12.09.2008

High levels of methane gas migrated from a closed landfill into a neighbouring housing estate at Cranbourne, south-east of Melbourne.

Dangerous levels of gas were detected in separate homes in confined areas such a wall cavity and under a kitchen sink. Concentrations of methane were also detected in confined spaces such as pipes and stormwater pits surrounding the estate.

C.F.A. Assistant Chief Fire Officer Stephen Warrington warned of a "very real risk" of explosion. Warrington was quoted as saying the situation was “quite unique for Australia and most of the world. We don't know the ramifications of it".

Some residents claimed they experienced headaches after entering their homes without ventilating the area continuously.

Whilst the gas has been reported as methane, workers and residents in the effected area would be well advised to check for contamination from volatile organic compounds, (VOC’S). Methane, whilst flammable and explosive, is a colourless odourless, non toxic gas. VOC’s on the other hand, can be flammable and explosive, toxic in extremely low concentrations, and more likely to produce the signs and symptoms experienced by residents such as headaches etc. VOC's are not typically detected by the common monitoring systems on the market.

In addition to the health and safety risks concerning residents, this event highlights the importance for workers in confined spaces to be diligent and to never drop their guard to the risks of gases. It also highlights the importance of correct environmental monitoring practices - even in passive areas such as storm water drains or pits.