Some may ask why has it taken so long for this work to be done? After all, the risk that this legacy contamination posed to the environment has been known for decades.

Part of the answer to this question must lie in the change in community attitudes towards industrial pollution. 

The arsenic disposal pit was used from 1969 to 1994 to dispose of liquid and solid by-products of the ammonia production process. 

It seems horrifying by today’s standards but the original pit remained unsealed until the mid-1980s. 

There are many other examples of industrial processes that were commonplace at Hunter workplaces only a few decades ago that would be considered major health and environmental risks by today’s standards. 

While these processes have largely faded into history, their pollution legacy looms large. 

Millions has been spent containing pollution left from the former BHP steelworks site at Newcastle.

Likewise the toxic legacy from the former Pasminco lead smelter at Boolaroo continues to impact on the surrounding community 15 years after the smelter’s closure.

Orica inherited the arsenic legacy when it took over the Kooragang Island plant in 2003. 

About 15,000 tonnes of the material has already been removed from the pit, however, a suitable method of dealing with the remaining contamination has been difficult to identify.

In the meantime, groundwater modelling has shown the pollution is inching closer to the south arm of the Hunter River. 

Years ago a ticking time bomb scenario such as this may not have caused alarm among regulators and the majority of the wider community.

However when today’s standards are applied the prospect of arsenic, regardless how little, entering into the Hunter is unacceptable.

The 12 meter deep containment cell may seem like an extreme solution but it is necessary to safeguard the environment from the toxic legacy of yesteryear. 

Issue: 39,000