IRMA Standard for Responsible Mining (Draft 2.0)
Chapter 3.1 Water Quality

This chapter has been flagged. Your input is welcome on any portion of the Standard. However, we have flagged certain sections where there is either a difference in opinion between stakeholder perspectives and/or a complex topic on which the broader world community is also struggling with no clear resolution. The IRMA Steering Committee would appreciate receiving solutions-based stakeholder input on these issues. Jump to Flagged Section.

 

Background

Mine operations can affect water quality in many ways, including: the discharge of mine water to the environment; seepage through mine wastes to groundwater and surface water; containment breaches; and the release of uncontrolled stormwater. Remediation of mining-caused pollution can be extremely costly, and the design of mine systems to prevent surface water and groundwater contamination should be the goal of the mining operation.

Responsible mining operators can minimize water pollution by using a variety of source control approaches including: limiting infiltration of air and water to acid-bearing/metal leaching waste and mined materials; collecting mine-influenced water as close to the source as possible; and carefully controlling the discharge of stormwater and treated water to the environment.

The proactive identification of potential water quality issues and the development of suitable management strategies adapted throughout the life cycle of a mine can help prevent or minimize surface water and groundwater contamination.

Mining operations can also contribute positively by treating water and making it available for environmental and community uses, and by creating an enhanced understanding for communities and other stakeholders of water-related environmental and community water quality and quantity needs.

Objectives/Intent of this Chapter

To protect water quality and avoid harm to human health, ecosystems and future water uses.

Scope of Application

Chapter Relevance:  This chapter is applicable to all mines applying for IRMA certification.

New vs. Existing Mines: if Approaches A or B are followed, the expectation is that surface water discharges at new mines and existing mines will meet IRMA criteria or water quality will be maintained/improved, respectively. Requirement 3.1.4.2 in Approaches A and B does not apply to existing mines; and 3.1.2.1 does not apply to existing mines unless there is a significant change in mining related activities; and in the case of Approach B, 3.1.1.2 does not apply at existing mines unless practicable, and 3.1.1.3.b does not apply at existing mines unless they are already meeting the requirement.

NOTE TO READERS ON MAJOR CHANGES TO THIS CHAPTER

There is divergence among IRMA Steering Committee sectors regarding this chapter, and input is sought on the three approaches to water quality protection proposed below. In all three approaches, companies would be expected to demonstrate that current and future end-uses of water, and human health and ecosystems are sufficiently protected:

  • Approach A requires a mine to maintain or improve water quality, which is essentially a non-degradation approach (so if there are high quality waters, they are not allowed to be degraded; if there are lower quality waters, a company may not pollute them to a significantly greater extent than they are, and may choose to discharge effluent that actually improves the water quality). This approach is consistent with the US Clean Water Act and US state implementation of non-degradation or anti-degradation laws.
  • Approach B requires a mine to meet a set of water quality criteria (Tables 3.1.a, 3.1.b and 3.1.c) that represent international best practice on a parameter-by-parameter basis. The uses protected include freshwater and salt water aquatic organisms, drinking water, agriculture and irrigation, aquaculture, recreation, and industrial. Meeting these “IRMA water quality criteria” will add a high level of protection for all water quality uses.
  • Approach C requires a company to use risk assessment and management to determine, in consultation with the stakeholders, the water quality priorities for that catchment; to define important current and future uses; and develop water quality goals for mine sites that protect those uses, and to define opportunities to improve water quality on a catchment-wide basis.
  • The inclusion of different options provides companies with flexibility in how they manage and protect water quality, and recognizes that different companies may prefer different approaches. However, there is debate within the IRMA sectors about whether to offer companies a menu of options to choose from, or to specify a preferred approach from which companies may request an exception. Before proceeding any further, IRMA is seeking feedback to ensure that any approach presented in the final Standard can be carried out in a manner that does not endanger water quality, and can be reliably verified by third-party independent auditors. Please see additional information in the flagged section, below.
  • The means of verification (MOV) have been removed from this version of the draft IRMA Standard. If you would prefer to review and comment on a version of the draft Standard that has the means of verification, you can download a pdf version of the Standard with MOV.
     

Water Quality Requirements

3.1.1.  Protection of Water Quality

3.1.1.1.  The operating company shall demonstrate that it protects current human and ecosystem health and future end-uses of water using one of the following approaches:[1]

a. Demonstrate that it is maintaining or improving the baseline water quality of surface or groundwater bodies that receive mine discharges as per Approach A;

b. Demonstrate that mine discharges meet the water quality criteria requirements laid out in Approach B;

c. Demonstrate that it has undertaken a catchment-wide risk-based approach to water quality management that has resulted in the protection of values agreed to by relevant stakeholders as per Approach C.

3.1.1.  Issue in brief:  IRMA is evaluating several approaches for protecting water quality around mine sites. Some industry representatives advocate for a rigorous risk-based approach to defining water quality priorities with stakeholders on a water catchment-wide basis (e.g., watershed/drainage basin), and protecting or improving identified uses (while also meeting any minimum legal water quality requirements); while other IRMA stakeholder sectors would prefer to have a set of standardized criteria that all IRMA mines would meet, so that there is a consistent high bar applied across the board. IRMA is also conscious that rigorous risk assessments that include stakeholder participation may be challenging in some areas or for some companies that may not have the expertise or experience with risk-based assessment processes.

This version of the standard puts forth three possible approaches to water quality protection. We are interested in hearing stakeholders’ opinions on these approaches based on their experiences with water quality protection at mines sites or other similar industries.

The final version of the Standard could include one, two or all three of these options. This decision will be based on stakeholder input, further research and discussions with technical experts. For example, while we have researched water quality requirements in other voluntary certification programs, we will be reaching out to some of these programs to better understand the challenges and successes of approaches already being implemented by certification systems.

Through stakeholder consultation, research and further field testing IRMA will evaluate whether all approaches will meet the objective in 3.1.1, which is to protect current human and ecosystem health and future end-uses of water. We are also seeking input from stakeholders on revisions to existing requirements that will improve the auditability of the various approaches.

Approach A:  Maintain or Improve Water Quality

Note: This is one option to protect current human and ecosystem health and future end-uses of water. The company shall provide auditors with documented rationale for why this approach was taken.

3.1.1.  Protection of Water Quality

3.1.1.1.  Mine effluent discharges shall not significantly change surface water or groundwater quality from baseline water quality. Discharges shall be at concentrations that fall within the 95th percentile of baseline for each parameter.

3.1.1.2.  Mine effluent discharges shall not exceed baseline concentrations for parameters that are carcinogenic.[2]

3.1.2.  Water Quality Modeling

3.1.2.1.  When a new mining project is in the permitting stage, or when significant changes to mining-related activities initiates a new permitting process, the operating company shall utilize an accepted geochemical / hydrological numerical modeling program that:

a. Uses results from geochemical characterization and baseline and operational water quality monitoring to identify which contaminants could be of current and future potential concern;

b. Accounts for temporal changes in both water quality and water quantity during and after mining;

c. Predicts the quality of effluent for pollution-generating facilities on the mine site, and surface water and groundwater quality at the points of compliance during operation, closure, and post-closure;[3]  and incorporates mine water management and movement of contaminants from mine-related sources to receptors.

3.1.2.2.  The assumptions and inputs to the model, and the modeling results, shall be made available for stakeholder review.

3.1.3.  Water Quality Monitoring Program

3.1.3.1.  The operating company shall establish, implement and maintain a documented program to monitor the potential impacts of the mining project on both surface water and groundwater.

3.1.3.2.  The monitoring and modeling program shall be improved by comparing the predicted and actual water quality data and other information that helps define the fate and transport of mine-related contaminants. The model evaluation should occur yearly but, at a minimum, shall be conducted every three years.

3.1.3.3.  The effectiveness of water-quality-related mitigation measures shall be evaluated on an annual basis, using monitoring results. Any necessary changes to mitigation approaches shall be reflected in an adaptive management plan or its equivalent.

3.1.4.  Water Quality Sampling

3.1.4.1.  The water quality monitoring program shall include a water quality sampling plan informed by baseline water quality results, biological and benthic aquatic results, location of mine facilities, groundwater and surface water flow directions, and geochemical characterization of mine waste or other materials which have the potential to adversely impact water quality.

3.1.4.2.  For new mines, baseline water quality for both surface waters and groundwaters shall be established prior to the start of mine construction. Samples shall be collected:

a. In sufficient number to provide statistical reliability to the measurements at each sampling point; and

b. Over a period of at least two years; and

c. In locations where mining-related activities have the potential to influence surface or groundwater.

3.1.4.3.  During operation, closure, and post-closure, sampling shall occur as follows:

a. Sampling points shall be selected to ensure reliable evaluation of the nature and extent of any mine-related contamination;

b. A sufficient number of samples shall be collected to provide statistical reliability to the measurements at each sampling point;

c. Sampling shall take place at a sufficient number of trigger and compliance monitoring points to determine whether baseline water quality for the surface waters and groundwaters affected by the mining project is being maintained or improved;

d. Efforts shall be made to identify when maximum contaminant concentrations exist, and to take samples during those time periods; and

e. Sediment sampling shall be conducted annually at locations where mine facilities (roads, waste rock facilities, etc.) may be contributing sediment to surface waters; and

f. Groundwater monitoring wells for tailings facilities, waste rock dumps, pit lakes, and from underground workings shall be in sufficient quantity and appropriate locations to establish upgradient water quality, and be reasonably able to detect the flow rate and concentration of contaminant plumes, and chemical loading down-gradient from the monitored facility.

3.1.4.4.  Analytical (laboratory) detection limits shall be adequate to confirm that the IRMA water quality criteria can be met.

3.1.5.  Trigger Levels

3.1.5.1.  The operating company shall establish ‘trigger levels’ to provide an early indication that water quality at specified monitoring points is degrading, although it has not yet reached a level at which the applicable water quality criteria are being exceeded.

3.1.5.2.  The operating company shall specify and document in an Adaptive Management Plan or its equivalent the pre-planned responses that will be taken if a trigger level is consistently exceeded, in order to prevent the applicable water quality criteria or objectives from being exceeded.

3.1.6.  Mixing Zones

3.1.6.1.  Mixing zones are not allowed under Approach A.

3.1.7.  Non-Industrial Stormwater

3.1.7.1.  Each significant stormwater discharge point shall be monitored for dissolved metals and important mine-related contaminants, such as nitrate and sulphate, at least once per year, during a storm event.

3.1.7.2.  If the level of dissolved metals and other important mine-related contaminants in the non-industrial stormwater discharge exceeds background water quality (or IRMA water quality criteria if background is not measured), action governed by an adaptive management plan or its equivalent shall be employed to ensure that future stormwater discharges meet relevant water quality criteria.[4]

3.1.8.  Land Application Disposal (LAD)

3.1.8.1.  Land application disposal is not allowed under Approach A.

3.1.9.  Publication of Water Monitoring Results

3.1.9.1.  Water quality data for surface water and groundwater points of compliance, and the trigger-level measuring points, shall be published in electronic format quarterly on the mine or company web site.

3.1.9.2.  Graphical presentation of water quality data for surface water and groundwater points of compliance, and the trigger-level measuring points, shall be published annually on the mine or company website.

Approach B:  Meet IRMA Water Quality Criteria

Note: This is one option to protect current human and ecosystem health and future end-uses of water. The company shall provide auditors with documented rationale for why this approach was taken.

3.1.1. Protection of Water Quality

3.1.1.1.  The operating company shall demonstrate that water discharges to surface waters and groundwaters with the exception of non-industrial stormwater and discharges to protected waters or high quality waters, comply at the point of compliance with the IRMA water quality criteria in Tables 3.1.a, 3.1.b or 3.1.c. (See tables at the end of the chapter)

a. An exception shall be made if the natural background concentration of a particular parameter is higher than an IRMA water quality criterion, in which case, the applicable baseline water quality concentration of that parameter shall be maintained.

3.1.1.2.  Protected waters and/or high-quality waters shall not be degraded above baseline water quality by mine discharges.[5]

3.1.1.3.  The water quality criteria for surface water and groundwater shall be met:

a. At the point of discharge for surface waters, or, where a mixing zone is allowed, at the edge of the mixing zone;

b. At the point(s) of compliance for groundwaters, which shall be located inside of, but no further than the mine boundary, unless a groundwater mixing zone has been allowed;[6] 

c. If mine-influenced groundwater is discharging into a surface water via a spring, seep, or in a stream bed (hyporheic zone), then the groundwater discharge shall be treated as a surface water mine discharge for water quality purposes; and

d.  If the groundwater discharge is into a hyporheic zone where spawning is present, the groundwater discharge shall meet surface water standards in the hyporheic zone.

3.1.2.  Water Quality Modeling

3.1.2.1.  When a new mining project is in the permitting stage, or when significant changes to mining-related activities initiates a new permitting process, the operating company shall utilize an accepted geochemical / hydrological numerical modeling program that:

a. Uses results from geochemical characterization and baseline and operational water quality monitoring to identify which contaminants could be of current and future potential concern;

b. Accounts for temporal changes in both water quality and water quantity during and after mining;

c. Predicts the quality of effluent for pollution-generating facilities on the mine site, and surface and groundwater quality at the points of compliance during operation, closure, and post-closure;[7]  and incorporates mine water management and movement of contaminants from mine-related sources to receptors.

3.1.2.2.  The assumptions and inputs to the model, and the modeling results, shall be made available for stakeholder review.

3.1.3.  Water Quality Monitoring Program

3.1.3.1.  The operating company shall establish, implement and maintain a documented program to monitor the potential impacts of the mining project on both surface water and groundwater.

3.1.3.2.  The monitoring and modeling program shall be improved by comparing the predicted and actual water quality data and other information that helps define the fate and transport of mine-related contaminants. The model evaluation should occur yearly but, at a minimum, shall be conducted every three years.

3.1.3.3.  The effectiveness of water-quality-related mitigation measures shall be evaluated on an annual basis, using monitoring results. Any necessary changes to mitigation approaches shall be reflected in an adaptive management plan or its equivalent.

3.1.4.  Water Quality Sampling

3.1.4.1.  The water quality monitoring program shall include a water quality sampling plan informed by baseline water quality results, biological and benthic aquatic results, location of mine facilities, groundwater and surface water flow directions, and geochemical characterization of mine waste or other materials which have the potential to adversely impact water quality.

3.1.4.2.  For new mines, baseline water quality for both surface waters and groundwaters shall be established prior to the start of mine construction. Samples shall be collected:

a. In sufficient number to provide statistical reliability to the measurements at each sampling point; and

b. Over a period of at least two years; and

c. In locations where mining-related activities have the potential to influence surface water or groundwater.

3.1.4.3.  During operation, closure, and post-closure, sampling shall occur as follows:

a. Sampling points shall be selected to ensure reliable evaluation of the nature and extent of any mine-related contamination;

b. A sufficient number of samples shall be collected to provide statistical reliability to the measurements at each sampling point;

c. Sampling shall take place at a sufficient number of trigger and compliance monitoring points to determine whether the IRMA water quality criteria for the surface and groundwaters affected by the mining project are being met;

d. Efforts shall be made to identify when maximum contaminant concentrations exist, and to take samples during those time periods;

e. Sediment and macroinvertebrate sampling shall be conducted annually at surface water locations key to verifying that there are no toxic impacts due to mine discharges outside designated mixing zones; and

f. Groundwater monitoring wells for tailings facilities, waste rock dumps, pit lakes, and from underground workings shall be in sufficient quantity and appropriate locations to establish upgradient water quality, and be reasonably able to detect the flow rate and concentration of contaminant plumes, and chemical loading down-gradient from the monitored facility.

3.1.4.4.  Analytical (laboratory) detection limits shall be adequate to confirm that the IRMA water quality criteria are being met.

3.1.5.  Trigger Levels

3.1.5.1.  The operating company shall establish ‘trigger levels’ to provide an early indication that water quality at specified monitoring points is degrading, although it has not yet reached a level at which the applicable water quality criteria are being exceeded.

3.1.5.2.  The operating company shall specify and document in an adaptive management plan or its equivalent the pre-planned responses that will be taken if a trigger level is consistently exceeded, in order to prevent the applicable water quality criteria from being exceeded.

3.1.6.  Mixing Zones

3.1.6.1.  A surface or groundwater mixing zone shall only be allowed if:

a. It was subject to a comprehensive, documented risk assessment prior to implementation, including evaluations of the risks to human health, potential economic impacts, effects on aquatic biota, and changes to sediment quality;

b. It is as small as practicable;

c. It does not contain a zone of acute toxicity to any resident or transient aquatic species;

d. It does not interfere with the passage of migratory fish;

e. It does not include the water intake or cone of depression associated with a well for any pre-mine public or private drinking water source;

f. It does not interfere with a pre-mine use of water for irrigation or livestock, unless that use can be adequately provided by a similar or better quality and volume by the mining operation through another source, and that this substitution is agreed to by all relevant water users; and

g. It was subject to a credible, transparent process of stakeholder review and consultation prior to implementation.

3.1.6.2.  The discharge of effluent into a surface water mixing zone shall take place only after the application of best practice water treatment technologies.

3.1.6.3.  If fish are present, whole effluent toxicity testing and benthic community testing shall be conducted at least annually on the effluent entering the mixing zone to evaluate the toxicity of the treated effluent.

3.1.6.4.  Discharges of effluent into the mixing zone shall match the local hydrograph in relation to surface water flows to the extent practicable.

3.1.7.  Non-Industrial Stormwater

3.1.7.1.  Each significant stormwater discharge point shall be monitored for dissolved metals and important mine-related contaminants, such as nitrate and sulphate, at least once per year, during a storm event.

3.1.7.2.  If the level of dissolved metals and other important mine-related contaminants in the non-industrial stormwater discharge exceeds IRMA water quality criteria, action governed by an adaptive management plan or its equivalent shall be employed to ensure that future stormwater discharges meet IRMA water quality criteria (measured as dissolved metals). Non-industrial stormwater is not required to meet the suspended solids criteria.[8]

3.1.8.  Land Application Disposal (LAD)

3.1.8.1.  Land application disposal areas shall be designed so that breakthrough of contamination will not occur.

3.1.8.2.  LAD shall not be a primary treatment method for metals.[9]

3.1.8.3.  Prior to land application there shall be a rigorous analysis that shall show:

a. The absorption capacity of the soils in the LAD;

b. Which contaminant will saturate the soils first;

c. That monitoring, including trigger levels, for both surface and groundwater contamination in the LAD area has been implemented; and

d. That the level of contaminants taken up in plants will pose no danger of contaminant accumulation that poses a risk to human health, wildlife, or domestic animals.

3.1.8.4.  If any contaminant value exceeds the surface or groundwater values predicted by the analysis of 3.1.8.3, use of the LAD area shall be discontinued until contaminant values no longer exceed predicted levels.

3.1.9.  Publication of Water Monitoring Results

3.1.9.1.  Water quality data for surface and groundwater points of compliance, and the trigger-level measuring points, shall be published in electronic format quarterly on the mine or company website.

3.1.9.2.  Graphical presentation of water quality data for surface and groundwater points of compliance, and the trigger-level measuring points, shall be published annually on the mine or company website.

Approach C:  Implement Catchment-Wide, Risk-Based Water Quality Management

Note: This is one option to protect current human and ecosystem health and future end-uses of water. The company shall provide auditors with documented rationale for why this approach was taken.

3.1.1.  Protection of Water Quality

3.1.1.1.  The operating company shall apply a risk framework to evaluate and manage water quality consistent with the international standard Risk Management – Principles and Guidelines (ISO31000:2009).

3.1.1.2.  The operating company shall demonstrate a commitment to a catchment-wide risk-based approach to understanding and addressing water needs and managing water quality in a manner that protects current human and ecosystem health and future end-uses of water.

3.1.2.  Understand the Catchment Context

3.1.2.1.  The operating company shall consult with communities, regulators, and other relevant stakeholders to understand the catchment context, including past, current, and potential future human, environmental, cultural, agricultural, and industrial uses and to understand stakeholder needs and concerns regarding water quality.

3.1.2.2.  As part of this process, the operating company shall:

a. Obtain, distribute, review and summarize relevant environmental data on the hydrology, land use, water use and water quality in catchments within the vicinity of the mining operation;

b. Obtain, distribute, review and summarize relevant environmental data to understand baseline and background conditions, including waters affected by natural mineralization and pollution from sources not related to operations at the mine site;

c. Obtain and distribute to stakeholders relevant information about existing water quality objectives established by regulators for the catchment; and

d. Ensure that stakeholders have the capacity to be meaningfully informed and engaged about water issues at the catchment level.

3.1.3.  Develop Mine Site Context

3.1.3.1.  For new projects, a sufficient number of statistically reliable samples covering a period of at least two years shall be collected prior to the start of mine construction to establish baseline water quality for both surface waters and groundwaters.

3.1.3.2.  The operating company shall establish, implement and maintain a documented program to understand and monitor potential impacts of the mining operation on both surface and groundwater, appropriate to the scope and scale of the operation. (See also criteria 3.1.9)

3.1.3.3.  A new project shall undertake geochemical / hydrogeological evaluations and a modeling effort appropriate to the nature and scale of the planned operation and the surrounding land and water uses, for incorporation into the environmental impact assessment, the risk assessment(s) described in Section 3.1.5.1, and permitting or licencing process to:

a. Use results from geochemical characterization and baseline and operational water quality monitoring to identify which contaminants could be of current and future potential concern;

b. Account for temporal changes in both water quality and water quantity during and after mining;

c. Predict potential surface and groundwater quality for pollution-generating facilities on the mine site, and at the points of compliance during operation, closure, and post-closure;

d. Incorporate mine water management and movement of mine-related contaminants from mine facilities from sources to receptors; and

e. Predict whether surface and/or groundwater quality will be an issue post-closure.

3.1.3.4.  Operational monitoring results shall be used to calibrate or improve the model. Evaluation of the model shall occur at a defined period appropriate to the monitoring program.

3.1.4.  Develop Water Quality Goals

3.1.4.1.  The operating company shall utilize information and data gathered in 3.1.2 to confirm water uses downstream of the mining operation (e.g., aquatic biodiversity, agriculture, human uses, industry).

3.1.4.2.  The operating company shall refer to regulatory requirements and establish water quality objectives and numeric water quality goals that protect identified current and future uses within the catchment. Tables 3.1.d to 3.1.j shall provide a guide in establishing numeric water quality goals. (See tables at the end of the chapter.)

3.1.4.3.  Water quality goals and trigger levels shall be established to ensure that protected waters and high quality waters are given the highest priority for protection to ensure they are not degraded.

3.1.5.  Application of a Risk Framework:  Risk Assessment and Management

3.1.5.1.  The operating company shall carry out a water quality risk assessment that incorporates the following:

a. The risk context shall be established using information gathered in 3.1.2 to 3.1.4, including mine site-specific contextual data.

b. Risks shall be identified and analysed by systematic review of data and information gathered through stakeholder engagement, and shall consider risks, threats, consequences, barriers to prevent threats from occurring, and controls to mitigate the consequence of risks.

c. The probability and consequence of all potential water quality impacts shall be assessed for each mine facility (e.g., waste rock, tailings impoundment, open pit, underground, and stormwater run-off from industrial and non-industrial areas), and shall identify leading practices to prevent or minimize water quality impacts.

d. Stakeholders shall be given the opportunity to provide input into the risk assessment process, and improvements will be reviewed for incorporation in response to stakeholder input.

e. The risk assessment shall be revised at least annually or when there have been significant incidents or significant changes to mining-related activities.

3.1.5.2.  The operating company shall manage water quality risks as follows:

a. A risk management approach shall be utilized that is based on a waste minimization and water conservation hierarchy that prioritizes in the order of avoidance of impact, reduction of use, reuse, recycling, treatment, containment, and lastly, disposal.

b. Risk management strategies shall be designed to protect the water quality goals established in 3.1.4.

c. A risk management plan or its equivalent (e.g., water management plan or adaptive management plan) shall be created based on the results of the risk assessment. The plan shall identify actions to be taken and responsibilities for the actions and communications with stakeholders in the event of an identified water quality issue; and shall be used to evaluate the effectiveness of the mine management, mitigation, monitoring, and modeling programs.

d. The risk management plan shall be updated annually, or as needed, to incorporate input from ongoing consultations and monitoring results, and to include new information as it becomes available.

3.1.6.  Waste Management and Mitigation

3.1.6.1.  Where the risk management plan or its equivalent requires the prevention and mitigation of water quality impacts, the operating company shall review and implement best available techniques to mitigate identified risks.[10]

3.1.7.  Mixing Zones

3.1.7.1.  Where surface water or groundwater mixing zones are to be utilized as a risk management option, the evaluation shall be subject to a comprehensive, documented risk assessment prior to implementation, including evaluations of the risks to human health, potential economic impacts, effects on aquatic biota, and changes to sediment quality.

3.1.7.2.  The mixing zone shall:

a. Be as small as practicable;

b. Not contain a zone of acute toxicity that would significantly affect fish and other aquatic animals;

c. Not interfere with the passage of migratory fish; and

d. Not include impacts that affect water uses of the water intake or cone of depression associated with a well for any pre-mine public or private drinking water source; nor interfere with a pre-mine use of water for irrigation or livestock, unless that use can be adequately provided by a similar or better quality and volume by the mining operation through another source, and that this substitution is agreed to by relevant water users.

3.1.7.3.  Where the mixing zone may extend beyond the boundary of the mine site, the mixing zone evaluation shall be subject to a credible, transparent process of community review and consultation (per section 2.8.2. of the IRMA Standard) prior to implementation.

3.1.7.4.  The discharge of effluent into a surface water mixing zone shall take place only after both the application of leading practice water treatment technologies and a plan to manage the mixing zone to achieve the goals of 3.1.7.2 are in place.

3.1.8.  Land Application Disposal (LAD)

3.1.8.1.  Where LAD areas are to be utilized as a risk treatment option, the following shall apply:

a. They shall be designed so that breakthrough of contamination will not occur.

b. LAD shall not be a primary treatment method for metals.

3.1.8.2.  Prior to land application there shall be a rigorous analysis to show:

a. The absorption capacity of the soils in the LAD;

b. Which contaminant will saturate the soils first;

c. That monitoring, including trigger levels, for both surface water and groundwater contamination in the LAD area has been implemented; and

d. That the level of contaminants taken up in plants will pose no danger of contaminant accumulation to human health, wildlife, or domestic animals.

3.1.8.3.  If a contaminant trigger level is exceeded at a LAD surface water or groundwater trigger monitoring point use of the LAD area shall be discontinued until all contaminant levels drop below the trigger levels, and the risk assessment shall be reviewed.

3.1.9.  Monitoring Program

3.1.9.1.  The risk management plan shall include a water quality monitoring program with the results used in the review of water quality goals and risk assessments and plans at an appropriate frequency (in accordance with 3.1.5.2.d).

3.1.9.2.  The monitoring program shall include a water quality sampling plan informed by baseline water quality (for new mines) or background water quality (for existing mines), water quality results, biological and benthic aquatic results, location of existing and proposed mine facilities, groundwater and surface water flow directions, and geochemical characterization of mine waste or other materials which have the potential to adversely impact water quality.

a. The program shall include a sufficient number of sampling points to determine which water quality goals established in 3.1.4 should be applied for the surface and groundwaters affected by the mining project, and whether these criteria as established are being met;

b. Sampling points shall be selected to ensure reliable evaluation of the nature and extent of any mine-related contamination;

c. Water quality, sediment and macroinvertebrate sampling shall be conducted annually or as relevant to assess impacts at surface water locations against water quality goals and verify that there are not toxic impacts to aquatic ecosystems due to mine discharges;

d. Trigger levels and trigger monitoring locations shall be established to provide an early warning system for water quality effects;

e. Analytical detection limits shall be adequate to confirm whether the relevant trigger levels and water quality criteria are being met at respective trigger and compliance points; and

f. During operation, closure, and post-closure, a sufficient number of samples shall be collected to provide statistical reliability to the measurements at each sampling point.

3.1.9.3.  Efforts shall be made to identify when maximum contaminant concentrations exist, and to take samples during those time periods.

3.1.10.  Publication of Water Monitoring Results

3.1.10.1.  Water quality data for surface water and groundwater monitoring locations shall be published in a format that is accessible and useful for stakeholders and at a frequency that meets the needs of stakeholders (at least annually, and quarterly if monitoring data are available).

3.1.10.2.  Feedback about the accessibility, usefulness, and frequency of data availability shall be sought from stakeholders and considered in planning future communications.

3.1.11.  Compliance with Water Quality Goals

3.1.11.1.  The operating company shall demonstrate that water discharges to surface waters and groundwaters comply at the discharge point of compliance with the water quality goals established in 3.1.4.

3.1.11.2.  The water quality goals for surface water and groundwater shall be met:

a. At defined points of compliance for surface waters, which, for a mixing zone, will be at the downstream end of the mixing zone; and

b. At groundwater compliance sites located outside the groundwater capture zone. If groundwater is discharging via a spring, seep, or through a stream bed (hyporheic zone) into a surface water reach where spawning is present, the groundwater discharge will be required to meet surface water quality goals.

3.1.11.3.  Where trigger levels are exceeded at trigger monitoring locations, corrective actions shall be taken.

3.1.12.  Environmental and Community Water Uses

3.1.12.1.  Where appropriate as part of an overall risk management strategy, mining operations may consider ways to contribute positively to environmental and community uses such as by treating water and making it available for other uses. Such opportunities would be considered in consultation with relevant local community and government stakeholders.

Water Quality Tables

IRMA Water Quality Criteria (protective of most sensitive uses)
3.1.a—IRMA Surface Fresh Water Quality Criteria
3.1.b— IRMA Fresh Groundwater Quality Criteria
3.1.c— IRMA Salt Water Quality Criteria

Criteria by Designated Use
3.1.d—Aquatic Organisms ‐ Fresh Water Quality Criteria
3.1.e—Aquatic Organisms ‐ Salt Water Quality Criteria
3.1.f—Human Health Drinking Water Quality Criteria

3.1.g—Agriculture ‐ Irrigation Water Quality Criteria
3.1.h—Aquaculture Water Quality Criteria
3.1.i—Recreational Water Quality Criteria
3.1.j—Industrial Water Quality Criteria

Note:  Data and rationale for IRMA and designated use criteria values are available upon request.

Abbreviations  
Bq/L = Becquerel per Liter
s.u. = standard units
CaCO3 = calcium carbonate
Tot. = Total
degC = degrees centigrade
µg/L = micrograms per Liter
mg/L = milligrams per Liter
WAD = weak acid dissociable

Notes

IRMA Water Quality Criteria

For Approach B, the IRMA surface water and groundwater quality criteria were chosen to protect all potential beneficial uses – aquatic organisms (surface waters), drinking water, human health, and irrigation, agriculture and livestock.  While this may be a rigorous requirement, it is best practice. IRMA is cognizant that these criteria, taken as a whole, will be more stringent than the criteria in most existing regulatory permits for existing and future mines.  Provisions are made for baseline water quality conditions that exceed the IRMA criteria.

The IRMA water quality criteria were chosen from a mix of international water quality criteria, which are listed in the Notes of Table 3.1.b. Sometimes the criteria from different sources matched, in which case that number was used.  If they differed slightly then the most prominently cited number was chosen.  In most cases where only one entity had a criterion for a particular parameter, that contaminant was not listed. There were exceptions to these guidelines.  A detailed list comparing the criteria from each international source is available, along with an explanation of how a particular IRMA criterion was chosen among the various international criteria.  This detailed comparison exists on an Excel spreadsheet that is available on request.

Stormwater

In Approaches A and B, the intent of criteria 3.1.7 is to identify whether there are significant problems with non-industrial stormwater runoff from the mine facility, and to rectify these problems using existing Best Management Practices (BMPs). Criteria 3.1.7 contains a requirement to measure non-industrial stormwater discharges once a year during a storm event (this is a best practice).  It is assumed that all sample collecting will be conducted in a manner that does not jeopardize the safety of the sample collector.

Most non-industrial stormwater is routed through a settling pond, although that is not a requirement.  Whether it is or not, non-industrial stormwater should meet either IRMA numerical water quality criteria or baseline water quality, since it is technically un-impacted water.  If it does not, then something on the mine site is impacting that stormwater, so some form of additional treatment is required. Additional treatment could be as simple as increasing the residence time or adding flocculent in a settling pond, or employing better BMPs, including increased settling time, the addition of flocculants, or other treatment technologies.

Since most impacts of metals to organisms are related to dissolved quantities of metals, and since the suspended solids in non-industrial stormwater are often high and can yield correspondingly high “total” metals levels, IRMA is recommending using “dissolved” metals to judge compliance with the IRMA criteria.  It is the intent that stormwater meet the IRMA criteria for suspended solids through settling or other means, but it is not an absolute requirement for storm related discharges because of high storm flow volumes.

Cross Reference to Other Chapters

 Chapter

 Issues

1.1—Legal Compliance As per Chapter 1.1, if there are host country laws that pertain specifically to the topics addressed in any IRMA chapter (e.g., the use of mixing zones in Approach B, 3.1.6 and Approach C, 3.1.8), the company is required to abide by those laws. If IRMA requirements are more stringent than host country law, the company is required to also meet the IRMA requirement, as long as complying with it would not require the operating company to break the host country law.

So, for example, if host country law related to water quality criteria are more protective of human health or the environment than IRMA requirements, the host country requirements supersede IRMA requirements. But if IRMA requirements are more stringent than host country law, the company will meet the IRMA requirements, as long as complying with them would not require the company to break host country law.
2.8—Community and Stakeholder Engagement The requirement to consult with stakeholders regarding mixing zones (in Approach B, 3.1.6) shall conform with IRMA stakeholder engagement requirements in Chapter 2.8. This includes determining if the stakeholders have the capacity to effectively participate in discussions, and provision for access to independent experts if necessary to ensure meaningful engagement.

Similarly, in the risk-based approach option to water quality protection (Approach C), the various requirements related to stakeholder engagement will need to meet the requirements in Chapter 2.8, including, the provision of capacity building or access to independent experts if that is what is needed for effective participation in the risk-based approach processes.
3.2—Water Quantity Chapter 3.1 addresses issues relating to water quality. Chapter 3.2 considers issues relating to the quantity of water used.
3.3—Mine Waste Management Requirements in Chapter 3.3 address pit and underground backfill, liners, and lake-riverine-ocean waste disposal.
4.2—Reclamation and Closure Requirements in Chapter 4.2 address financial sureties and long-term/perpetual water treatment.

 

Endnotes

1. The operating company shall provide auditors with documented rationale for why a particular approach was taken.

2. "Carcinogen" means any substance or agent that produces or tends to produce cancer in humans. For the purposes of this chapter, the term carcinogen will apply to substances listed by the International Agency for Research on Cancer (IARC) that are classified as Group 1 (carcinogenic to humans) or Group 2A (probably carcinogenic to humans). In relation to mining, carcinogens of concerns may include, but are not limited to: arsenic, cadmium, beryllium, chromium (VI), lead, nickel, and some radioactive compounds. View the IARC list of classifications.

3. i.e., predicts whether surface water and/or groundwater quality will be an issue post-closure.

4. Non-industrial stormwater would not need to meet the IRMA suspended solids criteria. See Notes at the end of the chapter for additional discussion.

5. This applies at new mines, and at existing mines where practicable.

6. This applies at new mines and at mines that are presently meeting this requirement.

7.  i.e., predicts whether surface and/or groundwater quality will be an issue post-closure.

8. See Notes at the end of the chapter for additional discussion.

9. Use of LAD for polishing is acceptable.

10. Techniques may include: limiting water and oxygen ingress to acid bearing materials such as through surface and groundwater diversion of water to avoid infiltration of mine-related constituents, soil compaction of mining wastes to minimize ingress of oxygen and water, selective placement of acid bearing materials in-pit or underground, careful management of water use in mining and beneficiation, design of wet or dry covers for waste rock, clay seals, and responsible placement and management of tailings. Where risk mitigation is to be considered, options would be considered such as addition of chemicals to generate alkalinity or to neutralize acidity, and water treatment such as reverse osmosis, ion exchange, or passive treatment to reduce acidity.

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