Canada's Natural Gas Leak

How much methane?

Canada's Invisible Secret

Being invisible doesn't mean it's harmless, the natural gas leak at the Donkin underground coal mine, operating under the waters of the Atlantic Ocean, is of great concern for global, federal, and provincial greenhouse gas emissions.

Cape Breton Island, Nova Scotia
Cape Breton Island, Nova Scotia

Authorities have no real estimate of the total amount of natural gas being released daily or how long it will take to control the gas leak.

Mitigation Failure


Natural gas is mostly made up of 80%–90% of methane, a greenhouse gas that has 25 times the warming power of carbon dioxide.

As per Federal and Provincial environment assessment guidance, without mitigation of fugitive methane emissions, the Donkin Mine would be considered a high emitter of methane gas (one million tonnes CO2e equivalent per year).

Capture and oxidation of methane gas from the mine was never implemented as proposed – a mitigation failure.

The Donkin mine is now closed and idle, there is still no control of unusually high fugitive methane emissions associated with adverse geological conditions caused by gas/rock outbursts.

Canada is now forced to keep the two large ventilation fans at the Donkin mine running indefinitely.

The most potent greenhouse gas, methane, continues to be vented directly into the atmosphere, increasing global warming.

Donkin Coal Mine

Methane emissions from a coal mine occur at a steady state based on actual coal production, but adverse geological conditions such as faults and sandstone strata can be responsible for sudden, potentially dangerous and unusually high methane outbursts.

The Marston Technical Report (NI 43-101), dated 2012, warned authorities about adverse gas and roof conditions associated with the large-scale Flint Flexure (the Donkin Anticline and Donkin Fault) and sandstone strata.

After three years of operation and experiencing 12 rock/gas outbursts within the Harbour coal seam, the Donkin coal mine abruptly ceased operations due to "adverse geologic conditions".


  • Between July and December 2018, a total of six rock outbursts occurred while working the Harbour coal seam. Two were massive gas outbursts, one of which was a third of the size of a football field with corresponding large cavity sizes. All six Donkin rockfalls/gas outbursts went unreported.

  • In December 2018, because of the rock/gas outburst, the Donkin Colliery license was suspended. Partial operations resumed on January 25, 2019, with conditions to provide an updated ventilation plan.

  • May 20, 2019, five months later, still under a prolonged limited mining order the Donkin mine still needed to provide an approved ventilation plan to Nova Scotia's Department of Labour.

  • Just one day later, May 21, 2019, the Donkin mine experienced ignition of methane gas associated with sandstone strata, leading to an immediate stop-work order being issued the next day by Nova Scotia's Department of Labour.

Stop-work orders are issued only in cases of imminent danger to workers.

  • July 2019, the mine experiences another roof collapse and gas outburst while working the Harbour coal seam.

  • One month later, in August 2019, unable to develop a third tunnel as recommended in The Marston Technical Report and in a desperate bid to control the increasing volume of methane gas spilling out of the mine, the Donkin Mine replaced the existing fans with two larger ventilation fans, even foregoing the installation of fan silencers to further increase efficiency of air flow into the mine.

Thus suggesting the volume of methane emissions was exceeding the realistic venting capacity of 250 to 300 cubic meters per second of a single intake tunnel advised by a world class expert on mine ventilation and gas drainage, Dr. Roy Moreby.

Existing Exhaust Tunnel
Methane Exhaust Tunnel

  • February 2020, the Donkin mine was ordered to suspend operations after experiencing two additional rockfall and gas outbursts in two weeks (Feb. 2nd & 13th).

Experts from the United States Mine Safety and Health Administration (MSHA) were to inspect the underground area of challenging geology.

One month later, after only three years of operation, the Donkin underground coal mine abruptly ceased operations on March 30, 2020.

Climate Cassandra

How Large is Donkin Mine Gas Leak?

The Pandora's box has been opened, it's now September 2020, six months after the mine closure, and the ventilation fans are still running twenty-four hours a day, seven days a week, exhausting greenhouse gas at an enormous flow rate of 500,000 cubic feet per minute.

Canadians have no creditable source to provide an estimate of the total amount of gas being released into the atmosphere.

For example, "as of 2018 Nova Scotia Environment (NSE) no longer publicly reports on methane from mining" (see references below).

Third party verification is required to provide all Canadians with transparent and creditable fugitive gas emissions.

Presently, there is no guidance from authorities on how long it will take to control or mitigate the gas leak at the Donkin mine from releasing thousands of tonnes of greenhouse gases into the atmosphere.

That responsibility must be assumed by the Government of Canada.

August 2020

  • CBCL Consulting Engineers. October 2008. Donkin Underground Exploration Volume One Environmental Assessment Report.

  • Marston Technical Report. November 2012. Donkin Coal Project.

  • Mining Science and Technology. March 1990. Modelling of Outbursts at #26 Colliery.

  • Office of the Minister of Nova Scotia Environment. July 2020. eLetter to Brian Comer, MLA Sydney River-Mira-Louisbourg.

  • National Institute for Occupational Safety and Health. June 2006. Handbook for Methane Control in Mining.

  • Per Facie Evidence. 2019 & 2020. Audio Recordings of Adverse Donkin Mine Noise.