Gi Giant M Mine R Remediation on Proj oject t Water Licence - - PowerPoint PPT Presentation

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Water Licence Intervention – Slater Environmental Consulting

Role o

• f S

f Slater Environmental C Consulti ting

Independent Advisor to Giant Mine Working Group (GMWG)

• Terms of Reference: “…provide

independent technical expertise and advice … to the GMWG…”

• Principles:
• Independence
• Collaboration
• Transparency
• May 2014

Role in Water Licence Process

• “Jointly engaged expert”
• Role options discussed by GMWG in

early 2019

• City of Yellowknife letter to Board,

May 2019

• “…provide evidence and have

that evidence examined…”

• Independent: not presenting

position of the GMWG, or any party on the GMWG

December 12, 2019 Slater Environmental Consulting - Advisor to Giant Mine Working Group 2

Presenta ntation C Cont ntext

• Review comments provided on May 25, 2019: “Review of Post-EA

Information Package Giant Mine Remediation Project”

• Addressing topics raised by GMWG representatives
• Participation in July 2019 Technical Session
• Review of additional information
• Review of discussions at September 2019 Workshop and Technical

Session

• Written intervention November 14, 2019: “Licensing

Recommendations – Giant Mine Remediation Project”

• Review of December 2, 2019 Response to Interventions

December 12, 2019 Slater Environmental Consulting - Advisor to Giant Mine Working Group 3

Recomme mmendation 1: Future Land Use Constraints

• Not practical to remediate soils across the site to the

Yellowknife industrial remediation standard of 340 mg/kg of arsenic

• Soils with elevated arsenic concentrations are

widespread across the site and beyond

• Soils with concentrations as high as at least 3000 mg/kg

will be left in place – a permanent exposure source for humans and the environment

• Permanent administrative control of future land use

activities

• Long-term legacy for future generations – challenges for

long-term management of human activities

December 12, 2019 Slater Environmental Consulting - Advisor to Giant Mine Working Group 4

Recomme mmendation 1: Future Land Use Constraints

• Human Health Risk Assessment:
• Risks are low if human use is limited
• Moving through the area – e.g., walking, cycling, running
• Casual use for short periods of time

December 12, 2019 Slater Environmental Consulting - Advisor to Giant Mine Working Group 5

Recomme mmendation 1: Future Land Use Constraints

Objectives

• Understanding versus Action
• “Residual risks are identified, and local

residents have been, and continue to be, informed of residual hazards” Versus

• Residual risks are identified and local

residents use this information to make and implement land use decisions that avoid unacceptable risks

Criteria

• Communication versus Constraints/Action
• Purpose of communication is to create

appropriate day-to-day action – e.g., not camping in areas with high arsenic concentrations

• Criterion should focus on the desired land use
• utcome – that is what we need to measure
• Land use constraints are also needed
• What are the rules and how do we make sure

they are permanent?

• E.g., no residential development in certain areas
• Criterion should focus on whether we have

appropriate constraints in place

December 12, 2019 Slater Environmental Consulting - Advisor to Giant Mine Working Group 6

Recomme mmendation 1: Future Land Use Constraints

• Recommendation:
• Board should require the co-proponents to establish definitive

administrative constraints on future land use in parts of the project area that have soil arsenic concentrations that exceed residential standards but do not include physical barriers

• Board should require progress reporting on the establishment of

these constraints and monitoring of their effectiveness

• Not about what future land use will be – rather what it

CANNOT be.

• Will require the co-proponents to use broader government

authority

• Perpetual Care Plan
• Areas both inside and outside the lease boundary

December 12, 2019 Slater Environmental Consulting - Advisor to Giant Mine Working Group 7

Recomme mmendation 2: Potenti tial Ecological Risks

• Ecological Risk Assessment:
• “…there is the potential for the

smaller animals at the site to be affected by arsenic and antimony.”

• Future Monitoring:
• Biological studies to examine the

health of vegetation at the site

• Collection of insect data to verify

assessment assumptions

• Examination of any differences in

abundance and diversity of vegetation and mammals

• Other post-remediation monitoring
• Response to interventions:
• HHERA had sufficient data to draw

conclusions

• No significant uncertainties
• Wildlife and Wildlife Habitat

MMP

• No components aimed at

addressing the recommendations from the risk assessment.

December 12, 2019 Slater Environmental Consulting - Advisor to Giant Mine Working Group 8

Recomme mmendation 3: Proactive Ad Adaptive M Management

• Adaptive management in the context of a mining project:
• Consistent and transparent framework for responding to deviations in

project performance or unforeseen environmental (social, cultural?) conditions

• Pre-planned framework for making quick and efficient decisions
• Current GMRP proposal:
• Contingency measures in management plans: e.g., Tailings Monitoring and

Management Plan – Contingency action if water quality exceeds discharge criteria

• Response plans in aquatic environment: e.g., in Yellowknife Bay

December 12, 2019 Slater Environmental Consulting - Advisor to Giant Mine Working Group 9

Recomme mmendation 3: Proactive Ad Adaptive M Management

• Identify project aspects with uncertainty that could lead to changing
• r unexpected performance
• Proactive monitoring to detect changing conditions at locations and

within timeframes that allow for effective response.

• Clear and defensible triggers that will ensure timely implementation
• f effective responses.
• Clear and transparent process for developing appropriate

management responses in response to triggers being reached or exceeded.

December 12, 2019 Slater Environmental Consulting - Advisor to Giant Mine Working Group 10

Recomme mmendation 3: Proactive Ad Adaptive M Management

• What should we monitor

and where should we monitor if we want to detect and respond to changes quickly?

• How do we know when

we need to respond?

• What responses can we

make?

• What processes will help

us figure out what to do?

December 12, 2019 Slater Environmental Consulting - Advisor to Giant Mine Working Group 11

Recomme mmendation 3: Proactive Ad Adaptive M Management

• Comprehensive Adaptive

Management Plan for Phases 1 and 2

• Key areas of performance

uncertainty, e.g.:

• Covers
• Loading from pit runoff
• Conditions in remediated Baker

Creek

• Runoff and seepage from

remediated areas

• Adaptive management

components

• Indicators
• Monitoring
• Thresholds/action levels
• Analysis/interpretation methods

and timing

• Responses
• Reporting
• Part of environmental

management

December 12, 2019 Slater Environmental Consulting - Advisor to Giant Mine Working Group 12

Recomme mmendation 4: Long-term rm Ad Administration a and F Funding

Phase 2 – Closure Implementation

• Government project
• Government proponents
• Main Construction Manager
• Government appropriations

Phase 3 – Post-closure

• Will the same mechanisms work?
• Report of Environmental

Assessment – Measure 6

• Challenges re: funding for very long-

term projects

• Investigation of long-term funding
• ptions – post-closure maintenance

and contingencies

• Consider trust fund with multi-year

up front funding

December 12, 2019 Slater Environmental Consulting - Advisor to Giant Mine Working Group 13

Recomme mmendation 4: Long-term rm Ad Administration a and F Funding

• Permanent requirements:
• Maintenance of water management

structures

• Pumping and water treatment
• Maintenance of freezing system
• Administrative delivery

mechanisms and funding mechanisms are linked

• Additional work is needed to figure
• ut what combination of delivery

and funding mechanisms makes sense for the post-closure GMRP

December 12, 2019 Slater Environmental Consulting - Advisor to Giant Mine Working Group 14

Recomme mmendation 4: Long-term rm Ad Administration a and F Funding

• Recommendations:
• Limit licence term to Phase 2
• Require additional work to evaluate and select effective long-term

administration and funding mechanisms

• Engage public and affected parties

December 12, 2019 Slater Environmental Consulting - Advisor to Giant Mine Working Group 15

Recomme mmendation 5: Pi Pit Backfilling and Covers

• Recommendation: Board should require

further analysis and design related to pit remediation, including about materials for pit filling and the need for pit covers.

• Additional information about materials has

been shared, and further work is proposed

• Need for pit covers remains uncertain and

warrants further discussion

December 12, 2019 Slater Environmental Consulting - Advisor to Giant Mine Working Group 16

Recomme mmendation 6: Land Reclamation and R Re-ve vegetation

• Recommendation: Require the development of appropriate closure
• bjectives and criteria that define expectations for land reclamation

and future conditions of the terrestrial environment

• GMRP:
• Reclamation in areas where it is required to prevent erosion
• Re-vegetation efforts will be minimal
• Uncertainty and confusion about basis for decision-making about

land reclamation and expectations for future conditions of the terrestrial environment

December 12, 2019 Slater Environmental Consulting - Advisor to Giant Mine Working Group 17

Recomme mmendation 6: Land Reclamation and R Re-ve vegetation

• Define expected outcomes for:
• Re-vegetation
• Surface disturbance
• Wildlife habitat
• Land use capacity, etc.
• Balance
• Use post-closure terrestrial

conditions to inform people about risks

• Conduct effective reclamation

where risks are negligible

December 12, 2019 Slater Environmental Consulting - Advisor to Giant Mine Working Group 18

Recomme mmendation 7: Tes estin ing of

• f Water

er T Trea eatment Resid esiduals

• Recommendation:

Require further testing

• f water treatment

residuals for the new water treatment plant

• Testing of sludge to-date has relied on

sludge samples from the existing effluent treatment plant

• Similar treatment processes, but storage

conditions are not the same

• Current sludge is stored under water
• Future sludge will be stored in landfill cell
• Need to confirm:
• Characteristics of sludge from new plant
• Sludge stability in new storage conditions

December 12, 2019 Slater Environmental Consulting - Advisor to Giant Mine Working Group 19

Recomme mmendation 8: Management and Monitori ring Pl Plans

• Ensure that plans approved with this application address the needs

for Phase 1 of the project – current operations

• E.g., Erosion and Sediment Management and Monitoring Plan

contains very little detail, with details to be submitted as part of Design and Construction Plans.

• Where are details for current operations?

December 12, 2019 Slater Environmental Consulting - Advisor to Giant Mine Working Group 20

Recomme mmendation 9: Scope pe of Aqua uatic Effects Moni nitoring P Plans

• Recommendation: Aquatic effects

monitoring plans should be in place for both Baker Creek and Yellowknife Bay for all phases of the project

December 12, 2019 Slater Environmental Consulting - Advisor to Giant Mine Working Group 21

Recomme mmendation 10: Effluent Q Quality C Criteri ria

• Recommendation: Establish

effluent quality criteria for sulphate and chloride

• GMRP response – can accept

criteria for sulphate and chloride

December 12, 2019 Slater Environmental Consulting - Advisor to Giant Mine Working Group 22

Recomme mmendation 11: Ne Nearshore e Sedimen ents in Yellowknife e Bay

• Recommendations:
• Refinement of closure criteria for

remediation of nearshore sediments

• Robust monitoring program for

proposed covers

• GMRP response – refinement of

closure criteria is planned

December 12, 2019 Slater Environmental Consulting - Advisor to Giant Mine Working Group 23 Photo: SRK Consulting

Qu Ques estion

• ns?

December 12, 2019 Slater Environmental Consulting - Advisor to Giant Mine Working Group 24