TOXIC ASH FROM GARBAGE DUMPS

Dr Aline K. Wong asked the Minister for the Environment what steps his Ministry is taking to ensure that the ash from incinerated garbage which is dumped in landfills does not contain toxic substances.

The Senior Parliamentary Secretary to the Minister for the Environment (Mr Eugene Yap Giau Cheng) (for the Minister for the Environment): Sir, I am answering on behalf of my Minister.

Mr Speaker, Sir, incinerator ash contains toxic substances especially heavy metals such as cadmium, chromium and nickel. These heavy metals are present in trace quantities in domestic as well as industrial refuse, and are left behind in the ash after incineration. Although we do not allow certain types of industrial waste, such as sludge and chemical wastes to be incinerated as they are known to contain a high proportion of heavy metals, it is not possible to segregate domestic waste as even waste such as wood and paper contain traces of heavy metals. Hence, like other developed countries that employ incineration, our ash also contains heavy metals.

These heavy metals are toxic if ingested through the food we eat or the water we drink. It is important that our food and water are not contaminated by incinerator ash.

In Singapore, the ash from our incineration plants is dumped in controlled landfills located outside our water catchments. There is therefore no possibility that our water supplies could be contaminated with incinerator ash. Tests of our water quality confirm this to be true.