How we manage our environment
Winstone Aggregates is committed to managing and minising the impact of our activities on the environment. We do this through an Environmental Management System (EMS). The EMS is our tool to provide accountability for our environmental performance on sites. It is a robust and flexible management framework that encourages openness and environmental improvement at all operational sites.
The Environment Policy gives direction to the company's EMS. It includes commitments by senior management for continual improvement, to strengthen core business operations and improve environmental performance.
We have an online resource consent management system to coordinate consents and conditions. This system is clear in the allocation of responsibilities, the setting of objectives, in compliance analysis and mandatory reporting. The system is used to undertake regular assessments and audits to confirm that regulations are met.
We value personal responsibility and individual employees are trained to consider how their work impacts their community. We have regular inspections and environmental monitoring to verify the impact and success of mitigation measures. It is this undertaking that keeps us accurately informed and allows us to display our commitment of continual improvement in the environmental management of our operations.
At Hunua Quarry south of Auckland, Winstone Aggregates has developed, implemented and monitored a programme for the rare Auckland Green gecko. This is part of a wide-ranging environmental mitigation and enhancement programme. A taonga species for local Iwi, Auckland’s tree-dwelling green gecko, or Kakariki is classified as an 'at risk' species by the Department of Conservation. Periodically Winstones needs to clear vegetation on its sites to access more high-quality rock due to demand, it is important to ensure the environmental impact is minimised. Prior to any vegetation being cleared, there is an extensive process to make sure the business does not impact any wildlife.
This is done by undertaking a biodiversity survey of the area, cutting lines into the vegetation area, then leaving the understory vegetation on the ground for a week. This time on the ground allows the geckos who were in the understory vegetation to relocate into the remaining, higher vegetation so they are much easier to spot under spotlighting conditions. The gecko are then captured during night time surveys.
The salvaged geckos are taken to a new home in the Hauraki gulf where experts and the Department of Conservation (DOC), are better able to monitor their health.
A wider range of restoration initiatives such as planting indigenous forest are being undertaken by Hunua Quarry. This is to compensate for habitat which will be lost through works associated with the development of the new Symonds Hill pit. These include control of predatory pests over an area of 100ha of surrounding regenerating forest adjoining the proposed pit. This mahi has focussed on rats, possums, stoats and feral cats.
This reaffirms our commitment to reducing the effects of our operations on the environment and if possible, returning it to a better state before our activities began.
The ongoing development of Belmont quarry created the environmental opportunity to preserve gecko species numbers, to re-establish a community of Ngahere gecko’s on Mana Island and to support local community groups in their conservation efforts.
Belmont Quarry’s ‘Firth Block’ is known to be a potential habitat of Ngahere gecko and to a lesser extent Wellington Green “barking” gecko (no barking geckos were found within Belmont Quarry). The Ngahere geckos are recognised as an at-risk species and therefore Winstone Aggregates were legally obliged under the Wildlife Act to translocate Ngahere geckos before facilitating ongoing access to the underlying aggregate resource. This development required the removal and disposal of vegetation and overburden (the material overlying the quarry rock), from the area known onsite as the ‘Firth Block.’
While this programme aimed to mitigate the further loss of Ngahere gecko populations, Winstone Aggregates chose to go beyond the minimum requirements of the Wildlife Act and in particular work with and involve stakeholders wherever possible, in this case Taranaki Whānui ki te Upoko o te Ika and Ngāti Toa Rangatira, Friends of Mana Island, DoC and Wellington Zoo.
Winstone Aggregates engaged ecologists to trap and capture geckos found on site using closed cell foam covers and spotlighting techniques. The geckos were then transferred to Wellington Zoo for checks and quarantine. Following clearance from Wellington Zoo the geckos were transferred to Mana Island where the aforementioned key stakeholders; DoC, Ngāti Toa, Friends of Mana Island and Taranaki Whānui ki te Upoko o te Ika and Ngāti Toa Rangatira were invited to take part in post-release monitoring.
Gecko relocation programme covers three stages of a thirty five year project.