Neighbourhood meeting and community update

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.