White Rock Quarry (Hanson)

The EPA and DEM would like to sincerely thank residents in Magill who invited us to their neighbourhood gathering, to talk about Third Creek, water quality monitoring, and the White Rock Quarry. Questions raised by the community at this meeting and via this website include:

Q: Does the Quarry have to meet modern environmental standards?

A: Yes. Whilst DEM is the lead regulator for the White Rock Quarry, Hanson is required to meet environmental standards within the Environment Protection Act 1993, Environment Protection (Water Quality) Policy 2015 and Environment Protection (Air Quality) Policy 2016. This includes the most recent EPA interim standards for protection of communities from Respirable Crystalline Silica (RCS). 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, which is particulate matter or dust particles less than 10 micrograms (µg) in diameter, for 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.

Q: Does the Quarry require a licence to use the water in its dam?

A: No. The facility is not located in the Western Mount Lofty Ranges Prescribed Water Resources Area. This means Hanson can use the water from its dam without requiring a water allocation or licence from the Department for Environment and Water.

Q: Why does the EPA rely on Hanson to monitor water quality and not do so itself?

A: The EPA requires all EPA licence holders to demonstrate their operations can meet EPA legislation and environment protection policies. Qualified EPA scientific staff assess both monitoring programs proposed by operators and whether the resultant information provided is adequate. It is important this is commissioned by the proponent and not the EPA using public funds. The EPA does however, on occasion undertake independent water quality monitoring. DEM also uses a surveillance camera to verify and monitor water quality in real-time for Third Creek and other creeks downstream of quarries to cross-reference images from the camera with the data provided by licencees.

Q: Did DEM issue Hanson with a Compliance Order because of chemicals being added to the water as claimed in the media?

The use of chemicals was not among the reasons the compliance order was issued. Whilst the use of flocculation is common and approved for sediment control in the extractive industries sector, the Quarry was not, and still is not, authorised to use chemicals to treat surface water at the site. There is no evidence to suggest the company has used chemicals for this purpose at the site in the past. Evidence suggests the use of flocculation would help improve the quality of the runoff leaving the site, however appropriate approvals would need to be granted prior to use.

Q: Could sediment in Third Creek since August 2022 be affecting the frogs?

The EPA wouldn’t expect any Mount Lofty Ranges frog species to be impacted by sediment from a creek, as the adults are found mostly on the wet banks and among emergent plants on the wet edge, and can avoid pulses of poor water quality. However we are keen to ask further questions and discuss this matter and observations made by residents in more detail. We are looking at arranging a follow-up visit with residents from the Friends of Third Creek on water quality issues and invite anyone interested to contact us on engage.epa@sa.gov.au if you would like to be involved.

Q: Do your air quality stations monitor 24/7 or take samples at random times?

Hanson currently undertakes continuous 24/7 air quality monitoring of PM10 at an offsite location in the community (please see the online interactive map). It also undertakes dust deposition monitoring, which captures all the dust deposited from the air at set locations, over a period of one month. The EPA has a network of air quality monitors across metropolitan Adelaide that is used to distinguish high regional dust events that affect the whole of Adelaide, from local sources such as quarries.

Q: What is being done about contractor trucks leaving the weighbridge with loads uncovered?

Hanson has procedures in place to require trucks to be tarped prior to leaving the site, although it is still possible some may be missed. The online interactive map on this website can be used for residents to record the date, time, and either truck licence plate or as much description of the truck as possible. Alternatively please email engage.epa@sa.gov.au to enable targeted follow ups to be most effective. Unsafe activity including driving with an unsecured load or speeding on SA roads is regulated by the SA Police, and can be reported either by phone or SAPOL’s Traffic Watch app for investigation by Police.

Q: How long has the concrete batching plant been operating?

A: Most likely sometime prior to 1968. Both DEM and the EPA have regulatory oversight over this activity and associated impacts through the Mine Operations Plan, and as a prescribed activity listed on the EPA licence.

The Department for Energy and Mining (DEM) undertook a social research survey regarding community engagement and White Rock Quarry. DEM sought residents' views on how Hanson and DEM communicated with them during 2020-2022 about the proposed quarry expansion, and related revisions to the quarry’s mine operations plan. This social research was aimed at understanding how quarries and communities interact, particularly when the quarries are close to residential suburbs.

Tom Sweeney from 150 Research (https://www.150research.com/) is an independent consultant who was appointed by DEM to undertake this work.

If you have any questions, please email DEM.MiningRegRehab@sa.gov.au.

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.

On 20 May 2022, DEM issued a compliance order under the Mining Act 1971 to address surface water management issues at the site and a number of the EPA’s regulatory requirements are incorporated into this Compliance Order.

The EPA will continue to support DEM and ensure EPA’s regulatory requirements are met through DEM’s consolidated compliance strategy (or independently where applicable).

On 8 September 2022, the EPA's Emergency Response Team received a report of a white discharge visible in Third Creek at Melory Crescent, Magill. Photographic evidence was provided by the resident, taken at approximately 4:25 PM.

An EPA staff member arrived at the site at approximately 4:55 PM and all traces of the white substance had dissipated both upstream and downstream (please see photo gallery). The was very high rainfall throughout the catchment at the time, the flows were very high in speed and volume, and as a result the substance would have been heavily diluted and pushed downstream very quickly. No other downstream witnesses reported a white plume to the EPA at the time. Sediment loads within the creek were observed at all locations, which were consistent with the water coming in from the surrounding catchment under high volume heavy rainfall.

Turbidity within Third Creek was impacted by sediment from a number of sources, which is common when there is high rainfall. On this occasion however, the EPA investigated Hanson’s site operation and real time monitoring data and determined the white discharge had not originated from White Rock Quarry. However, EPA acknowledges Hanson still has a contribution to the sediment discharge to the Creek (please refer to 'surface water management' section below).

Line marking being undertaken and having washed away along the route was also ruled out as a source after further investigation. Due to the short-term nature of the discharge, the EPA considers that an isolated event such as paint or another substance inadvertently or deliberately being discharged to the Creek was the cause of the pollution, however is not able to confirm the source on this occasion.

We would however, like to strongly encourage residents to please keep reporting events to enable us to investigate, as whilst this incident was not able to be attributed to an offender there are many occasions when it can be and we value the community's support of our regulatory efforts.

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 13 September 2021 Hanson commenced its Ambient Air Quality Campaign (PM10) after active engagement with the EPA, DEM and other stakeholders.

On 19 April 2022 the EPA issued an expiation to Hanson for failing to develop and submit a Dust Management Plan to the satisfaction of the EPA. This plan has now been submitted and approved by the EPA.

Since May 2022, the EPA has been provided with and analysed the data on a monthly basis. Until 31 August 2022 the EPA has noted two exceedances of particulate matter 10 micrometres or less (PM10). All results have been below health criteria and comparable to the EPA’s permanent air quality monitoring stations in Adelaide and Netley, with the exception of two days in late June 2022 where it is believed a controlled burn was conducted in the surrounding area and captured by Hanson’s equipment.

See 'Respirable Crystalline Silica' (RCS) section below for information on RCS-specific monitoring.

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.

After active engagement with the EPA, DEM and other stakeholders, on 7 July 2022 Hanson commenced its Ambient Air Quality Campaign for Respirable Crystalline Silica (RCS). The EPA’s criterion for RCS is that Hanson must operate below the 3 micrograms per cubic metre (μg/m3) on an annual average. At this stage we are pleased that Hanson is undertaking a regular RCS monitoring and providing data on a regular basis to the EPA. Early data indicates that this is currently being achieved however the EPA will conclude whether Hanson is compliant after a full 12 months of monitoring is complete and will work with DEM to ensure compliance.

The EPA is aware that Hanson 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.

For further information, please visit the DEM website relating to the MOP.