Mine Closure and Post Closure

Reclamation Standards for Re-Vegetation, Growth Media and Metal Uptake

Overview of BC Law

BC law states that reclamation must be completed as follows:

  • Land must be reclaimed to a state that matches the average land capability that existed before mining;121
  • Land that is re-vegetated must be returned to a “self sustaining state using appropriate plant species”;122
  • Growth medium on all re-vegetated land must “satisfy land use, capability, and water quality objectives”;123
  • All surficial soil materials removed for mining purposes must be saved for use in reclamation programs (with exceptions allowed;124
  • Metal uptake by vegetation must be monitored (when required);125
  • Ecological risk assessment for metal uptake (when required by the Chief Inspector);126 and,
  • If the above assessment identifies significant risk, the site must be made safe for plant and animal life by reducing the levels of metal uptake by vegetation. If it is not possible to reduce the metal uptake to a safe level, “other measures shall be taken to protect plant and animal life”. 127

There are also various guidelines for site re-vegetation under BC government policy.

These include recommendations that a re-vegetation plan be developed based on specific information  such as: regional plant succession patterns; final site productivity; species objectives; soil characteristics; and, a review of results of other reclamation work in the area.128 Provincial policy also recommends that the reclamation plan consider the development of vegetation. This must be supported by information on soil conditions, land use objectives, natural plant succession and the plant species the miner plans to establish.129

Although BC’s approach is notable, greater detail and more specific legal requirements for re-establishing natural successional trajectories and processes (such as nutrient cycling and soil formation) have been adopted in other jurisdictions, as described below.

Issue

BC reclamation standards for re-vegetation can be strengthened to ensure that sites are restored to self-sustaining ecosystems.

Recommended Solutions

Establish measurable and enforceable criteria to determine if ecosystem restoration goals have been attained

[Tags: Ecology; Restoration; Enforcement]

Optimum site rehabilitation entails soil re-development and habitat reconstruction that restores ecosystems rather than merely establishing monoculture vegetation.130 This is partially recognized under BC law, which requires that lands disturbed by mining activities be re-vegetated “to a self-sustaining state”. The meaning of “state”, however, is not defined and therefore does not explicitly mean restoration of habitats and ecosystems.131 In contrast, the 1994 Whitehorse Mining Initiative recommendation that mine sites be returned to “self-sustaining ecosystems that are compatible with a healthy environment and with human activities”132 places greater emphasis on the importance of establishing important biological processes than merely re-establishing basic vegetation.133

Other jurisdictions have enacted laws that more effectively adopt the Whitehorse Mining Initiative’s  recommendation. For example, US federal law requires that “a diverse and permanent vegetative cover capable of self-regeneration and plant succession and at least equal in extent of cover to the natural vegetation of the area” be established on affected areas.134In California, the concept of a ‘self-sustaining state’ is also clearly described. There, the vegetative cover must be “capable of self-regeneration without continued dependence on irrigation, soil amendments or fertilizer”.135

Conserve topsoil through: salvaging; measures to prevent erosion, weeds and contamination; and specified time limits for removal

[Tags: Reclamation Plans; Conservation; Vegetation; Overburden; Topsoil]

Topsoil conservation is another key consideration for achieving successful site re-vegetation. This precaution helps conserve nutrient-rich soils, restore native site vegetation, and reduce costs and greenhouse gas generation associated with imported growth media. As mentioned above, BC law mandates that the growth medium on all re-vegetated lands satisfies land use, capability, and water quality objectives, 136 and that “all surficial soil materials removed for mining purposes shall be saved for use in reclamation programs, unless these objectives can be otherwise achieved.”137 Provincial policy also recommends that plans for erosion control, sediment retention and soil handling be included in reclamation programs.138 However, as policy rather than law, these latter requirements are not legally enforceable.

More stringent legal requirements have been adopted in other jurisdictions. For example:

  • Washington State law requires reclamation plans to include specific plans for topsoil conservation.139
  • Colorado state law requires topsoil removed during mining activities to be segregated from other soil.140 Colorado law also requires that where “topsoil is not replaced on a backfill area within a time short enough to avoid deterioration of the topsoil, vegetative cover or other means shall be employed so that the topsoil is preserved from wind & water erosion, remains free of any contamination by other acid or toxic material, and is in a useable condition for sustaining vegetation when restored during reclamation”.141
  • Yukon law requires exploration activities to be carried out by removing the vegetative mat ” so as to protect the seed and root stock contained within the mat” and storing it “separately from any  or bedrock removed” so that it can be used” in re-establishing the vegetative mat when the exploration program ceases”.142
  • South Dakota State law requires specific means to be employed to protect topsoil from wind and water erosion, and contamination. These means must ensure that the topsoil is in a “useable condition for sustaining vegetation when restored during reclamation.”143

California requires that both topsoil and suitable growth media stockpiles be planted with a vegetative cover, or be protected by “other equally effective measures to prevent water and wind erosion and to discourage weeds”.144 California law also mandates other specific performance standards for topsoil salvage, maintenance and redistribution. For example, topsoil must not be removed earlier than one year before mining activities disturb a particular area – this is intended to limit exposure times and reduce the potential for contamination.145 In addition, soil salvage operations must be carried out in accordance with a schedule included in the approved reclamation plan that seeks to minimize the disturbed area and that is designed to achieve maximum re-vegetation success.146

Require ground preparation, such as scarification and placement of growth media, to prepare for re-vegetation,

[Tags: Re-vegetation; Scarification; Growth Media]

Re-vegetation is generally more effective where the ground has been scarified (left rough and loose), as this promotes seedling establishment and helps retain moisture. A number of jurisdictions legally mandate such ground surface preparation measures. For example:

  • Ontario law requires ground scarification for re-vegetation of disturbed areas – such as flat surfaces compacted by heavy equipment, tailings, building sites, and transportation corridors.147
  • Washington State law requires final reclaimed slopes to be left “roughly graded, preserving equipment tracks, depressions, and small mounds to trap clay-bearing soil and promote natural re-vegetation”.148
  • California State law mandates that where soil has been compacted by mining activities, “ripping, disking, or other means shall be used” to “eliminate compaction and to establish a suitable root zone in preparation for planting”.149

Once the ground surface has been scarified, adequate growth media must be laid down. For effective re-vegetation, this growth media must be of good quality and of sufficient thickness. BC policy requires that growth media on all re-vegetated land “satisfy land use, capability, and water quality objectives.”150 No additional details are outlined under BC law to ensure that this growth media supports long-term re-vegetation and ecosystem restoration. In contrast, laws in other jurisdictions outline more specific requirements to ensure appropriate growth media is used. For example, California law requires soil analyses to be completed to “determine the presence or absence of elements essential for plant growth and to determine those soluble elements that may be toxic to plants, if the soil has been chemically altered or if the growth media consists of other than the native topsoil.”151

In the Yukon, conditions conducive to re-vegetation include “provision of an adequate soil layer with moisture retaining ability, no soil contamination by  hydrocarbons or other hazardous substances, provision of adequate seed or root stock and contoured or otherwise stable slopes.”152

Require testing with trial plots before full-fledged re-vegetation activities are carried out

[Tags: Re-vegetation; Trial Plot Testing]

Site reclamation activities have the greatest likelihood for success where sufficient time is available to run trial tests, learn lessons and adapt methods appropriately.153 The ability to compare actual versus planned occurrences before mine closure can also offer valuable cost and time savings. Therefore, to ensure that re-vegetation activities are effective in the long run, preliminary testing should be conducted with vegetation trial plots. This is recognized in some jurisdictions. For example, California law requires that re-vegetation test plots be conducted simultaneously with mining to determine “the most appropriate planting procedures to be followed to ensure successful implementation of the proposed re-vegetation plan”.154

Commence re-vegetation promptly to reduce soil erosion and loss of soil nutrients

[Tags: Re-vegetation; Dump Slope; Restoration]

Erosion and loss of soil nutrients associated with barren lands can hinder re-vegetation efforts. Successful re-vegetation thus depends on minimizing the length of time that the land lays barren. In BC, no specific legal requirements mandate prompt re-vegetation of barren lands. In contrast, Washington law requires that re-vegetation commence during the first proper growing season after dump slopes have been restored.155 This promotes prompt re-vegetation and minimizes the length of time that the land is barren.

Require re-vegetation with native species

[Tags: Ecology; Traditional Knowledge; Cultural Keystone Species; Re-vegetation]

The types of plants selected to re-vegetate a mine site can significantly impact the success of efforts aimed at re-establishing self-sustaining ecosystems. Priority should be given to native plants species that are generally well suited to local soils and climates. BC law vaguely mandates that land be re-vegetated with “appropriate plant species”; there is no additional legal guidance on what species may be deemed “appropriate”.156 This raises several potential problems, including the possibility that a particular species is selected based on its performance capabilities observed in a different region and climate compared to that in which the mining activity took place.

Laws in other jurisdictions recognize the importance of using local native species for site reclamation. For example:

  • Ontario law requires that the use of native species be considered in determining the appropriate re-vegetation measure for a site.157
  • Yukon law requires that disturbed areas be re-vegetated with “native plant species or other species adaptable to the local environment to encourage re-vegetation comparable to similar, naturally occurring, environments in the area”.158 The law also specified that only non-invasive species be used for re-seeding or transplanting.159US federal law requires “a diverse, effective, and permanent vegetative cover of the same seasonal variety native to the area of land to be affected and capable of self-regeneration and plant succession at least equal in extent of cover to the natural vegetation of the area.”160
  • Colorado law requires that native species be given first consideration.161
  • California law mandates that the vegetative cover or density, and species-richness, be similar to naturally occurring habitats in the surrounding area – the vegetative density, cover and species richness of naturally occurring habitats must be based on that documented in baseline studies carried out prior to the commencement of mining activities.162 California law also mandates that native plant species be used to the maximum extent possible, with introduced species only used where necessary to meet the end uses specified in the approved reclamation plan.163
  • Washington law lists different species for dry versus wet areas in both the eastern and western portions of the state.164

For practical application, First Nations’ traditional knowledge can be a valuable source of information on appropriate local native species for mine site re-vegetation. In addition, native seed collection from undisturbed areas on the mine site can be used to grow seedlings for re-vegetation of disturbed areas.

Require re-vegetation equal to the natural vegetation cover of surrounding areas

[Tags: Re-vegetation; Restoration]

Some jurisdictions have enacted laws that require re-vegetation of disturbed mining areas to at least the state of surrounding un-disturbed lands. For example, South Dakota law requires re-vegetation that is “at least equal in extent of cover to the natural vegetation of the surrounding area”.165 Similar requirements are provided under US federal law.166

Cross-reference mining reforestation activities with forestry laws

[Tags: Reforestation; Restoration]

In BC, forestry practices are extensively dealt with under provincial forestry laws. Where disturbed mining lands are to be re-forested, it is therefore useful and appropriate to incorporate by reference these existing forestry laws. This approach has been adopted in the Philippines where the miner is required to complete reforestation work in disturbed mining areas “in accordance with forestry laws, rules and regulations”.167

Set thresholds to demonstrate effective re-vegetation within set time period

[Tags: Re-vegetation; Scheduling]

Re-vegetation efforts rarely yield immediately results. Rather, re-vegetation it is a process that takes time to become self-sustaining. This reality is partly recognized under BC law by way of the requirement that re-vegetation be completed to a self-sustaining state.168 Other jurisdictions have taken a stronger stance in ensuring environmental protection and regeneration by specifying time periods during which re-vegetation must be shown to be effective. For example:

  • US federal coal mining law requires that successful re-vegetation generally be demonstrated for five years (2 years in areas eligible for mining). In dry areas, successful re-vegetation must be demonstrated for 10 years (5 years in dry areas eligible for further mining).169

 

In California, where irrigation has been used, the miner must demonstrate that re-vegetation has been self-sustaining without irrigation for a minimum of 2 years.170 California law also deems reclamation to be complete only when “productive capability of the affected land is equivalent to or exceeds, for two consecutive crop years, that of the pre-mining condition or similar crop production in the area”.171

Legislate regular inspections of re-vegetation activities

[Tags: Re-vegetation; Inspections]

Under BC law there are no clear and explicit legal requirements to conduct inspections of re-vegetation activities. Thus, inadequate re-vegetation efforts may not be noticed in time to effectively remedy the problematic situations. In contrast, Ontario law requires that re-vegetated areas be inspected on a semi-annually basis, and soil nutrients and pH be evaluated on an annual basis (in spring-time) until vegetation is successfully established.172 Once vegetation has been established, annual inspections must be conducted to identify any necessary repairs, and to review the progress towards the development of a self- sustaining ecosystem.173

Mandate assessment of re-vegetation by other agencies and government departments

[Tags: Assessment; Re-vegetation; Intergovernmental]

As re-vegetation and ecosystem restoration may be beyond the expertise of the mining regulatory authority, support should be obtained from other expert government agencies when assessing the successes of these activities. This is recognized in Oregon where the State Department of Fish and Wildlife and the State Department of Agriculture must certify that a “self-sustaining ecosystem, comparable to undamaged ecosystems in the area” has been established at chemical process mine sites.174

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