MV2011L2-0004 SNAP LAKE WATER LICENCE AMENDMENT TECHNICAL SESSIONS 22.Jan.2015 The De Beers Group of Companies
Overview of Water Licence Amendment Applications - TDS Section Title De Beers is applying to change the quality of water allowed to be • discharged to Snap Lake • Necessary for De Beers to continue sustainable operations at Snap Lake Mine that provide ongoing benefits to local communities and the economy of the Northwest Territories • De Beers has, for several years, presented water models have shown that TDS loading to Snap Lake is increasing due to mining, and that current water licence limits for whole-lake TDS and chloride in effluent will be exceeded without mitigation • Water licence renewed in 2012 required De Beers to propose new water quality objectives and effluent limits for TDS and other parameters for Snap Lake Mine based on aquatic toxicity studies The De Beers Group of Companies 1
Overview of Water Licence Amendment Applications - TDS Studies of the aquatic organisms of Snap Lake show that previous • licence limit for TDS was overly protective • Studies of mitigation technologies to reduce TDS loadings show that existing limits cannot be met using available technologies • Application also proposes minor regulatory and administrative changes • Proposed increases to TDS limits meet the requirements of the Mackenzie Valley Environmental Impact Review Board to prevent significant adverse impacts to fish, the aquatic environment, human health and traditional land use The De Beers Group of Companies 2
Overview of Water Licence Amendment Applications - TDS Water Quality Objective (WQO) • A concentration of a substance in water above which effects to aquatic health may occur • Protective of aquatic life in Snap Lake Effluent Quality Criteria (EQC) • Concentration of a substance in Outfall effluent that can be discharged without exceeding the WQO Effluent Mixing Zone The De Beers Group of Companies 3
Overview of Water Licence Amendment Applications - TDS Interim TDS Limits Life-of-Mine TDS Limits Proposed changes • Rescind whole-lake average 350 mg/L • Rescind whole-lake average 350 mg/L • SSWQO of 684 mg/L • SSWQO of 1,000 mg/L • EQC of 850 mg/L (average monthly) • EQC of 960 mg/L (average monthly) • Chloride regulated as part of TDS • Chloride, sulphate regulated as part of TDS • “unmitigated” plus current practice • RO-based water treatment, plus dilution, Mitigation to Meet Limits (storage, dilution, targeted grouting) targeted grouting Effective Period • As soon as possible (Q2) until LOM limit • Q3 2015 to end of licence term is determined (assume Q3 2015) Purpose • Allows mine to operate in compliance in • Long-term sustainable operation of Snap Lake Mine short term while mitigation is tested and LOM limit is set • Yes • Yes Meets Measures of EA1314-02 The De Beers Group of Companies 4
Overview of Water Licence Amendment Applications - TDS Near Diffusers TDS near diffuser SNP02-20e under Upper Bound and Lower Bound unmitigated scenarios Effective period of proposed interim SSWQO Proposed interim SSWQO 684 mg/L Proposed Life-of-mine SSWQO of 1,000 mg/L Current licence limit 350 mg/L The De Beers Group of Companies 5
Overview of Water Licence Amendment Applications - TDS Upper Bound Lower Bound 1,800 1,600 Total Dissolved Solids (mg/L) 1,400 1,200 1,000 800 600 400 Effluent 200 0 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 2024 2026 2028 Year TDS in effluent (SNP02-17B) under Upper Bound and Lower Bound unmitigated scenarios Effective period of proposed interim EQC Proposed interim EQC 850 mg/L Proposed Life-of-mine EQC of 960 mg/L The De Beers Group of Companies 6
Overview of Water Licence Amendment Applications - TDS • Decision on EA1314-02 to replace requirement to maintain TDS <350 mg/L in Snap Lake • Measures 1a-d require that SSWQO for TDS and constituent ions meet the following objectives: EA Measure How Met by Proposed Amendments 1a Aquatic system is protected SSWQO has been proposed based on technically defensible aquatic toxicity testing focused on resident species 1b Water in Snap Lake is safe to Nitrate, nitrite and fluoride in Snap Lake will not exceed drink (Health Canada) Health Canada’s Drinking Water Guidelines 1c Fish are safe to eat in Snap Lake TDS does not affect safety of fish consumption; AEMP and downstream monitoring will continue 1d TDS not detectable in Mackay Snap Lake TDS will not be detectable in Mackay Lake (will Lake (44 km) not cause changes outside of range of natural variability) The De Beers Group of Companies 7
Overview of Water Licence Amendment Applications - TDS • EA Measure 2 requires De Beers to implement water treatment or other mitigations to achieve the numerical SSWQO and associated EQC set by the MVLWB, which meet the objectives of Measure 1. EA Measure How Met by Proposed Amendment 2 Mitigation to be implemented Treatment of effluent will not be required to meet the to achieve SSWQO and EQC proposed interim SSWQO of 684 mg/L and EQC of 850 (interim) mg/L in the short term (2015); testing of mitigation will be completed Mitigation to be implemented Proposed SSWQO of 1,000 mg/L and EQC of 960 mg/L to achieve SSWQO and EQC can be met by treating a portion of effluent using RO- (LOM) based water treatment technology • De Beers’ proposal for TDS amendments is consistent with commitments made during EA1314-02 as listed in Appendix B of the report of EA. The De Beers Group of Companies 8
Overview of Water Licence Amendment Applications - TDS • De Beers has given due consideration to the MVEIRB’s Suggestions EA Suggestion How Taken into Consideration in Proposed Amendment 1 • De Beers proposes to submit an update to the AEMP Update AEMP Response Framework Design Plan within 1 year of amendment • De Beers proposes a Special Study to address data gaps and improve model certainty 2 • TDS in Snap Lake will return below aesthetic objective Water quality in Snap Lake to within 7 years achieve aesthetic objective 5 years post-mine operations 3 • BATEA for Snap Lake Mine concludes that RO-based Evaluate technologies using BATEA approach treatment is technologically, environmentally and economically viable to achieve proposed SSWQO The De Beers Group of Companies 9
Overview of Water Licence Amendment Applications - TDS The proposed interim SSWQO of 684 mg/L allows the mine to operate in compliance in the short term while mitigation is tested and LOM limit is set by the MVLWB The proposed TDS SSWQO of 1,000 mg/L is: 1. PROTECTIVE (not over-protective) 2. APPROPRIATE (based on site-specific studies) 3. ACHIEVABLE (can be met through mitigation) The De Beers Group of Companies 10
Supporting Documents – TDS Amendments Model Reports: (Groundwater Flow Model; Snap Lake Site Water Balance • Model; Site Water Quality Model; Snap Lake Hydrodynamic and Water Quality Model) • All reports of toxicity studies to establish Chronic Effects Benchmarks in support of SSWQOs TDS Response Plan • • Development of Effluent Quality Criteria (EQC) Report • Report on preliminary evaluation of BATEA for Snap Lake Mine • Responses to Information Requests: April 2014; May 2014; January 2015 • Engagement records filed December 2013, June 2014, November 2014, January 2015 (in-camera) All other materials filed as part of EA1314-02 during the joint MVLWB- • MVEIRB proceedings and MVEIRB proceedings The De Beers Group of Companies 11
Summary of Findings BATEA Study Treatment of mine effluent for removal of chloride is uneconomic • (HATCH 2014) • The BATEA study concludes that the protective TDS EQC for Snap Lake of 960 mg/L can be achieved using available technologies • Combined environmental and technical evaluation rates RO-based treatment as best available for Snap Lake Mine • Economic viability of RO technology at Snap Lake Mine depends on: 1. The TDS limits set by the Land and Water Board (how much treatment is required) 2. Future mine outflows (how much effluent needs to be treated) 3. The efficiency of the treatment (how much TDS can be removed) The De Beers Group of Companies 12
Mitigation to Meet Proposed EQC Un Under r Interi rim m EQC of 850 mg/L during ng 2015: 5: Allows mine to operate in compliance in short term while mitigation is tested • and life-of-mine limit is set • Continue with existing methods for managing TDS: storage; controlled dilution; targeted grouting • Implementation and testing of proof-of-concept Reverse-osmosis (RO) treatment unit arriving on winter road Un Under r Life-of of-Min Mine EQC of 960 mg/L (2015-2028) 028) • RO-based treatment of a portion of the effluent using a phased approach (progressive addition of treatment capacity and brine reduction) • Net reduction in TDS loading to Snap Lake by offsite disposal of solid waste brine • Complemented by controlled dilution and targeted grouting The De Beers Group of Companies 13
Next Steps - Implementation of RO Proof-of-Concept Phase RO module to arrive by winter road 2015 • Installation and commissioning in Q3 2015 • Life-of-mine EQC set in water licence • • Operation of the proof-of-concept RO system to gather important information about: Recovery efficiency o Optimized configuration o Design of brine minimization o • Decisions on design of subsequent phase(s) must be made Q3 2015 to complete designs by Q4 2015 The De Beers Group of Companies 14
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