Sisson Mine Proposal: An open-pit mine in the heart of upper Nashwaak River valley

Nashwaak River

The Sisson mine project is a proposal to build one of the world’s largest open-pit mines for tungsten and molybdenum in the heart of the upper Nashwaak River valley, near the village of Stanley.

Action Alert, May 11, 2016

Comment on the Comprehensive Study Report for the Sisson Mine

The Conservation Council of New Brunswick is asking its members and the public to submit comments on the federal Comprehensive Study Report for the proposed Sisson tungsten and molybdenum mine. Read the Comprehensive Study Report, the concerns that the Conservation Council has with the report and the Sisson mine and how you can comment here. Copy your comments to Deadline for comments: Sunday, May 15, 2016.

News, May 5, 2016

Desmog: Auditor General Slams B.C.’s Indequate Mine Oversight

Those concerned with the Sisson mine proposal to build a huge tailings dam in the Nashwaak watershed will be interested in the findings of British Columbia’s auditor general on mine oversight in that province. Read the audit here. The audit released in early May states that the government’s oversight on mines is alarmingly inadequate and does not protect B.C. from significant environmental risks. Auditor general Carol Bellringer recommends that the province create an independent agency to manage enforcement and compliance. The government is supporting this recommendation. Bellringer also criticized the adequate financial security deposits that the government requires of the mining companies to cover reclamation costs. The auditor general’s report comes two years after the failure of the Mount Polley tailings dam that spilled 25 million cubic metres of slurry and waste into the pristine Quesnel Lake and surrounding waters.

News, December 3, 2015

On Dec. 3, 2015, the Department of Environment approved the Environmental Impact Assessment submitted by the company behind the project, Northcliff Resources. Read our response to the approval here.

Below you will find recent news about the proposed Sisson Mine and tailings dams. The tailings dam is one of the major concerns with the proposed Sisson mine. The news list is followed by background information about the Sisson mine. 

In the news

Auditor General Report Slams B.C.’s Inadequate Mining Oversight – May 5, 2016

Sisson mine project slammed by aboriginal leaders — Dec. 4, 2015

Big mine project near Fredericton wins environmental approval — Dec. 4, 2015

Sisson mine gets approval with 40 environmental conditions from N.B. government — Dec. 3, 2015

Sisson Mine project given EIA approval, Brian Kenny says — Dec. 3, 2015

ICMM commences global tailings management review — Dec. 2, 2015

Tailings dam failures to continue, experts say — Sept. 9, 2015

Mining industry still horrified by Mount Polley tailings pond collapse: Bennett — Aug. 4, 2015

Sisson mine review raises water treatment concerns — July 16, 2015

Sisson Mine review finds company underestimated costs by millions — July 13, 2015

Sisson mine public consultation nears end — July 10, 2015

Speakers present black and white arguments on proposed mine — June 23, 2015

Sisson mine proposal divides residents, interest groups — June 23, 2015

Sisson mine takes on public concerns in open house meetings — May 28, 2015

Sisson Brook Mine attracts over 600 resumes, but has local village divided — March 25, 2015

Rare artifact at Sisson mine site dates back 8,500 years —March 24, 2015

Northcliff Resources short on money to build Sisson mine — March 23, 2015

Sisson Mine on Information Morning Fredericton — March 16, 2015

N.B. considers St. Mary’s land deal if Sisson mine approved — March 16, 2015

Stanley residents divided over proposed Sisson mine — April 07, 2015



The Conservation Council is an official intervenor for the joint federal and provincial review process for the Sisson mine project.  We hired 11 scientific experts to review the scientific merits of the Environmental Impact Assessment Report in October 2013. The federal Canadian Environmental Assessment Agency is in the process of preparing a report on its findings regarding the environmental and social impacts of the proposed mine.

The experts hired by CCNB identified several key areas of concern, including: gaps in understanding a potential tailings failure into the Nashwaak watershed; impacts to the threatened Atlantic salmon population; impacts to health of mineworkers; and financial costs and benefits of the project.

The Conservation Council presented these and other concerns to the Sisson Mine Environmental Impact Assessment Review Panel in June 2014. During the presentation, Stephanie Merrill, Director of Freshwater Protection, said the proponent has failed to demonstrate that it understands the risks of the project and therefore should not be entrusted with a license to construct and operate the mine. Read her full presentation here.

About the Project

The project has moved slowly since being announced in 2008 and has already switched hands once. Northcliff Resources is the current proponent. The Sisson mine proposal is its only project.

According to available information, the proposed mine would include:

  • 8 km of dams (for perspective, the Mactaquac Dam is 0.5 km long)
  • approximately 87 m dam height at the deepest point (the Mactaquac Dam is 40-50 m high)
  • approximately 145-hectare open-pit, 370m deep (Six hockey rinks could fit in a single hectare)
  • 751 ha tailing impoundment (TSF)
  • 2011 million cubic m. of tailings at maximum storage
  • 181 million cubic m. of waste rock and stored ore.
  • A tailing impoundment volume of 350 million cu.m.
  • Capture of all precipitation from 800-900 ha for 27 years
  • 30,000 tons of ore processed daily for 27 years
  • An additional 30,000 tons of waste rock generated daily for 27 years
  • The mine would require at least $579 million in capital investment
  • The company claims 500 jobs during the two year mine construction.
  • The company claims 307 total jobs at startup

Find more details on the Sisson Mine proposal here.

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