White Rock Quarry run-off muddies Third Creek and angers residents at Horsnell Gully and downstream

Water quality has become the latest source of conflict in the battle against the expansion of an Adelaide quarry. Read the Q&A.

After heavy rain, Third Creek receives dirty run-off from Hanson White Rock Quarry at Horsnell Gully, 10km east of Adelaide, near Norton Summit.

Now the Residents Against White Rock Quarry have pinpointed the location where this opaque coffee-coloured water mixes with clear water from the Hills. They want the quarry to clean up its act and “back off”.

But Hanson is pressing ahead with plans to expand and will letterbox residents with an update this week, which says: “Hanson has made every effort to ensure continuous improvement in water quality management”.

The Environment Protection Authority said photographs showed water quality after heavy rain was not acceptable, representing noncompliance with their licence to operate. (See detailed Q&A below).

The Energy and Mining Department anticipated the issue in a letter to the company dated July 20.

The company is applying to the EPA for a second sediment basin to capture more water and allow the sediment to settle before use or release downstream.

“Hanson has recently invested $2.5m for construction of a basin to assist the treatment and settling of sediment,” the company’s letter to residents states.

“This water will be recycled onsite for dust suppression; used in the manufacture of concrete; or released into the Third Creek catchment. We have already observed a 44 per cent reduction in total annual discharged sediment.”

A spokesman added, ”We are now working through design and submission to EPA for a secondary sediment basin, which we anticipate will provide further improvements to reduce any downstream sediment flows.”

Shayne Varacalli of Magill said he was “most concerned about the brown water that comes down the creek from the quarry”.

“It leaves sediment in the creek, depending on what flows come after it and there seems to be no action on behalf of the EPA to allay anyone’s fears, at this point,” he said.

Residents Shayne and Elaine Varacalli at the site where Third Creek receives murky runoff from the Hanson White Rock Quarry at Horsnell Gully. The photo was taken close to the corner of Old Norton Summit Rd and Horsnell Gully Rd. Picture: Supplied.

Residents Against White Rock Quarry (970 members and growing) campaign leader, Demetrios (Jim) Bastiras of Skye, said the issue of water quality in Third Creek was important for residents across Adelaide because the waterway runs through Skye, Teringie, Magill, Tranmere, Firle, Payneham, Glynde, Marden, Felixstow and into the Torrens River.

“We’ve noticed much less water in the creek over time,” he said.

“The water runs dirty because of the mine, which shouldn’t be surprising: the mine is an 40 hectare open pit of eroding rubble. To think that they want to expand it by 400 per cent to 200 hectares!

“The community finds this unacceptable. Add to this they get use the water for free. “Heidelberg Cement Group’s solution is to build yet another tailings dam, which will dry the creek up even more in spring and summer. So we’re face with a choice: dirty water, or no water. This is not on. They will never achieve a social license for this expansion proposal.”

READ THE FULL RESPONSE FROM THE STATE GOVERNMENT BELOW:

The Department for Energy and Mining (DEM) is the lead regulator of the White Rock Quarry, and the Environment Protection Authority (EPA) and DEM have already proactively undertaken compliance actions in regard to this sediment runoff.

Q: What are the current water sources and storages for Hanson’s White Rock Quarry water, including volumes?

A: Mains water, stormwater and recycled wastewater. Storages include a type of dam, stormwater tanks and sediment basins. The volume of water is dependent on the amount of rainfall.

Q: Is the company allowed to capture and use all of the water that falls on their property?

A: It is allowed to capture clean stormwater and use it for operational purposes or release it once suitably clean into the Third Creek catchment.

Q: What are the rules around quarry runoff and discharge into Third Creek? Is Hanson breaking any rules or doing anything wrong?

A: Yes. Hanson is required to achieve the compliance objectives and conditions of the Mining Operations Plan and EPA Licence for stormwater. This is not being achieved at present and DEM and the EPA took compliance action on 20 July 2021 with the intent of reducing the level of sediment leaving the site. We acknowledge that Hanson is working toward bringing the site within compliance by spending a significant amount of money on the existing sediment basin.

Third Creek. Brown creek water from the quarry, joining the clear water from Third Creek. Picture: Supplied.

Q: Looking at the photos and videos, is this situation acceptable?

A: No this is not acceptable and regulatory action has been undertaken accordingly.

Q: What should residents do when they see this? Report it to who / where / how?

A: Residents can report this to the DEM customer service number on [phone] or the EPA 24 hour Emergency Response Team on [phone]. Dates, times, exact location and photos of the pollution are helpful.

Q: I expect there are similar situations elsewhere, do you know where? Is there general advice we can give readers about supporting water quality in their local area?

A: Higher than average rainfall in July has caused increased turbidity with surface erosion from a number of sources. Everyone in the community has a part to play in reducing pollution in stormwater. Click here for more.

Q: What about the Hanson proposal for a secondary sediment basin, is that a good idea and how would that help? Wouldn’t that also reduce flows in Third Creek? Is that acceptable?

A: Hanson is required to take further measures to manage the stormwater on site including re-construction of the second sediment basin to capture more sediment and retain it on site. Capturing and treating the turbid stormwater to the required water quality prior to release will reduce the sediment discharge into the Creek. It is expected that the design of the secondary basin will maximise environmental water flows whilst effectively cleaning the water leaving the site.