Detour Lake Gold Mine Environmental Effects Summary. April Prepared by: Canadian Environmental Assessment Agency CEAR

Transcription

1 Detour Lake Gold Mine Environmental Effects Summary Prepared by: Canadian Environmental Assessment Agency CEAR

2 Introduction The purpose of this Environmental Effects Summary is to support public participation during the conduct of the federal environmental assessment (EA) of the Detour Lake Gold Mine (the project) under the Canadian Environmental Assessment Act (the Act). It provides a summary of the project, public participation and the results to date of the environmental effects assessment carried out by Detour Gold Corporation (Detour Gold). This document and Table-1 summarize: the project, the components of the environment that may be affected by the Project, the nature of that interaction and the proposed mitigation, the residual environmental effects after taking the mitigation into account, and the results of consultation undertaken to date The public is invited to review this document and provide comments on any aspect. However, the primary interest of the Agency is input on whether the EA process has addressed the important environmental issues and identified appropriate mitigation measures to avoid or reduce the environmental effects of the project. Comments received on the Detour Gold s analysis of the environmental effects of the project will be considered by the Canadian Environmental Assessment Agency (the Agency) when preparing a Comprehensive Study Report (CSR) that describes the project, its potential environmental effects, measures proposed to prevent or mitigate those effects and the significance of any residual environmental effects after taking into account the proposed mitigation. The CSR will be made available for public comment and then, along with any comments received, will be considered by the Minister of the Environment in reaching an EA decision. Project Background Detour Gold has been exploring the Detour Lake gold property since early 2007, and exercised its option to acquire the property in October The Detour Lake property is located approximately 140 kilometres (km) northeast of Cochrane in northern Ontario. An open pit and underground mine were operated by others on the property from 1983 to 1999, as the Detour Lake Mine. Detour Gold is proposing to redevelop the Detour Lake site as a high tonnage open pit mine and associated gold processing facility. All components of the project will be on lands leased by Detour Gold, or through claims on Crown land that will be secured through lease. Preference has been given to using lands disturbed by historic mining or forestry operations where siting options are otherwise equivalent. Page 2

3 FIGURE 1: PROJECT SITE LOCATION Page 3

4 Major project components include: the open pit mine; waste rock, low grade and overburden stockpiles; ore processing plant; crusher building; tailings impoundment area (TIA); construction and permanent accommodation complexes; ancillary buildings; mine site roads and pipelines; fuel storage and fuelling facilities; explosives factory and magazines; water supply and sewage treatment systems; on-site landfill; aggregate operations; construction diesel generators; and possibly a new airstrip. Mining and processing are projected to be carried out over 16 years, at an estimated ore throughput of 61,200 tonnes per day, based on a 24-hour per day, 365 days per year operating schedule. Access to the project site is provided by existing Highway 652 and an existing all-season gravel road. Detour Gold is also proposing to reconnect the project site to the provincial electrical grid. This would involve construction of a 135 km, 230 kilovolt transmission line from the project site to Island Falls, primarily within the previous transmission line right-of-way and a 40 km extension, paralleling the existing Hydro One transmission line corridor north from Island Falls to the Pinard Transformer Station. The project is expected to provide direct employment for a peak construction workforce of approximately 1,200, and will directly employ approximately 500 persons during operations. Subject to the receipt of environmental approvals, project construction is scheduled to continue through to the end of 2012, with gold production to commence on or about January 1, Further information regarding the project may be obtained from Detour Gold s website Federal Environmental Assessment Requirements An environmental assessment (EA) is required under the Canadian Environmental Assessment Act (the Act) before federal authorities may make certain decisions which would enable the project to be carried out. An EA is required for the project because: Fisheries and Oceans Canada (DFO) may issue authorization(s) pursuant to subsection 35(2) of the Fisheries Act for the harmful alteration, disruption or destruction of fish habitat; Fisheries and Oceans Canada (DFO) may issue authorization(s) pursuant to section 32 of the Fisheries Act for the destruction of fish by means other than fishing; The Governor in Council may amend Schedule 2 of the Metal Mining Effluent Regulations, pursuant to paragraphs 36(5) (a) to (e) of the Fisheries Act, to list one or more water bodies as tailings impoundment areas; Transport Canada may issue an approval pursuant to section 5 of the Navigable Waters Protection Act; and Natural Resources Canada may issue a license pursuant to section 7(1) of the Explosives Act. Page 4

5 The Agency determined that a comprehensive study is required because the project as proposed falls within three categories of projects described in the Comprehensive Study List Regulations: The proposed construction, decommissioning or abandonment of: a metal mine with an ore capacity of 4,000 tonnes per day or more; a gold mine other than a placer mine, with an ore production capacity of 600 tpd or more; and a facility for the extraction of 200,000 cubic meters per year (m 3 /a) or more of groundwater. Federal Environmental Assessment Responsibilities Minister of the Environment The Minister of the Environment is to consider the Comprehensive Study Report (CSR) and public comments received on the CSR. Once all necessary information has been provided, the Minister issues an EA decision statement that includes: the Minister s opinion as to whether, taking into account the implementation of any mitigation measures the Minister considers appropriate, the project is, or is not, likely to cause significant adverse environmental effects, and any mitigation measures or follow-up program that the Minister considers appropriate. Canadian Environmental Assessment Agency Pursuant to amendments to the Act that came into force in July 2010, the Agency is responsible for conducting the comprehensive study for the project until the Comprehensive Study Report is submitted to the Minister of the Environment. As Federal EA Coordinator, the Agency is also ensuring that federal authorities fulfill their obligations under the Act in a timely manner and is coordinating the federal EA process with the EA requirements of the Province to the extent possible. Federal Authorities In addition to providing input relevant to their respective potential regulatory approvals, Fisheries and Oceans Canada, Natural Resources Canada and Transport Canada are providing expert advice to the Agency in carrying out the comprehensive study. Environment Canada, Health Canada, and Indian and Northern Affairs Canada are also providing expert advice to the Agency on the comprehensive study. Provincial Environmental Assessment and Approvals Page 5

6 The project is subject to several provincial EA and regulatory requirements. Consistent with good environmental assessment coordination, the federal environmental assessment has considered information obtained during the provincial processes. As such, much of the information that has been used to complete the federal EA has been obtained from the provincial environmental assessment, including baseline studies and approval documents. Scope of the Project The scope of the project considered in this comprehensive study includes the physical works and activities associated with the construction, operation, modification and decommissioning/abandonment of the project as proposed by the Proponent. Details on the scope of the project and scope of factors for the purpose of the federal EA may be found in the Detour Lake Gold Mine: Scope of the Comprehensive Study under the Canadian Environmental Assessment Act (August 2010) which is posted on the Canadian Environmental Assessment Registry and may be accessed at: Stakeholder Engagement and Public Participation A program of stakeholder engagement and public participation is being carried out for the EA process, which includes components led by Detour Gold, the Province, and the Agency. Detour Gold, in coordination with the federal and provincial agencies, committed to a process of full and open dialogue with local and regional stakeholders and citizens, including Aboriginal groups, having an interest in the project. The Agency provided participant funding to Northwatch to assist in its review of environmental assessment documents and in providing input to the comprehensive study process. Results of public participation events held during the provincial EA process indicate there is strong support for the project in the local communities Aboriginal Consultation Aboriginal consultation by Detour Gold with respect to the project has involved discussions on the potential effects of the project on Aboriginal and treaty rights as well as current use of the lands and resources for traditional purposes. These discussions have occurred with the Moose Cree First Nation (MCFN), Taykwa Tagamou Nation (TTN), and the Wahgoshig First Nation (WFN); as well as the Métis who have asserted an interest in the project area, and the MoCreebec Council of the Cree who live in the Moose Factory area, and the Cree Regional Authority in Quebec who have also requested information on the project. Aboriginal groups were consulted through community meetings and workshops, and through the preparation of Traditional Knowledge (TK), Traditional Land Use (TLU) and archaeology studies. Detour Gold provided funding to the involved Aboriginal groups to undertake TK and TLU studies, and to hire technical experts to act on their behalf for EA review. Detour Gold used Page 6

7 information obtained from TK and TLU studies in assessing the environmental and socioeconomic effects of the project. The Agency provided funding to the Moose Cree First Nation, Taykwa Tagamou Nation, the Wahgoshig First Nation, the Métis Nation of Ontario and the Cree Regional Authority to assist in reviewing environmental assessment documents and in providing input to the comprehensive study. Aboriginal Groups in the area have expressed concern that their hunting and fishing practices could potentially be impacted by the project. Specifically, concern was expressed that the project may create new access into the area for non-aboriginal hunters and fishers; and that the associated increased in hunting and fishing may reduce wildlife and fish availability to their community members. Aboriginal Groups have also expressed concern about the impacts to surface and groundwater resources and closure plans. Detour Gold has proposed measures to limit the potential for any such effects, including prohibiting its employees and contractors from hunting or fishing when at the mine site. Aboriginal communities in the study area expressed strong interest in project related employment, training and economic development opportunities. In support of these objectives, Detour Gold has negotiated Impact Benefit Agreements with the MCFN, TTN and WFN, and has signed a Memorandum of Understanding with the Métis Nation of Ontario. Detour Gold has made commitments to hire from the local area and region. Additional consultation with Aboriginal groups will be coordinated by the Agency during the completion of the comprehensive study and upon release of the CSR. Potential Effects of the Project, Mitigation Measures and Residual Effects A summary of the results of Detour Gold s analysis of the potential environmental effects of the project is presented below. Environmental Effects All project-environment interactions were considered before focusing the assessment on valued ecosystem components (VECs) and valued socio-economic components (VSECs). The components that were selected on the basis of those aspects of the environment have particular value or sensitivity based on scientific data, traditional knowledge (TK), and in consideration of the comments received during the provincial EA processes. The VECs considered in the EA include: Air quality (including noise); Local watercourses and associated lakes; Groundwater system; Page 7

8 Terrestrial Habitat o Vegetation communities and associated terrestrial habitat linkages; o Moose and Caribou; o Large predators and furbearers; and o Migratory birds. Species At Risk Air quality was selected as a VEC because project related effects such as particulate matter and greenhouse gas (GHG) emissions from fuel combustion can have a detrimental effect on sensitive plant species, such as lichens. Lichens are an important food resource for Caribou, especially in winter. Particulate matter also provides a means for attached heavy metals to enter the environment. Noise emissions can disturb sensitive wildlife species such as Caribou. GHG emissions linked to fuel combustion are of concern from a climate change perspective. Local watercourses and associated lakes provide significant habitat for locally important species (mainly fish species). These systems constitute sensitive receiving water environments because they support productive aquatic communities and they are indicators of environmental health. These systems will potentially be influenced by one or more of the following: Direct discharge or seepage from the TIA effluent treatment works; Runoff and seepage release from waste rock stockpiles; Treated domestic sewage effluent discharge; Landfill leachate release; Open pit dewatering; Surface water or groundwater takings for process and potable water uses; Changes to watershed catchment characteristics; and Dust from road traffic and work on mineral stockpiles. The Karel Creek system is particularly noteworthy for providing Brook Trout habitat, which is regarded as a sensitive species with specific habitat requirements. The Detour River is the major system to which most of the local creek systems drain, except for the Deem Creek system which drains to the north. The Detour River system also meets a number of other VEC selection criteria because of its larger size and therefore greater regional importance, including its provision of habitat for Lake Sturgeon which is a species at risk. The Tailings Impoundment Area (TIA) Cell 2 Muskeg Pond and associated fen track drainage system comprises part of the East Creek system. This pond is regarded as a VEC solely because in order to deposit tailings into waters frequented by fish, the waterbody must be listed on Schedule 2 of the Fisheries Act, Metal Mining Effluent Regulations. The local groundwater system is regarded as a VEC within the context of providing baseflow to local creek systems, particularly through groundwater / surface water linkages associated with glaciofluvial features (eskers, esker-like deposits and glacial outwash features). Page 8

9 Vegetation communities and associated terrestrial habitat linkages provide, or can potentially provide: Areas of notable biological diversity; Significant habitat for locally important species; Significant habitat for uncommon, rare or unusual species; Important corridors or linkages for wildlife movement; Indicators of environmental health; and Important components of other ecosystem elements or functions. There are no rare or unusual plant communities in the project area, but the importance of Black Spruce Jack Pine forests and their associated lichen communities to overwintering Caribou populations is noteworthy. Moose and Caribou are regarded as notable species in their own right because of their importance as a hunting resource to all persons in the region (Moose) and to Aboriginal hunters (Moose and Caribou). Caribou are also a SAR, and are hence regarded as indicators of environmental health. Large predators, furbearers and migratory birds comprise important niches in the function of other ecosystem components, and are of economic and cultural significance. Identified Species at Risk in the project site and transmission line right-of-way includes Woodland Caribou, Bald Eagle, Olive-sided Flycatcher, Rusty Black Bird, Lake Sturgeon, Monarch Butterfly and Common Nighthawk. Other Species at Risk are known from the general region but are less likely to occur in the immediate Project area. Five VSECs considered in the EA include: Land use and resource use: Hunting, Fishing and Outfitting Commercial Operations; Traditional land use: Resource Harvesting Cultural Sites / Areas; and Public health and safety. These VSECs are biophysically linked to aspects of the natural environment that could potentially be affected by the project. Predicted Environmental Effects An environmental effect was assessed on the basis of the sensitivity of the system/component or feature potentially affected; the nature of the effect on that system/component or feature; the likelihood of the effect occurring, proposed mitigation measures to eliminate or reduce the effect; and the magnitude, geographic extent, duration, frequency and reversibility of any residual effect after taking mitigation into account. Page 9

10 Detour Gold predicts that the project will meet applicable provincial standards for air quality and noise effects, following the application of proposed mitigation measures. Mitigation measures include limited use of diesel generation and dust suppression on haul roads and within the mill. Subject to further evaluation, it is anticipated that with mitigation, predicted air quality and noise levels will be consistent with provincial regulatory requirements and any minor effects from construction and operation will cease following mine closure. Similarly, no adverse effects on local watercourses and associated lakes from discharges of the TIA and site runoff are anticipated if federal and provincial water quality standards and the requirements for the protection of aquatic life are met. The project is a large tonnage operation; hence the quantity of effluent discharged by the mill will be correspondingly large. To protect local watercourses and associated lakes, Detour Gold is proposing to use the SO 2 /Air process for cyanide destruction and heavy metal precipitation before mill effluent is discharged to the TIA; use extended effluent aging in the TIA ponds to further improve effluent quality; use maximum rates of recycled water from the TIA for re-use in the processing plant; and restrict the direct discharge of final TIA effluent to the environment to treated mine water. Mine water with elevated ammonium levels, produced from blasting, will be treated through a natural biological process of nitrogen decomposition within the TIA prior to any discharge into a receiving watercourse. Effects to local fish habitat are expected as a result of TIA construction and the predicted reduction of flows in creeks adjacent to the open pit. Based on the submission of Detour Gold s conceptual fish habitat compensation plans, but subject to further evaluation and refinement, Detour predicts that the proposed mitigation measures can achieve no net loss of productive capacity of fish habitat as prescribed in DFO s Policy for the Management of Fish Habitat (1986). Residual effects to fish habitat such as increased and/or decreased streamflows are predicted to be minor and temporary. The management of acid rock drainage potential is a critical component for environmental protection, dictated in part by the scale of proposed operations. Detour Gold believes that the tailings are not expected to be acid generating. However, up to approximately 20% of the waste rock may be acid generating. General drainage from waste rock and overburden stockpiles will be managed using vegetated buffers to remove suspended solids, together with runoff and seepage collection systems as appropriate. Local groundwater resources, particularly those adjacent to waste stockpiles and the TIA, will also be a focus of mitigation measures, including adaptive environmental management planning. Areas downgradient of potentially acid generating rock, will be actively managed, seepage water will be collected and treated to meet all applicable water quality standards. Terrestrial habitats will be affected, with up to approximately 23 km 2 of existing forest habitat to be removed, or displaced, as a result of mine site development and transmission line construction. Habitat removal will affect local wildlife species; but all of the habitats that are to be removed or displaced are commonplace in the local and regional environment, and are located Page 10

11 in close proximity to existing disturbed areas. There will be no new access to currently undisturbed areas. Residual effects are anticipated to be minor and reversible following the implementation of the mine decommissioning plan. The potential for adverse effects to Woodland Caribou has been identified by Detour Gold as the primary concern. To minimize adverse effects on Caribou, Detour Gold has proposed as compact a mine site as practicable, focusing developments on previously disturbed areas, and avoiding the development of new roads in currently inaccessible areas. Measures planned for site restoration at closure include development of habitats suitable to wildlife in general, and to Caribou in particular. Detour Gold has determined that there will be adverse effects to Caribou habitat, but because Caribou occur at low densities and exhibit such large ranges, the number of directly affected individuals is expected to be small. Subject to further evaluation, effects to Species at Risk, including Caribou, are likely to be minor and reversible following implementation of the mine decommissioning plan. Detour Gold predicts that adverse environmental effects to the VSECs are not likely to occur, including potential adverse effects to traditional land use. A number of positive socio-economic effects are predicted in relation to employment and business opportunities, including those expected to accrue to Aboriginal groups, through their signed Impact Benefit (or equivalent) Agreements with Detour Gold. Such Agreements are beyond the scope of this EA, but are central to Aboriginal interests. Cumulative Environmental Effects Detour Gold considered how the effects of its project could combine with past, present or future (reasonably foreseeable) projects. The effects remaining from earlier mining activities were accounted for in the description of the existing environment and considered during the planning and assessment of the future mine operations. Detour Gold has identified only one planned project apart from the project within the local study area. A small quarry is planned to be re-opened near the western end of the project s all-season gravel access road. Details regarding the quarry operations have not been defined; however, the quantity of rock extraction is expected to be modest. Rock extraction at the planned quarry is too far removed from the project site to contribute to cumulative environmental effects associated with the mine site. However, activities associated with the quarry operations may add to traffic noise and road dust effects associated with use of the existing project access road. There are no planned forest harvest operating areas for the applicable Sustainable Forest Unit identified until 2012 and the Ministry of Natural Resources has deferred any such potential operations in the area surrounding and near to the project area until such time as the anticipated Provincial Caribou habitat regulation has been released and assessed relative to regional forestry operations. Page 11

12 With regard to possible additional mineral resources, Detour Gold singularly and in a joint venture partnership with Tradewinds Ventures Inc., has identified gold mineralized zones extending west from the planned project open pit. Whether or not these mineralized zones support sufficient resources to warrant advanced exploration and commercial production remains to be determined. When and if such resources (and projects) are identified, separate EA studies may be required to determine the likely environmental effects. Follow-up Program and Monitoring In accordance with the Act, the Follow-up Program is designed to verify the accuracy of EA predictions and determine the effectiveness of mitigation measures. It can also support the implementation of adaptive management strategies designed to respond to unanticipated environmental effects. Responsible Authorities ensure that all appropriate mitigation measures are implemented and ensure the implementation of any Follow-up Program requirements identified in the CSR. To fulfill this obligation, responsible authorities may rely on commitments made through provincial actions, commitments made by the proponent or their own regulatory actions. For this comprehensive study, follow-up program components in relation to air quality and noise; surface water systems; groundwater systems; wildlife; Species at Risk; public health and safety; culturally significant features and areas; and traditional land use are being considered. Where monitoring commitments made through the EA process are not covered by specific federal or provincial regulatory instruments, an environmental agreement may be developed between the federal and provincial authorities, Detour Gold, and potentially other parties. Page 12

13 Standard Glossary Detour Lake Gold Mine Note - not all terms may appear in the summary or Table-1 A AMEC Amsl ANFO ANSI ARD CDSSAB CEA Agency CEAA CEAR CN WAD CO CO 2 CSQG CSR CEQG dba Detour Gold DFO DLP DLM EA EAG EC EPP EPT ERS ESA ESR FA FWCA GHG ha HC INAC km km 2 LSA m m 3 m 3 /a m 3 /d MAFA MBCA annum AMEC Earth & Environmental above mean sea level ammonium nitrate fuel oil area of natural and scientific interest acid rock drainage Cochrane District Social Services Administration Board Canadian Environmental Assessment Agency Canadian Environmental Assessment Act Canadian Environmental Assessment Registry Weak acid dissociable cyanide carbon monoxide carbon dioxide Canadian sediment quality guidelines comprehensive study report Canadian environmental quality guidelines A-weighted decibels Detour Gold Corporation Fisheries and Oceans Canada Detour Lake Project Detour Lake Mine environmental assessment Environmental Applications Group Environment Canada environmental protection plan Ephemeroptera - Plecoptera - Trichoptera emergency response strategy Endangered Species Act Environmental Study Report Federal authority Fish and Wildlife Conservation Act greenhouse gas hectare Health Canada Indian and Northern Affairs Canada kilometre square kilometre local study area metre cubic metres cubic metres per year cubic metres per day Moose aquatic feeding areas Migratory Birds Convention Act Page 13

14 MBR MCFN MERC mg/l mm Mm 3 MNDMF MNO MNR MOE MRS Mt Mt/a MW NAG NOx NRCan AAQC ODWS PAG PMF PSQG PWQO RA ROW RSA SAR SARA SO 2 t TC TIA TEK TK TLU tpa tpd TS TSS TTN VEC VSEC WFN WHS WMU WSC membrane bioreactor Moose Cree First Nation Mushkegowuk Environmental Research Centre milligrams per litre millimetre Million cubic metres Ministry of Northern Development, Mines and Forestry Métis Nation of Ontario Ministry of Natural Resources Ministry of the Environment waste rock (or mine rock) stockpiles million tonnes million tonnes per year Megawatts non-acid generating nitrogen oxides Natural Resources Canada Ontario Ambient Air Quality Criteria Ontario Drinking Water Standards potentially acid generating probable maximum flood Provincial Sediment Quality Guideline Provincial Water Quality Objectives responsible authority right-of-way regional study area species-at-risk Species at Risk Act sulphur dioxide tonne Transport Canada tailings impoundment (or tailings management) area Traditional Ecological Knowledge Traditional Knowledge Traditional Land Use tonnes per annum (year) tonnes per day transformer station total suspended solids Taykwa Tagamou Nation valued ecosystem component valued socio-economic component Wahgoshig First Nation Woodland Heritage Services Limited Wildlife management unit Water Survey of Canada Page 14

15 Table 1 - Environmental Effects Summary Table System / Component / Feature NATURAL ENVIRONMENT Air Quality, Noise and Air emissions from the project site GHGs have the potential to generate dust and other contaminants that Air Quality could potentially affect human health, and plant and animal health; lichens which are an important food source for Caribou are sensitive to both dust and to Air Quality, Noise and GHGs Noise Air Quality, Noise and GHGs GHGs Local watercourses and associated lakes East Creek / Sunday Creek System Local watercourses and associated lakes Karel Creek System Potential Effect Proposed Mitigation Ecological and/or Social / Cultural Context SO 2 /Air emissions. Noise emissions have the potential to disturb other area users, as well as to disturb sensitive wildlife such as Caribou. Greenhouse gases associated with Project construction and operation have a minor potential to contribute to global CO 2 emissions and the associated phenomenon of climate change. TIA development and effluent discharge have the potential to reduce downstream flows, and to adversely affect water quality. Open pit and mineral stockpile development have the potential to alter creek flows - especially base flows in the case of open pit operations; potential for ARD and TSS loadings from waste rock stockpiles. Use of transmission line power to eliminate the need for diesel generation at site, except during the construction phase; water sprays and other dust suppressant measures; use bag houses and other measures to reduce dust from plant activities such as ore crushing. Maintaining tree screens around work areas as practical; mufflers and engine skirts to be used as appropriate to reduce sound levels at source; mineral stockpiles to provide shielding; enclosing of crushing equipment; and maintaining heavy equipment in good working order. Use of transmission line power as opposed to onsite diesel power; reducing transport needs (and hence fuel consumption) through development of a compact site; using larger more fuel efficient trucks; insulating buildings; maintaining equipment and vehicles in good working order. In-plant SO 2 /Air treatment will be used for cyanide destruction and heavy metal precipitation, followed by extended effluent aging (natural degradation) and extensive effluent reclaim. A contingency exits for TIA seepage collection, if required. The North Aggregate Pit will be closed out to provide compensatory Brook Trout spawning habitat connected to Karel Creek. Overwintering pools will be developed within Karel Creek. ARD potentials will be managed through segregation and later collection. TSS contained in mineral stockpile runoff will be managed through the use of vegetated buffer zones border Karel Creek. use of arched culverts at haul road crossings. Adverse effects involve human health, and locally and regionally important species (especially Caribou) and communities. Adverse effects involve locally and regionally important species (especially Caribou). Climate change has the potential to positively and negatively affect species and habitats on a global scale. Adverse effects would involve commonplace and widespread ecological communities; no known critical or limited habitats. Karel Creek is the only known cold water creek system in the immediate project site area, and is known to support Brook Trout. Residual Effects After Mitigation Magnitude / Duration Frequency Reversibility Geographic Extent With mitigation, predicted air quality consistent with provincial regulatory requirements. With mitigation, predicted noise levels expected to be consistent with provincial regulatory requirements, and with the buffer zone set for Caribou disturbance. The ability of Project related emissions to affect climate is negligible. Changes in system water flows are not expected to adversely affect downstream fish habitat; MMER, CEQG and PWQO effluent and water quality requirements (or background) are expected to be met. Potential adverse effects to Brook Trout spawning and overwintering habitats will be offset by proposed fish habitat compensation measures. Life of Project. Life of Project. Life of Project. Effects will persist mine operation. Effects will persist mine operation and well beyond closure. Effects expected to occur regularly or continuously. Effects expected to occur regularly or continuously. Effects expected to occur regularly or continuously. Direct effluent discharges expected to be intermittent - seasonal. Seepage and watershed flow effects would be continuous. Effect is expected to be continuous. Emissions will cease at mine closure. Emissions will cease at mine closure. Emissions will cease at mine closure. Effects are substantially reversible following TIA closure. Effects substantially reversible following mine closure, and passive filling of the open pit, but this action will take several decades. Overall Residual Effects is minor, and applicable standards will be met. Effects is minor, and applicable standards will be met. Magnitude of effect is too small to be measured. Overall effects of minor, localized and reversible. Overall effect minor and can be compensated for, with compensation measures expected to provide ecological function into the foreseeable future. Likelihood of Residual occur to varying degrees. Page 1 of 5 Draft Environmental Effects Summary Table original prepared by AMEC for Detour Gold, revised for presentation purposes by the Canadian Environmental Assessment Agency

16 System / Component / Feature Local watercourses and associated lakes Easter Creek System Local watercourses and associated lakes Linden Creek System Local watercourses and associated lakes Lindbergh Creek System Local watercourses and associated lakes Deem Lake System Local watercourses and associated lakes Detour River Local watercourses and associated lakes Muskeg Ponds Potential Effect Proposed Mitigation Ecological and/or Social / Cultural Context Watershed flow effects are considered Creek system and to be minor and do not require associated Easter Lake mitigation; TIA seepage to be provide generally controlled through use of in-plant commonplace habitats and cyanide destruction and heavy metal support cool water fish precipitation, with the contingency for communities. seepage collection if required. TIA development will alter watershed boundaries; open pit and waste rock stockpile development have the potential to alter creek system flows; TIA seepage and drainage from the overburden stockpile have the potential to affect creek water quality. Open pit and waste rock stockpile development have the potential to alter creek system flows; drainage from waste rock stockpile #2 has the potential to affect Linden Creek water quality. Water take and sewage treatment discharge associated with permanent operations camp; construction of transmission line and possible gravel airstrip resulting in potential sediment release. Waste stockpile development has the potential to alter drainage system flows; drainage from the waste rock stockpile has the potential to affect Deem Lake water quality. TIA discharge has the potential to affect Detour River water quality. Development of TIA Cell #2 will displace a small muskeg pond and its associated fen track drainage; this is an MMER Schedule 2 consideration. PAG materials will be directed away from waste rock stockpile #2 to control ARD; a minimum 120 m wide vegetation buffer zone will be maintained around the waste rock stockpile perimeter to control TSS migration; contingencies are in place to provide perimeter ditching and stormwater detention ponds if required to further manage TSS migration. Use of membrane bioreactor (MBR) for sewage treatment, and use of settling ponds for runoff control from airstrip if constructed; retention of plant ground cover for transmission line. PAG materials will be directed away from that portion of waste rock stockpile #1 that drains to the Deem Lake system; a minimum 120 m wide vegetation buffer zone will be maintained around the waste rock stockpile perimeter to control TSS migration; contingencies are in place to provide perimeter ditching and stormwater detention ponds if required to further manage TSS migration. In-plant effluent treatment and aggressive water volume management would be used to control TIA effluent discharge. The muskeg pond will be replaced with like for like habitat, and will be connected to a natural fen track. Creek system and associated Walter Lake provide generally commonplace habitats and support cool water fish communities. Creek system and associated Little Hopper and Lindbergh Lakes provide generally commonplace habitats and support cool water fish communities. Deem Lake and its associated creek system provide generally commonplace habitats and support cool water fish communities. The Detour River supports a number of fish species including Lake Sturgeon (a SARA species). The muskeg pond has limited fisheries values, but is of administrative significance because of the MMER Schedule 2 implications. Residual Effects After Mitigation Magnitude / Geographic Extent Duration Frequency Reversibility Watershed flow effects expected Watershed alteration Effect is expected Water quality effects to be minor (within 15% of flow due to TIA development to be continuous. will be reversible in the norms); MMER, CEQG and will be permanent. Other longer-term following PWQO effluent and water quality effects will persist closure. Watershed requirements (or background) are flow effects are not expected to be met. mine operation and well reversible. beyond closure. Changes in system water flows expected to be substantially less 15% of annual flow rates; MMER, CEQG and PWQO effluent and water quality requirements (or background) would be met. Water take expected to be <1% of average annual flows at outlet from Little Hopper Lake; MBR plant is best available technology able to meet federal and provincial effluent quality requirements; runoff from airstrip to be managed with settling pond(s). Changes in system water flows expected to be substantially less than 15% of annual flow rates; MMER, CEQG and PWQO effluent and water quality requirements (or background) would be met. PWQO and CEQG water quality requirements (or background) would be met in the Detour River. Potential adverse effects to the muskeg pond fish habitat will be offset by proposed fish habitat compensation measures. Effects will persist mine construction and operation. Effects will persist mine construction and operation. Effects will persist mine construction and operation. Effects will persist mine operation. Effects will be permanent. Effect is expected to be continuous. Effect is expected to be continuous. Effect is expected to be continuous. Seasonal discharges from the TIA will occur in most years of operations. Effect is expected to be continuous. Flow effects expected to be reversible following mine closure and flooding of the pit; water quality effects associated with TSS and ammonia release would also cease at mine closure; minor geochemical reactivity would continue for the foreseeable future, but is not expected to pose a concern. Effects are reversible following mine closure. Water quality effects associated with TSS and ammonia release would cease at mine closure; minor geochemical reactivity would continue for the foreseeable future, but is not expected to pose a concern. Water quality effects are expected to be reversible at mine closure. Effects will be permanent. Overall Residual Overall effects are minor and consistent with regulatory limits and guidelines. Overall effects of minor, localized and substantially reversible. Overall effects of minor, localized and reversible. Overall effects of minor, localized and substantially reversible. Overall effects of minor and reversible. Overall effect minor and compensation measures are expected to provide ecological function into the foreseeable future. Likelihood of Residual Page 2 of 5 Draft Environmental Effects Summary Table original prepared by AMEC for Detour Gold, revised for presentation purposes by the Canadian Environmental Assessment Agency

17 System / Component / Feature Groundwater System Terrestrial Habitat Natural Vegetation and Terrestrial Habitat Linkages Terrestrial Habitat Caribou and Moose Terrestrial Habitat Large Predators and Furbearers Potential Effect Proposed Mitigation Ecological and/or Social / Cultural Context Open pit dewatering has the Mitigation measures related to potential Groundwater/surface water potential to draw down local open pit dewatering effects on surface interactions are considered aquifers. Groundwater quality water systems are described above. above. There are no local would not be affected. There are No other mitigation measures are groundwater users. no groundwater users in the area. proposed. Mine site development will displace an estimated 20 km 2 of forest habitat, including 5.6 km 2 of Black Spruce - Jack Pine forest. An additional approximately 3.26 km 2 of undisturbed forest habitat will be cleared for transmission line construction. Minor disruption to terrestrial habitat linkage is possible for wildlife species that might tend to avoid the mine site area, much of which is already disturbed. The transmission line would follow along existing corridors over the majority of its length. Mine site development will displace an estimated 20 km 2 of forest habitat, including 5.6 km 2 of Black Spruce - Jack Pine forest, together with an additional 3.26 km 2 of undisturbed forest habitat associated with transmission line construction. Additional effects potentially associated with general disturbance and vehicular collisions. All-season road access to the project site already exists. Mine site development will displace an estimated 20 km 2 of forest habitat, with the resultant displacement of those large predators and furbearers that occupy the habitat. An additional 3.26 km 2 of undisturbed forest habitat associated with transmission line construction will also be disturbed, but will still provide ground and shrub habitat. Efforts made to develop a compact site, centred on previously disturbed habitat to limit disturbance to new areas; avoidance of riparian and other sensitive habitats to the extent practicable; site revegetation at closure to restore habitats, including the potential to develop lichen habitat on waste rock stockpiles. The transmission line will be constructed on or immediately adjacent to existing ROWs. Efforts made to develop a compact site, centred on previously disturbed habitat to limit disturbance to new areas; avoidance of riparian and other sensitive habitats to the extent practicable; site revegetation at closure to restore habitats, including the potential to develop lichen habitat suited to Caribou on waste rock stockpiles; the transmission line to be constructed along or adjacent to existing ROWs. Efforts made to develop a compact site, centred on previously disturbed habitat to limit disturbance to new areas; avoidance of riparian and other sensitive habitats to the extent practicable; site revegetation at closure to restore habitats. The transmission line is to be constructed along or adjacent to existing ROWs. Adverse effects would generally involve commonplace and widespread species. Caribou are recognized as a SAR by both the provincial and federal governments. Moose populations appear to be holding their own. Adverse effects would generally involve commonplace and widespread species. Residual Effects After Mitigation Magnitude / Geographic Extent Duration Frequency Reversibility Effects very Effects will persist Effect is expected Effects substantially localized, within a few hundred to be continuous. reversible following metres of the pit perimeter at mine operation and well mine closure, and most, and would not conflict with beyond closure. passive filling of the other users (none present). open pit, but this action will take several Effects minor (5.6% of LSA in the case of the project) and confined to the immediate mine site area. Wildlife species prone to avoid the mine site area most likely already do so. Vegetation clearing associated with the transmission line considered to be minor and directly associated with previously disturbed areas. Effects minor (5.6% of the mine site LSA) and confined to the immediate mine site area; together with 0.9% of the transmission line LSA). Available data suggest that the carrying capacity for 0.23 individual Caribou would be involved, but if general disturbance effects are considered, the potential exists to affect a further small number of individuals at some level. Effects minor (5.6% of LSA; together with 0.9% of the transmission line LSA) and confined to the immediate mine site area, or to existing ROWs in the case of the transmission line. Wildlife species prone to avoid the mine site area most likely already do so. persist mine development, and it will take some time for forest habitats to reestablish following active rehabilitation at mine closure. Vegetation recovery along the transmission line will be faster because of the presence of intact ground cover and tree seedlings. persist mine development, and it will take some time for wildlife habitats to reestablish following active rehabilitation at mine closure. Wildlife habitat recovery along the transmission line will be faster because of the presence of intact ground cover and tree seedlings. persist mine development, and it will take some time for forest habitats to reestablish following active rehabilitation at mine closure. Wildlife habitat recovery along the transmission line will be faster because of the presence of intact ground cover and tree seedlings. Effect is expected to be continuous. Effect is expected to be continuous. Effect is expected to be continuous. decades. Effects are reversible following mine closure. Effects are reversible following mine closure. Effects are reversible following mine closure. Overall Residual Overall effect minor. Overall effects generally minor, localized and reversible. Overall effects of generally minor, localized and reversible. The project site is a brown-field site with existing road access. The transmission line will be constructed along and adjacent to existing ROWs. Overall effects of generally minor, localized and reversible. The project site is a brown-field site with existing road access. The transmission line will be constructed along and adjacent to existing ROWs. Likelihood of Residual Page 3 of 5 Draft Environmental Effects Summary Table original prepared by AMEC for Detour Gold, revised for presentation purposes by the Canadian Environmental Assessment Agency

18 System / Component / Feature Terrestrial Habitat Migratory Birds Species at Risk Lake Sturgeon Species at Risk Potential Effect Proposed Mitigation Ecological and/or Social / Cultural Context Mine site development will Efforts made to develop a compact Adverse effects would displace an estimated 20 km 2 of site, centred on previously disturbed generally involve forest habitat, with the resultant habitat to limit disturbance to new commonplace and displacement of migratory birds areas; avoidance of riparian and other widespread species, that would typically occupy such sensitive habitats to the extent together with some SAR habitat. An additional 3.26 km 2 of practicable; avoidance of tree clearing and regionally rare species. undisturbed forest habitat during the bird nesting season; site associated with transmission line revegetation at closure to restore construction will also be habitats. The transmission line is to be disturbed, but will still provide constructed along or adjacent to ground and shrub habitat. existing ROWs. TIA discharge has the potential to affect Detour River water quality. Lake Sturgeon reside in the Detour River. In-plant effluent treatment, coupled with extended effluent aging, and extensive water recycle would be used to control TIA effluent discharge. Addressed above under the heading Caribou and Moose. The Detour River supports a number of fish species including Lake Sturgeon (a SARA species). Residual Effects After Mitigation Magnitude / Geographic Extent Duration Frequency Reversibility Effects minor persist Effect is expected Effects are reversible (5.6% of LSA; together with 0.9% to be continuous. following mine closure. of the transmission line LSA) and mine development, and confined to the immediate mine it will take some time for site area, or to existing ROWs in forest habitats to reestablish the case of the transmission line. following active Several of the SAR and rehabilitation at mine regionally rare species observed closure. at the project site were Habitat recovery along associated with riparian and the transmission line will disturbed habitats. be faster because of the presence of intact ground cover and tree PWQO and CEQG (or background) would be met in the Detour River. seedlings. Effects will persist mine operation. Effect is expected to be continuous. Water quality effects are expected to be reversible at mine closure. Overall Residual Overall effects of generally minor, localized and reversible. The project site is a brown-field site with existing road access. The transmission line will be constructed along and adjacent to existing ROWs. Overall effects of minor and reversible. Likelihood of Residual Woodland Caribou Species at Risk Migratory Birds Addressed above under the heading Migratory Birds. Page 4 of 5 Draft Environmental Effects Summary Table original prepared by AMEC for Detour Gold, revised for presentation purposes by the Canadian Environmental Assessment Agency