On 17 April 2013, FoMH members joined other community representatives for an inspection of the civil works being undertaken by the Commonwealth at the northern base of the Anzac Rifle Range section of Malabar Headland.

The purpose of the works is to trap and treat the contaminated leachate and groundwater that seep out of the landfill beneath the rifle range on Malabar Headland. Until now this leachate/groundwater has flowed into Randwick City Council’s South Maroubra stormwater channel and contributed to the pollution of South Maroubra beach, including the children’s rock pools.

A slotted agricultural collection pipe, located 6-8 metres underground on bed rock in a lined trench, will trap the leachate/groundwater before it can merge with the stormwater.

Randwick Council’s stormwater pipe crosses the path of the leachate capture trench and drain, adding to the compleity of the project

Randwick Council’s stormwater pipe crosses the path of the leachate capture trench and drain, adding to the complexity of the project

A pump facility will pass the collected leachate/groundwater through a filtration system that will extract ammonia and then transfer it into the existing wetland and reed beds. There the leachate will settle, be diluted with surface water, and by means of the natural action of the reed beds, be stripped of most of its remaining significant pollutants such as heavy metals.

An outlet channel will allow treated residue – mixed with surface water and relatively clean and free of pollutants – to flow out to sea well to the east of the children’s pools.

In the longer term it is intended that the leachate/groundwater will be pumped from this area up on to the rifle range and into a large settling pond, to be located in the vicinity of the former riding school. Wetlands will be constructed there, to provide natural filtration and a habitat for birds and other wildlife.

The current program of works is being undertaken by environmental engineering contractor Enviropacific and will be finished and fully operational by 30 June.

This complex and expensive environmental engineering project has been commissioned by the Commonwealth Department of Finance and Deregulation (DoFD) which manages the land, and is funded entirely by the Commonwealth. The capital cost of the works is being met from a $2 million allocation for remedial works on Malabar Headland in 2012-13.

The project represents a substantial, long term investment by the Commonwealth in a thorough and best practice rehabilitation of Malabar Headland following many years of environmentally insensitive use as a landfill site.

General view of the works area looking eastward

General view of the works area looking eastward

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