Soil contamination linked to combustion

An underground fire may be responsible for gas emissions detected in soils south of Chinchilla.

Questions have been raised about soils contaminated with carbon monoxide, hydrogen and hydrogen sulphide at two metres depth detected by Queensland’s Department of Environment, which has not ruled out underground coal seam fire as a potential cause.

The gases are regarded as explosive in sufficient concentration, and the department has warned property owners in an area of approximately 314 square kilometres south of Chinchilla to contract the department prior to any excavation or soil disturbance which occurs at two metres or deeper.

"Given the nature of the gases found, [the department] cannot rule out an underground fire as a cause, however at this early stage of the soil sampling, [the department] has not been able to determine the actual source or cause," the department said in a statement to ABC.

"These are preliminary results, and until further testing is conducted EHP cannot confirm the extent of the impacted area.”

The ABC questioned the proximity of the experimental Linc Energy underground coal gasification plant, however a spokesperson for Linc Energy said it was not possible for their operations to cause a fire.

Linc Energy’s plant sits close to the southeast border of the warning zone issued by the department, and has been in a decommissioning phase since 2013.

“As yet the department have only released preliminary results, they still haven’t told us what or where they found anything,” a spokesperson for Linc Energy said.

“We’ve still got monitors in the ground, we’re still monitoring air soil and water, we know for certain that those gases have not come from our site.

“Personally, the Company’s management also find it extremely curious that based upon “preliminary results” alone, including the methane (CH4) detection that we were advised of by the Department in our telephone conversation (but did not appear in its public release), that the Department immediately and publically discounted the extensive on-going Coal Seam Gas (Coal Bed Methane) operations in the region as a possible cause.”

Linc Energy said the UCG and CSG industry pursued the same type of tight coal seams, and that the Linc plant had exhausted it's underlying resource for syngas production.

The USG process turns coal into syngas via a process which pumps steam and oxygen into a coal seam and begins a combustive chemical reaction.

Linc Energy said it was not possible for that process to lead to further combustion once oxygen reserves had been exhausted.

Lock the Gate’s Drew Hutton said the government must immediately halt all CSG and UCG exploration until it can determine the extent and cause of the fire.

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