Toxic waste: a burning problem


By Simon Divecha

SYDNEY — Last week the New South Wales government quietly gave the go-ahead to a major new hazardous waste disposal facility. The government is pushing ahead with a $15 million expansion of the Lidcombe Waste Treatment Plant regardless of community and environmental objections.

The development has been approved despite Lidcombe's current operating record. The plant has been fined recently for toxic waste leakage from a truck, notices have been issued for breaches of the Clean Air Act, and prosecution is under way by the Environment Protection Authority for alleged illegal emissions.

In November 1995, Sydney Water ordered the waste plant to stop discharging to the sewer after cadmium, a toxic metal, was detected. Environmental studies conclude that the plant fails to meet a NSW Environment Protection Authority odour goal 99.5% of the time.

The expansion is under way because of a commitment to shut the controversial Castlereagh toxic waste landfill by the end of this year. Under the new plan, toxic waste that used to be dumped in Castlereagh will be solidified at Lidcombe.

Initially the waste is to be sent to an ordinary solid waste landfill; within two years, it is intended to incinerate the waste in power stations or cement kilns.

Every year some 100,000 tonnes of liquid hazardous waste is sent to the Lidcombe plant. The plant used to turn this waste into sludge and then send the toxic sludge to Castlereagh.

The trouble with this is that all landfills leak, so if the waste is still toxic when the landfill starts leaking, people and the environment are put at risk. Many toxic chemicals can remain dangerous for decades, well past the life of landfills.

When Castlereagh shuts, there will be no hazardous waste landfills left in NSW. Earlier this year, the definition of hazardous waste was changed. The new definitions mean that if waste only leaks slowly into the environment and contains certain levels of chemicals, it can be classified as non-hazardous. But slow-leaking toxic chemicals are still dangerous.

The new classification system ignores the fact that some toxic chemicals can also escape from waste as gas. Gases containing cancer-causing chemicals can in many cases be measured in the air at the landfill boundary. Another study has found potential for exposure of residents near a landfill with chemicals at levels of concern.

The solidified toxic waste from Lidcombe is expected to have high enough chemical levels to be classified as hazardous. However, with the closure of Castlereagh, approval will probably be given to dump the solidified waste in an ordinary landfill. Potential sites are located at Eastern Creek, Belrose, Jack's Gully, Lucas Heights and Marsden Park.


The proposed long-term solution is to incinerate this waste, and if the incineration project does not proceed, the waste will continue to be dumped in existing landfills.

Incineration is a flawed technology that is unacceptable to the public. It was rejected in the early 1990s with the stopping of a proposal to build a high-temperature incinerator to burn intractable waste. Recently the Waterloo garbage incinerator has also been shut.

Although government documents recognise that incineration will not be accepted by people in NSW, the state will get this flawed technology by default. The toxic waste will be burnt in power stations or cement kilns — avoiding the need to build a dedicated incinerator and the community opposition to such a development.

The idea of burning toxic waste in cement kilns is not new. It results in the emission of toxic chemicals.

The levels of chemicals coming out of the kiln can be quite substantial. A trial burn of hazardous waste at a North American kiln resulted in a 167% higher emission of heavy metals, including a six times greater emission of lead and 11 times more zinc.

The kiln also produced dioxin, one of the most toxic chemicals known. Dioxin emissions increased by eight times, and many other unidentified compounds were also produced.

There is no doubt that the current toxic waste landfill at Castlereagh should be shut. However, the assessment of likely environmental impacts from the alternative plan is deeply flawed.

One of the significant failures of the government's environmental assessment process is that it does not really look at important problems you would expect from burning waste.

The assessment tries to look at the impact of burning waste in a power station. To do this, it assumes that all oil-based chemicals will be destroyed in the power station. An assumption like this would not be made even for a dedicated high-temperature toxic waste incinerator.

The government studies also manage not to include or refer to results from an Australian power station that conducted a trial burn of waste oil with coal. These results found that surprisingly high levels of some toxic chemicals were produced.

Power stations burning the hazardous wastes will also release toxic chemicals in the ash from the plant. The environmental study shows that when a power station releases water containing ash into a dam, some heavy metals would increase by 50 to 3000%. The study does not attempt to look at the impact of this.

This development is also contrary to many state government policy aims and its own legislation. NSW legislation aims to reduce by 60% the amount of waste disposed of in this state.

To do this for liquid hazardous waste needs strong programs to cut waste generation. But documents associated with this development predict a major increase in waste generation.

Currently the waste treatment plant produces about 20,000 tonnes of wet residue a year. This is expected to increase by more than 50% within 10 years.

If the waste is turned into solid blocks, it is expected that 80 tonnes per day would be sent to a solid waste landfill. This is predicted to rise to an average of 120 tonnes a day beyond the year 2008.

The laws commit the state to managing waste first by avoidance, then reuse, recycling and reprocessing before disposal. This plan looks only at how to dispose of the waste once it has been produced. There are no recommended actions for avoiding the generation of waste in the first place.

Expansion of the Lidcombe plant is being fast-tracked. Even before the government's assessment of environmental impacts was complete, it was looking for tenders from companies to build the plant.

It is very unlikely that people in NSW will accept incineration of toxic waste in any form, which leaves the government with an expensive development and very few options. The alternatives are waste reduction, minimisation and avoidance, comprehensive clean production programs and strategies to eliminate toxic chemicals at source and remove them from the production cycle.