Mine Closure and Post Closure

Reclamation Monitoring & Reporting

After a mine closes, reclaimed lands may raise new environmental problems due to, for example:

  • weathering of pyritic wastes, which may produce acidity and release toxic metals;
  • decomposition of organic amendments, which releases metals previously held in stable organic complexes;
  • depletion of nutrients required for re-growth;
  • occurrences of extreme weather conditions that may affect site stability; and
  • upwards migration of acidity, heavy metals and salts that may affect ground surface conditions.204

In addition, although the removal of mine water generally ends at mine closure, underground mines often fill, leading to the release of contaminated mine water through adits or fractures that reach the ground surface.205 Adequate post-closure environmental monitoring is therefore essential to ensure that local communities and ecosystems are protected from the effects of former mining activities.

Overview of BC Law

Under BC mining law, miners must carry out monitoring programs, as required by the Chief Inspector, to demonstrate the achievement of reclamation and environmental protection objectives, including land use, productivity, water quality, and stability of structures.206 Every year, miners must submit to the government a summary report containing environmental protection and monitoring programs of reclamation and environmental monitoring work performed.207 This annual reclamation reporting must be in a form specified either by the Chief Inspector or in a mine permit condition.208 The form and content requirements for these annual reclamation reports are set out under provincial policy, and include the following:209

  • Mining program: Surface development to date, over the past year, and projected over next five years.
  • Environmental protection and reclamation program: Summary of areas disturbed and reclaimed and descriptions of various matters including: waste dump reclamation; re-vegetation; invasive plant management; metal uptake in vegetation; road and watercourse reclamation; existing and proposed Metal Leaching/Acid Rock Drainage (ML/ARD) prevention; control and treatment methods; and drainage and other environmental monitoring programs.
  • Future reclamation programs: Description of the nature of the reclamation program and research activities planned for the coming year and a 5-year projection of anticipated mining and reclamation.
  • Reclamation liability cost estimates: Detailed estimate of the total costs of outstanding reclamation liabilities over the mine life, including long-term costs of monitoring, maintenance and water treatment.

At mine closure, miners must carry out a program of site monitoring and maintenance.210 When a mine requires on-going post-closure management, the miner must submit a closure management manual that describes the mitigation, monitoring and maintenance requirements and tracks important changes that effect long-term mitigation, monitoring and maintenance requirements.211

Provincial policy expands on the matters for which long-term monitoring may be required, namely: “geotechnical, ML/ARD, re-vegetation, sedimentation or other requirements depending upon the site and closure plan”.212 In addition, provincial policy states that the mine permit application should include details on the means by which environmental protection and quality control will be achieved during all stages of reclamation, including details of the authority and reporting sequence of any environmental staff and the procedure for providing reports and updates to government agencies.213

As indicated in the following Recommended Solutions, stronger legal requirements for reclamation monitoring and reporting are provided in other jurisdictions.


Although BC law requires reclamation monitoring and reporting, additional legal requirements would enhance both mitigation efforts and accountability.

Recommended Solutions

Set clear legal thresholds for action in reclamation monitoring program

[Tags: Reclamation Plans; Monitoring]

A monitoring program that does not include clear thresholds for action threatens the adequacy of environmental protection at closed mines. These thresholds should automatically trigger clean-up efforts where environmental standards are exceeded. In Nunavut, the importance of clear thresholds has been recognized by way of government policy.214 This has also been recognized in the Mine Site Reclamation Policy for the Northwest Territories, which states that “for a monitoring program to be meaningful, it must include provision for appropriate progressive responses which trigger action whenever exceeded, including the establishment of thresholds or the identification of changes in circumstances.”215

Mandate the inclusion of a monitoring schedule in post-closure environmental program plan

[Tags: Monitoring; Post-Closure; Enforcement]

A post-closure environmental program should have a clearly defined and enforceable monitoring schedule. In Saskatchewan, applications for approval of decommissioning and reclamation plans must set out such a schedule. Applications must also include time frames for “monitoring the mining site for physical and chemical stability and for detecting spills or the release of pollutants during and after decommissioning and reclamation”.216

Mandate monitoring of vegetation and animal tissue for metal uptake

[Tags: Monitoring; Vegetation; Metal Uptake]

Metal uptake in vegetation (including lichen)217 and animal tissue is a potentially significant concern in areas disturbed by mining activities. The potential for metal uptake in vegetation is in part recognized under BC law, which requires monitoring of vegetation for metal uptake “when required”.218 Ecological risk assessments are also contemplated, but are only mandatory when required by the Chief Inspector.219 Further, where a significant ecological risk has been identified, BC law mandates that “reclamation procedures shall ensure that levels are safe for plant and animal life and, where this cannot be achieved, other measures shall be taken to protect plant and animal life”.220 It is unclear what constitutes “safe levels” and what is meant by “other measures.” Again, much of the language is broad and discretionary and leaves gaps, including:

  • No mandatory requirements to monitor vegetation for metal uptake;
  • No requirements to monitor animal tissue for metal uptake;
  • No clarification on what vegetation or animal tissue is to be monitored;
  • No criteria for establishing whether or not there is a significant ecological risk (this determination is left to the Chief Inspector’s discretion);221
  • No requirements to consult with local communities or First Nations on their consumption of local vegetation and animal tissue; and
  • No requirement to protect human health from consumption of vegetation or animal tissue.

In sum, BC’s laws provide little guarantee that potential metal uptake will be considered in re-vegetation efforts. In contrast, under Northwest Territories’ policy, the potential health concerns related to metal uptake in vegetation and animal life are recognized by requiring that re-vegetation be completed with “indigenous vegetation not used by wildlife or people if uptake of metals is a concern”.222 Notably, this is a policy, and not a legal requirement. Nevertheless, it highlights an important issue in the selection of appropriate plants for re-vegetation; an issue that can have long-term impacts on the post-closure land use of lands previously disturbed for mining activities.

Mandate the online posting of annual reclamation reports to simplify public access

[Tags: Reclamation; Public Consultation]

Simplifying data access by posting reclamation reports online helps promote transparency. This is recognized in Alberta where companies have been required to submit digital conservation and reclamation reports, with data on costs exempt, since 2009.223

Mandate environmental audits to evaluate results of post-closure environmental monitoring

[Tags: Environmental Audits; Post-Closure; Monitoring; Enforcement]

Audits are important tools for evaluating the post-closure environmental monitoring program. The BC government has recognized this for the forest industry, which is subject to random environmental and fiscal audits by the Forest Practices Board; a tribunal established to provide monitoring, enforcement, and oversight to forestry practices in BC.224 At present, however, no similar requirement is imposed on the mining industry in the province.

Mandate independent review of the adequacy of site reclamation

[Tags: Review; Reclamation]

An independent review to assess the success of site reclamation creates a more transparent process. This is recognized in the state of Victoria (Australia), where the regulatory authority is empowered to require miners to “engage an auditor to certify that land has been rehabilitated as required”.225 In addition, an independent consultant’s report must show that future risks have been managed to a level satisfactory to the regulatory authority.226

Require reference to annual reclamation reports to encourage adaptive management of closure plans

[Tags: Reclamation; Closure Plans; Evaluation]

Annual reclamation reports are useful adaptive management tools that should be used to evaluate the level of success that reclamation activities have had towards achieving closure objectives. These reports can be invaluable in determining whether closure plans should be amended to address previously unforeseen problems. This is recognized in Manitoba, where the law requires that annual reclamation reports include “an evaluation of whether or not the approved closure plan is adequate to properly rehabilitate the site”.227

Learn About Mining

Problems and Solutions


A Community Resource