White Rock Quarry (Hanson)
Roles of the regulators
The Department for Energy and Mining (DEM) is the lead regulator of the White Rock Quarry.
Hanson Construction Materials Pty Ltd (Hanson) must achieve the compliance objectives and criteria of its mine operations plan (MOP), which is regulated by DEM under the Mining Act 1971.
Additionally, Hanson holds an EPA licence (No. 12714) and must comply with the conditions of this licence, the Environment Protection Act 1993 (EP Act) and relevant environment protection policies (EPP).
The EPA and DEM work as co-regulators to ensure that regulation of Hanson is efficient and without unnecessary duplication, and that the environmental requirements are effectively ensured.
The EPA provides scientific and technical advice to DEM to assist its regulation of the site operator, and, if necessary, can step in with additional regulatory approaches.
Management of dust is a vital aspect of quarrying activities and has been the subject of increased community concern at this site since 2021.
Since February 2021, Hanson has been required to establish a dust monitoring system. More recently the EPA further strengthened Hanson’s licence with a new condition requiring it to develop and implement a Dust Management Plan (DMP). This will facilitate the identification of potential dust sources, installation of a dust monitoring system, dust management strategies and complaint management. The plan also enables use of real-time monitoring data to demonstrate compliance with EPA health criteria and to identify, in the shorter term, nuisance dust. The monitoring will inform early actions to prevent off-site dust impact.
On 19 April 2022 the EPA issued an expiation to Hanson for failing to develop and submit a DMP to the satisfaction of the EPA. This plan has now been submitted and approved by the EPA.
Respirable crystalline silica (RCS)
Silica is silicon dioxide (SiO2), a naturally occurring mineral that forms a major component of most rocks and soils. There are non-crystalline and crystalline forms of silicon dioxide. Mechanical processes such as crushing, cutting, drilling, grinding, sawing or polishing products containing silica can generate respirable particles (PM10) small enough to penetrate deep into the lungs, which can cause irreversible lung damage. These compounds are referred to as respirable crystalline silica or RCS.
There has been significant work at a state and national level to understand the health implications for workers − including a review of safe levels − since they may be exposed to hazardous levels of RCS. More information can be found in Silicosis in Mining and Quarrying in South Australia information sheet.
The EPA, with input from SA Health, undertook an extensive literature review of the modern criteria for RCS in ambient air for mining and extractive industries. Based on this, the EPA is adopting an interim RCS criterion for the mining and extractive industries of 3 μg/m3 (annual average) for the PM10 size fraction of dust in ambient air. The PM10 size fraction selected is based on a precautionary approach, which will ensure communities are well protected from any adverse impact of RCS in ambient air.
Hanson is undertaking a 12-month crystalline silica monitoring campaign to determine background concentrations from its current operations. The results of the campaign can then be used to determine if the concentrations are within acceptable limits inside the quarry and the likely predicted ground level concentration at receptors.
Surface water management
Quarries have the potential to be a major contributor to sediment discharges to sensitive waters. In 2015 the EPA conducted an extensive water quality audit and investigations. Since then it has been engaging with Hanson and driving improvements at the White Rock Quarry.
In 2017 Hanson was required (through a licence condition) to develop and implement an environment improvement program (EIP) in line with the Environment Protection (Water Quality) Policy 2015. The purpose of the EIP was to identify and undertake a range of short-, medium-, and long-term actions to improve stormwater quality and reduce sediment discharge off site.
In addition, a water quality monitoring program that was stipulated in its EPA licence required Hanson to engage independent consultants to conduct continuous water quality monitoring at the site. This data is reported to the EPA on a quarterly and annual basis, and the results inform the effectiveness of existing and implemented management measures.
Significant improvements have been made through the actions implemented in the EIP, including diversion of conservation park clean flows, site drainage and sediment capture structures, and construction of a sediment basin (SB1) to treat stormwater.
Additional management actions required under the EIP include the construction of a new sediment basin (SB2A) and the refurbishment of the existing sediment basin (SB2B) to further assist in managing surface water during high rainfall events. In addition, Hanson is in the process of reviewing the site’s water quality monitoring plan, and developing a water quality trigger action and response plan (TARP).
However, discharges from the site have continued to exceed standards at times and further work is required.
A major milestone in the EIP involves implementation of an active treatment basin, where water undergoes an advanced settling process. This innovative technology is expected to make a significant improvement to Hanson’s existing sediment management strategies.
Hanson had committed to completion of active treatment technology by April 2022 but this was not achieved.
The EPA has been working with DEM to determine an appropriate regulatory response. On 20 May 2022, DEM issued a compliance order under the Mining Act 1971 to address surface water management issues at the site caused by failing to implement an active treatment basin in an appropriate time.
DEM is the lead regulator for the ongoing regulation of sediment discharges from the site, and the EPA will continue to provide technical support.
The EPA is aware Hanson has submitted a mine operation plan (MOP) detailing its long-term quarry development plans. DEM is responsible for assessing and approving the MOP in accordance with the Mining Act 1971. Where appropriate, the EPA will:
- Provide technical advice and ensure requirements under the EP Act are incorporated into DEM’s assessment.
- Ensure environmental obligations under the EP Act are incorporated into the MOP.
Further information relating to the MOP.
Communities can report any matters to DEM or the EPA 24-hour Emergency Response Team with dates, times, exact location and photos.
To contact Hanson directly, please call (08) 8431 4866 or visit its website.