals which have come into place since 2004 (NEPC 2017), after the initial EIS for the Calga Sand quarry Southern extension was completed.

Vibration Impacts

  • The vibration modelling is based on buried pipes; circular in profile, bedded in sand to reduce vibration impacts. Expert evidence was given during the previous LEC case that vibration around an islanded site on the F3 has led to the splitting of Whale Rock at Berowra on the same rock unit of Hawkesbury sandstone as occurs at Calga Sand quarry. (Owen 2017, Packham 1969) According to the Cumberland Ecology report (2009), the rock type on-site is Hawkesbury sandstone, a hard (Packham 1969, Pienmunne & Whitehouse 2001) and therefore brittle material. Due to these 2 properties of the rock on-site the use of a crushing plant will transmit vibration readily and pose a significant threat to the identified and yet to be identified aboriginal art sites and the structural integrity of nearby landforms of further aboriginal cultural significance.

Quarry Operations

  • Is resource to feed this crusher coming from currently exhausted quarry cells? If yes, this will mean excavating deeper and thereby damaging further the head of the aquifer feeding into the Mangrove Mountain dam, which is the potable water supply for 317 000 + people residing on the Central Coast. Will this comply with the Groundwater Management Plan; Surface and Groundwater Contingency strategy which were to have been prepared as Condition 25, Schedule 3 of AWWP/Rocla Agreed Conditions, pertaining to the effect of quarry operations on Groundwater Dependent Ecosystems, a number of which, on this site, are endangered under NSW Threatened Species Conservation Act (1995)? This must be monitored by a NATA accredited, independent consultant on behalf of Department of Primary Industries, Water at the proponent’s expense; with enforceable penalties in place should any further excavation of quarry cells 3 or 4 occur. Such third party monitoring is essential following evidence of previous incompetence and/or conflict of interest in monitoring in the case of Mangrove Mountain landfill site by previous Gosford Council and EPA, which has led to a complete loss of the community’s confidence in both of these governance bodies.
  • If no, will this quarry be used as a centralised crushing depot for a number of currently uneconomic, smaller deposits in the local area? What are the ensuing traffic, dust, noise and vibration implications of such an escalation in traffic volumes of heavily laden trucks in this small, semi-rural township where we meet today? Will V-doubles be utilised in such a transport operation? Such plans are currently denied, yet when this DA was lodged 6/16, only after the requisite community consultation meeting did the proponent raise this amendment including a crushing machine. This was justified by the proponent on the grounds that they hadn’t wanted a crusher at the time of meeting. If the proponent is either incapable of planning or cannot be trusted on this, can they be trusted to not use this amendment as a stalking horse for turning Calga Sand quarry into a central processing plant for such smaller mines?

Approval Conditions

 What guarantees (or environmental bonds) are there against extensions / variations to this amendment, should it be approved? What are the consequences for exceeding these approvals, are they adequate preventative measure in view of auditor-general; how will they be monitored and who will check and enforce potential limitations? This is particularly relevant in light of the recently released Auditor General’s report into mining rehabilitation security deposits, which stated that ‘there is…no financial assurance held over the risk of significant unexpected environmental degradation in the long-term after a mine is deemed to be rehabilitated’ (Audit Office NSW 2017). Furthermore, McNally (2017) in a response as secretary of the Department of Planning and Environment stated that ‘current operations are responsible for rehabilitation and all mines (to) lodge a security deposit for the full cost of rehabilitation at the start of operations.’ What mechanisms exist to prevent post-dating of approvals to exceed conditions of operation? Are such mechanisms in place and effective?

In conclusion, for the reasons outlined above and a number of others omitted for brevity, the Central Coast Greens categorically reject this application for an amendment to the proponent’s DA to install a crushing machine in the Calga Sand quarry.


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PIENMUNNE, J.T., WHITEHOUSE, J. 2001. Supply and Demand for Construction Sand in

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