A coalmine has cracked the rock above it and methane gas is now bubbling through one of Sydney’s key drinking water catchments.
The mine, in the Waratah Rivulet, east of Campbelltown, is owned by a subsidiary of the world’s biggest coal company, Peabody.
The Sydney Morning Herald is reporting that the ground under the river has cracked as a result of the mine and methane gas is now leaking out.
”It will probably take three to four months to stop,” a spokeswoman for Peabody, Jennifer Morgan, told the Herald.
”Look, this is a completely natural occurrence in the vicinity of coalmines.
”There is no toxicity and we are sure we are in compliance with our environmental requirements. We are monitoring it closely.”
Catchment authority officers visited the site last week, joined by environmentalists and a scientist, after the leak was reported by the Sydney Catchment Authority.
Photographs show methane gas bubbling to the surface, creating bright-coloured algae in the water, but according to authority chief executive Michael Bullen, the leaks pose no risk to human health and there is little chance of large algal blooms downstream in the Woronora Reservoir.
"The SCA is working closely with the Department of Planning to address the issues identified," he said.
It has also written to Peabody Energy seeking further information.
Environmentalists are outraged by the incident, and say this is not the first time there have been similar issues at the site.
”It’s outrageous that, six years after the rivulet was first damaged by coalmining, this damage continues to happen,” spokesman for Total Environment Centre, Dave Burgess said.
Six years ago, a two-kilometre stretch of the Waratah Rivulet ran dry due to drought and combined with cracking of the river bed, methane leaks occurred.
”We’d like to see a trigger mechanism where mining stops when damage reaches an unacceptable level.”
He said the methane plume was visible from the river bank, and action must be taken.
Longwall mining has caused significant cracking in bedrock under the river.
Morgan said Peabody is attempting to solve the problem by gluing the broken river back together, using polyurethane to fill the cracks between shattered rocks.
”It’s probably about six months behind schedule … but that is purely because there has been a lot of heavy rain and the river has been flowing,” she said.
”But it shows we are serious about fixing any damage.”
Image: The Nature of Robertson, blog.