Mary River Project Phase 2 Proposal Freshwater Environment Technical Meetings April 8-10, 2019 Mary River Project Phase 2 Proposal Freshwater Environment

Introduction & Overview Confidential

Valued Ecological Components Freshwater Quantity and Quality Potential effects on water quantity and quality due to changes in sedimentation rates, hydrology, metal concentrations; and water flows via withdrawals and diversions. Freshwater Biota and Habitat Potential effects on health and condition of Arctic char Potential effects on habitat of Arctic char Potential effects on risk of mortality of Arctic char

Community Feedback A total of 35 comments or questions related to the Freshwater Environment 20 related to Groundwater and Surface water 12 related to Freshwater Aquatic Environment 3 related to Hydrology and Hydrogeology

IQ and Engagement Influence Switch from road to rail to address concerns related to effect of fugitive dust emissions on drinking water sources and fish Switch from outdoor secondary crushing at the Mine Site to development of indoor secondary crushing at Milne Port, to address concerns related to effect of fugitive dust emissions on drinking water sources and fish IQ interviews included focus on fish IQ provided baseline information on fish species Spatial boundaries for fish and fish habitat determined in consideration of IQ on distribution of Artic char Monitoring programs revised based on information from local community members, including the extension of programs to Ragged Island, and the analysis of more fish

Summary of FEIS Results Confidential

Summary of Effects Assessment VEC/VSEC Characterization of Residual Effect(s) Significance Rating Freshwater Quantity and Quality Overall, the residual effect of the Project on freshwater quantity and quality is predicted to be: Adverse in direction, with the exception of a positive direction on water quality at the Mine Site due to changes associated with secondary ore processing; Low in magnitude given planned mitigation and the small footprint affected relative to the watershed scale in the region; Geographically confined to the LSA; Infrequent effects are associated with the water withdrawals and continuous effects are associated with the stream diversions and water/sediment quantity and quality alterations; Of a duration that will occur throughout the life of the Project; and Reversible with additional mitigation and the cessation of Project activities. There is a high probability of the residual effects occurring. In consideration of the information available and the results of ongoing monitoring related to freshwater quantity and quality, there is a high level of confidence in the residual effects predictions for freshwater quantity and quality. Not significant Freshwater Biota and Habitat Overall, the residual effects of the Project on freshwater biota and habitat are predicted to be: Adverse in direction; Low in magnitude given planned mitigation and the small footprint effected relative to available habitat in the region; Infrequent effects are associated with the water withdrawals and continuous effects are associated with the habitat and water/sediment quantity and quality alterations; Reversible with mitigation and the cessation of Project activities. There is a high probability of the residual effects occurring. In consideration of the information available and the results of ongoing monitoring related to freshwater biota and habitat, there is a high level of confidence in the residual effects predictions.

Data History What has been done since Ongoing hydrometric monitoring (6 stations) Updated peak flow analysis for designing infrastructure Baseline water and sediment quality sampling (2012 to 2014) Baseline review (2005 to 2013) and development of an Aquatic Effects Monitoring Plan (AEMP) Aquatic effects monitoring (2015 to 2018) Annual tote road fisheries monitoring 2018 fisheries survey of North Railway crossings Future: A spring freshet fisheries survey of the North Railway is planned for late June 2019

Management Plans, Mitigation and Monitoring Confidential

Management Plans, Mitigation and Monitoring Freshwater Example Updates (detailed updates available in Commitment Register) Surface Water and Aquatic Ecosystems Management Plan Update mitigation measures to address the effects on streams receiving diverted flows, and mitigation measures to address fish passage at select culvert crossings along the North Railway Update mitigation measures for exposed soils, sedimentation, erosion, dust suppression, stream crossings, flow diversions, and fish habitat Update water management plans for site drainage, laydowns, soil stockpiles, soil disposal areas rock cuts, quarries, mine effluent, flow diversions, watercourse crossings, and dust suppression Add monitoring and inspections for the railway Update existing conditions and proposed development Fresh Water Supply, Sewage and Wastewater Management Plan Describe water supply to temporary camps (part of Water License Amendment Application) Inclusion of additional mitigation measures related to additional water supply Update to reflect new infrastructure and water quality monitoring locations Address water management changes with new ore stockpiles Snow Management Plan  Additional details and updates regarding infrastructure (e.g., new snow stockpile locations) Inclusion of North Railway Snow Management Guidelines Environmental Protection Plan (EPP) Add mitigation measure to minimize changes to the hydrologic drainage patterns Add additional design considerations for culvert installation/replacement Updates related to the construction and operation of the North Railway Water quality monitoring during construction of the second ore dock

Information Request and Technical Comment Review Confidential

Information Requests

Technical Comments – Freshwater Environment

Technical Recommendations Summary Technical Recommendation Category Main Issues Recommendation IDs Summary of Response Surface Water and Sediment Quality Acid rock drainage potential of quarries and rock cuts Mitigation of acid rock drainage at the existing Waste Rock Stockpile Effects on water quality due to changes in sedimentation rates ECCC 3.19, 3.20, CIRNAC 7, 8, 9   CIRNAC 5, 6 Baffinland provided a summary of testing results from 76 tests of rock and overburden along the railway. All samples are non-ARD and unlikely to leach metals. Baffinland will not use only % total Sulphur to screen rock for acid generating potential Baffinland provided an update on ongoing ARD/ML and permafrost encapsulation studies on the Waste Rock Facility Baffinland responded to earlier IRs/TRCs in January 2019 on water quality in Camp Lake relative to drinking water standards, and metals concentrations in Phillips Creek due to dust deposition at Milne Port Water Quantity Effects on water quantity due to changes in hydrology and water flows related to withdrawals and diversions. DFO (various; listed below) Baffinland directed DFO to FEIS information on fish habitat of lakes to be used for water withdrawals Provided substantiation of the water withdrawal thresholds used on streams (discussed below under freshwater fish) Confidential

Technical Recommendations Summary Technical Recommendation Category Main Issues Recommendation IDs Summary of Response Freshwater Fish, Fish Habitats and Other Aquatic Organisms Effects on the health and condition, habitat, and risk of mortality of Arctic Char due to: Construction of the North Railway Water withdrawals for dust suppression activities Sediment inputs from ore production, transport and related activities DFO 3.10.1 to 3.10.3 DFP 3.12.1 DFO 3.12.2 and 3.12.3 QIA 41 DFO requested additional details on watercourses that will be provided in a Supplemental Information Package submitted to the NWB on May 1, 2019. Requested fish habitat information for water withdrawal lakes (found in FEIS Volume 7, Appendix 7C) Additional information provided regarding water withdrawal thresholds Additional discussion provided on sedimentation, as addressed in TSD 14; Baffinland to discuss expansion of the Tote Road Monitoring Program in future to include selected water crossings on the rail alignment. Confidential