With the fate of its proposal to extend its sand mining operations to land to the south and east of Dunmore House (reported extensively in previous editions) still to be decided, Boral invited The Bugle to tour its existing sand mining operations to get an understanding of its local remediation track record.
Sandmining began at the Swamp Road Quarry in 1999, with the operation being bought by Boral in 2005.
Throughout that time, progressive rehabilitation of the site has been undertaken, seen in the well established Dunmore Lakes (adjacent to the Estate) and the developing coastal wetlands within the still operational stages further north.
“The trees around Dunmore Lake are 10 years old,” says Boral’s Environmental Coordinator for Dunmore, Ben Williams.
“There are 6,300 tubestock planted in the area, and they’ve really taken off.”
The plants have been supplied by Jamberoo Native Nursery, from local seed stock.
Bird islands have been established as a safe home from predators like foxes, and the early site has won a number of awards for best practice.
“Once we finishing dredging in an area we backfill to provide an edge to the lake,” says Mr Williams.
“The buttress slopes provide different habitats for birds and fish.”
Together with Boral’s Planning & Development Manager, Adnan Voloder, he explained that the proposed sites across the highway, to the east and south of Dunmore House, share many similarities with the existing operations – such as the extraction method, the processing plant (to which the sand will be pumped through existing and new pipes) and the method of rehabilitation.
“The rehabilitation methodology will be the same, but we will be using a different range of species to establish a Bangalay forest community, rather than the Swamp Oak community on the west of the highway,” says Mr Williams.
Apart from these well established practices, the larger pond (which is to be left as a lake on the request of the property owner) will have a bund surrounding it during the operational phase to isolate its water in the case of a 100 year flood (the bund will be a seeded mound around the pond, to raise the edges of the site).
“The intention is to make sure that, in the event of a flood, there is no interaction between our waters and the flood waters,” says Mr Voloder.
This measure is not to protect the river but to contain the sand in a flood event.
“The water in our ponds will be of a higher quality anyway [without farm residue], but the bund will stop us losing the resource.”
He is adamant that the proposed pond will never take water from the river.
“The river is down hill from the area. It would have to flow up hill.”
Mr Voloder understands that people may have misunderstood the reference to a 27 metre depth for the larger of the ponds. It is one of the things he is clarifying with the Department.
“It is a theoretical limit found by our test drilling at one point, not throughout.”
As the hill that Dunmore House sits on is a large latite rock, the closer you get to it the shallower the sand resource. Closer to the river, the sand is deeper.
The dredging of the pond will be guided by the depth of the resource and the need to keep a slope around the edges for stability.
With regard to concerns about the smaller pit, opposite Minnamurra Waste Depot and its known leachate plume, Mr Voloder says they are disconnected hydrologically.
“The consultant reports are satisfied that the risk of the proposal is very low in terms of having an impact on the coastal environment,” says Mr Voloder.
“Our consultants, Earth & Environment Systems, have been working in this region for 15 years and have a very good knowledge of the aquifer, which covers a few square kilometres.”
He says no government agency has objected to the proposal to extend its existing permissions to the new sites across the Highway. Instead they have asked for clarifications and are preparing conditions in response.
Clarifications have recently been supplied to the Biodiversity & Conservation Division of the Department of Planning, Infrastructure & Environment, with regard to aboriginal cultural heritage, biodiversity, water flooding and mitigation measures.
In contrast to this reception, Boral’s proposals have been strongly opposed by Kiama and Shellharbour councils, Friends of Minnamurra River, the Progress Association and at community rallies.
Gareth Ward, the Member for Kiama, also recently spoke against the matter in Parliament.
Boral’s response to their submissions is due shortly.
Richard Maitland, of the Friends of Minnamurra River, and a group of others opposing the expansion, including Cliff Mason and Warren Holder, visited the Swamp Road Quarry in April but did not tour the existing operations or the proposed sites. They remain keen to do the latter (Boral says it is up to the landowner to give permission).
Mr Maitland says he’s pleased to hear of the rehabilitation Boral has undertaken at its current site, but stresses the two sites are different.
“The current Rocklow Creek operation has very few significant environmental constraints, but any interference with the catchment of the Minnamurra River is going to have implications for ecosystems identified in State and Federal legislation.
“If it came forward as a new proposal rather than an extension of an existing one, it would require a full EIS.”
Given the importance of the high grade sand to the State’s construction industry, and the resulting price it commands, Boral is keen to have somewhere to go when is existing resource runs out in April/May.
The final decision will be made by the Independent Planning Commission.