Tulsequah Mine Information

The Tulsequah Chief mine, located 100 km south-west of Atlin B.C., is a historic copper/lead mine which operated from 1951 to 1957. The mine site is on the Tulsequah River about 10 km upstream from its confluence with the Taku River, located in the traditional territory of the Taku River Tlingit First Nation (TRTFN).


The mine is currently owned by Chieftain Metals Ltd. (Chieftain), who acquired the property, and a Mines Act permit for limited construction works associated with the first phase of mine re-development was amended in 2011.

Chieftain undertook exploratory drilling, a feasibility assessment, and constructed and operated an interim water treatment facility for three months, after which construction at the mine site was suspended, and the mine was shifted into care and maintenance status.  On September 6, 2016, Chieftain was placed into receivership.

In a hearing on August 11, 2020 before Chief Justice Morawetz in the Ontario Superior Court of Justice, the Government of B.C. and TRTFN argued for an end to the receivership process.  On October 8, 2020, the Chief Justice released his decision wherein he discharged the receiver and authorized Chieftain’s primary secured creditor to bring a motion no later than August 11, 2022 to seek the re- appointment of the receiver.  In the interim, the B.C. government will continue to pursue the options available to it to progress toward site reclamation.

Works on Site Summer 2020 

Working collaboratively with the TRTFN and the Government of Alaska, the Government of B.C. released a conceptual closure and reclamation plan for the Tulsequah Chief Mine in August 2020.  The closure and reclamation plan outlines a phased approach that involves a series of steps designed to reduce the ongoing contamination.  It is designed to be flexible, so changes can be made once more information is gathered from the site.

Some of the first steps include repairing bridges, upgrading the access road, establishing an erosion protection berm and repairing the existing airstrip. This work is required to prepare the site in order to address environmental, health and safety issues and undertake long-term remediation.  The Government of B.C. committed $1.575M toward these initial activities in 2020 and, working collaboratively with the TRTFN, undertook initial physical works required to rehabilitate the site for future reclamation efforts.  Approximately 25 local residents were employed by the Atlin Tlingit Economic Limited Partnership to work on the site over the summer.  The TRTFN are also involved in the multi-year aquatics monitoring program.  An initial assessment of water treatment plant functionality is ongoing.

Issues of Concern

The Tulsequah River is the primary receiving environment of mine effluent. Except for a short period of time in 2012, when Chieftain Metals operated the interim water treatment facility, untreated acid mine drainage has been discharging into the Tulsequah River since at least 1957.

Acid mine drainage, also referred to as acid rock drainage, refers to the outflow of acidic water from metal or coal mines. The acid drainage is created when naturally occurring sulphide minerals in the mined rock and waste rock are exposed to air and water. This process can go on for many years, creating potentially serious environmental issues.

In October 2016, the Alaska Department of Fish and Game released a report on Tulsequah Chief Acid Mine Drainage and Dolly Varden Char Whole Body Metals Concentrations that showed no significant difference in metal concentration in fish captured near the mine site compared to fish captured upstream and downstream.

In 2014, Chieftain Metals Corp., at the request of the Ministry of Environment, undertook a comprehensive Aquatic Ecological Risk Assessment which found there had been no unacceptable risk to the Tulsequah River from their discharge during times of the year that are critical for salmon. In 2017, a further Aquatic and Ecological Risk Assessment was undertaken by the B.C. Ministry of Environment and Climate Change Strategy.  This additional study was undertaken in an effort to assess ongoing concerns being raised regarding transboundary impacts from the mine site. This report demonstrated that aquatic effects while concentrated adjacent to the mine site attenuated further downstream, with no detectable impacts to water quality 2km downstream of the mine site – see link below.

Key Inter-Ministry Actions

The Ministry of Energy, Mines and Petroleum Resources works closely with the Ministry of Environment and Climate Change Strategy to manage risks associated with the site.

Shortly after Chieftain was placed under receivership, on September 26, 2016, inspectors from the Ministry of Energy, Mines and Petroleum Resources, the Ministry of Environment and Climate Change Strategy and a member of the Taku River Tlingit First Nation inspected the Tulsequah Chief mine site. Inspectors found a number of non-compliance issues at the site including no caretaker on site, drainage and maintenance issues at the sediment pond, and unsecured storage of chemicals.

The Ministry of Energy, Mines and Petroleum Resources hired a contractor to properly secure all chemicals identified on site. This work was completed in December 2016. Physical works were carried out at the site in 2017 to mitigate risks at the exfiltration pond.

Compliance & Enforcement

Environmental Management Act:

On May 11, 2012, the Ministry of Environment (ENV) issued an Advisory for the accidental release of mine water. This was followed by a Warning issued for an unauthorized bypass of the water treatment plant on July 24, 2012, and subsequently a Notice of Non-Compliance for a sludge pond seep on December 6, 2012. Further advisories of non-compliance were issued on January 16, 2013 for not monitoring in accordance with the Discharge and Receiving Environment Authorization Amendment, and on October 15, 2015 for an unauthorized bypass of approved works.

On October 24, 2016, ENV referred Chieftain Metals to the Conservation Officer Service (COS) for an investigation of non-compliance with an unauthorized bypass of the Interim Water Treatment Plant, which resulted in the unauthorized discharge of toxic effluent.  On August 27, 2017, Chieftain Metals was again referred to the COS for investigation of an unauthorized bypass of the Interim Water Treatment Plant, failure to maintain authorized works, not submitting discharge and receiving environment monitoring results, and not submitting their annual report.

Mines Act:

On September 26, 2016, the Ministry of Energy, Mines and Petroleum Resources’ Deputy Chief Inspector of Mines conducted an inspection at the site. On October 24, 2016, inspection orders were issued pursuant to section 15 (4.1) of the Mines Act for non-compliance with section 21 of the Mines Act and section 10.1.5 of the Health, Safety and Reclamation Code for Mines in British Columbia (the Code).

As neither Chieftain nor its Receiver has complied with the Deputy Chief Inspector of Mine’s orders issued on October 24, 2016, the Chief Inspector of Mines escalated enforcement action on July 4, 2017 by issuing orders under Section 35 of the Mines Act.  A further order was issued on October 27, 2017 further identifying non-compliance with part 10.7.20 of the Code regarding failure to implement remediation strategies to address water quality impacts to the receiving environment, as well as permit conditions pertaining to protection of the land and watercourses. The orders required Chieftain and/or its Receiver to immediately prepare and submit a plan to re-establish compliance in relation to the issues identified in the previous inspection report - see link below.  

Chieftain’s primary secured creditor retained an environmental consultant to review existing data and develop a set of remediation concepts for the mine, which was submitted to the Province in February 2018.  The remediation plan that was submitted did not adequately address the requirements set out in the orders. Key omissions included: management of sludge produced from the interim water treatment facility, timelines and costing for remedial actions.  An October 2018 deadline was provided to allow Chieftain to meet these requirements. The outstanding information was not submitted by this deadline.  

In response, the Ministry of Energy, Mines and Petroleum Resources issued a Request for Proposals for the development of a remediation and closure plan for the site in November 2018. The Request for Proposals specified that the final report must include: a site hazard assessment; a risk analysis; clear identification of various remediation methodologies for each mine component; and a detailed estimation of costs to implement the remediation activities.

In response, the Ministry of Energy, Mines and Petroleum Resources issued a Request for Proposals for the development of a remediation and closure plan for the site in November 2018 and issued a Notice of Escalating Enforcement Action to Chieftain in December 2018 – see link below.

Remediation Plan

In January 2019, representatives from the Ministry of Energy, Mines and Petroleum Resources, the Ministry of Environment and Climate Change Strategy, and representatives of the Taku River Tlingit First Nation participated in a collaborative Request for Proposals review process. All parties arrived at a consensus recommendation and SNC-Lavalin in partnership with SRK Consulting was awarded the contract. Throughout 2019, these contractors undertook data gap analysis and site visits to gather soil and water samples, conduct an inventory of existing hazards on site, undertake a more thorough review of existing mine portals and underground workings and contamination pathways.  Multiple technical workshops took place throughout 2019 to review remedial options. Participants in the workshops included from the Taku River Tlingit First Nation, Teck Resources and the Alaska Department of Natural Resources.

A final version of the plan was submitted to the Province in April 2020 – see link below.

Receiver Discharged

On October 8, 2020, Ontario Superior Court Chief Justice Morawetz released his decision to discharge the receiver www.canlii.org/en/on/onsc/doc/2020/2020onsc5161/2020onsc5161.html.  Justice Morawetz approved the discharge of the receiver and authorized Chieftain’s primary secured creditor a limited time to bring a motion to re-appoint a receiver.  Any such application to re-appoint a receiver in the proceedings must be made no later than August 11, 2022 and on notice being provided to the Province. The Ministry will continue to review and pursue relevant legislative options available to the Province in the intervening period.

Immediate Actions on Site

B.C coordinated activity on site for Summer 2020 to conduct physical works and to undertake additional studies to address data gaps. This work is being carried out to address environmental, health and safety issues and to prepare the site for long-term remediation. The physical works that were successfully undertaken in late 2020 included road repairs, establishing a functional camp, transporting fuel/supplies to site for next year’s field season and partial bridge repairs.  Larger bridges and the airstrip require detailed engineering prior to repair, as the damage to these structures is extensive. The LiDAR survey was not undertaken in the 2020 season due to weather restrictions. Once completed, the survey will provide topographic information to support further design. That survey along with the multi-year aquatics monitoring program, and a desktop assessment of the possibility of short-term use of the interim water treatment plant will be taken up in the spring of 2021. 

Reports & data

Ministry of Energy, Mines and Petroleum Resources (MEMPR)*

*Previously (Ministry of Energy and Mines)

Ministry of Environment and Climate Change Strategy (ENV)

Environmental Assessment Office

State of Alaska Reports

B.C.-Alaska Water Monitoring Program

Tulsequah Chief Mine Closure and Reclamation Plan