More landfill gas migration explosion incidents may now occur as a result of Superstorm Sandy, according to one industry engineer.

The region affected by the severe storm has one of the largest concentrations of old abandoned landfill sites in the world, said waste management engineer Steve Last, who has investigated landfill gas migration explosion incidents, worked for Houston-based Waste Management Inc. and done other consulting.  He said in a news release there are “undoubtedly many thousands of such sites.

“Even if only a few of them could now have become re-activated by an influx of moisture say from flooding, or the erosion of surface capping, and start to emit landfill gas, this could cause a significant risk of injury or even death to those living in nearby properties,” he said.

He says that even landfills that have been long-ago abandoned may contain large areas in which the waste has remained dry and largely preserved and could cause a landfill gas migration explosion. All it needs is water to re-enter the waste and start the waste rotting again, and large quantities of landfill gas will be generated. That creates the hazard.