Executive Summary

1.0  INTRODUCTION

This Environmental Assessment (EA) was prepared by AGRA Earth & Environmental Limited (AGRA), pursuant to the requirements of the Canadian Environmental Assessment Act (CEAA) for Comprehensive Studies involving minerals and mineral processing facilities. The EA was prepared on behalf of Echo Bay Mines Ltd. (Echo Bay), as the Project proponent. In preparing the EA, AGRA was assisted by data, or inputs, from the following contributors: Echo Bay; Golder Associates Ltd. (Golder); Howe Gastmeier Chapnik Limited (HGC); Hydrologic Consultants Inc. (HCI); Kilborn Inc. (Kilborn); Knight Piesold; Layne Christensen Company (Layne); and Trow Consulting Engineers Ltd. (Trow).

1.1  Project Overview

Echo Bay is planning to develop its Aquarius gold property, located mainly within the eastern municipal boundary limits of the City of Timmins, in northeastern Ontario (Figure 1). The property is the site of the formerly active Aquarius Mine, which was a small 300 tonne/day underground gold mine that operated from 1984 to 1989. Recent exploration efforts, consisting of 103,000 m of surface diamond drilling, have identified an ore resource of 12,700,000 tonnes, grading approximately 2.54 grams of gold per tonne. Engineering studies have determined that the only feasible method of mining the ore body is to develop an open pit. The 12.7 million tonne ore resource will support a 7,500 tonnes/day mining and milling operation that would be carried out over an approximate 5 year period.

The proposed open pit is positioned adjacent to the western flank of the Frederick House Esker, within a zone of deep (60 - 80 m) overburden, and would extend to a maximum overall depth of 160 - 170 m below grade (Figure 2). The esker system is host to a prominent regional aquifer; hence, the management of groundwater in the vicinity of the open pit is a critical Project planning component. To provide the required groundwater control, a freeze wall cutoff barrier will be created around the perimeter of the open pit, in order to separate the mine workings from the adjacent aquifer. The freeze wall will be developed using a series of approximately 2,200 freeze pipes to completely encircle the 3,500 m pit perimeter. The freeze pipes connect with two refrigeration plants, which will supply -20°C brine to the freeze pipes, within a closed circuit system.

Open pit development is expected to generate approximately 55 million tonnes of overburden and 18.9 million tonnes of waste rock. This material will be stored in a designated overburden/waste rock stockpile area adjacent to the west side of the open pit. Both the ore and waste rock are strongly calcareous, and extremely low in associated sulphides, and as a result have no potential to generate acid mine drainage conditions. The ore is also low in associated heavy metals.

Figure 1: Project Location

Figure 2: General Site Plan

Ore processing will take place within a mill facility located just south of the proposed open pit. Milling will consist of gravity concentration, to recover coarse free gold, followed by conventional cyanide leach of the gravity tailings, and carbon-in-pulp recovery of the remaining gold. The mill effluent, containing cyanide and minor associated heavy metals, will be treated within the mill using the INCO-SO₂/AIR process, to destroy cyanide and to precipitate heavy metals. The treated mill slurry will then be discharged to a tailings containment basin for the retention of tailings solids. The basin will be constructed within the existing valley of South Crooked Creek. The tailings facility will provide sufficient retention time for final effluent polishing, such that the final effluent discharge to the environment will meet Ontario Ministry of the Environment (MOE) (formerly the Ontario Ministry of Environment and Energy - MOEE) regulatory standards. Approximately 95% of the mill water requirement will come from reclaim from the tailings basin, with the excess water (i.e., final effluent) being discharged to Crooked Creek, upstream of Moose Lake.

Infrastructure facilities associated with the Project will include: the mill building, maintenance and warehouse facilities, a mine dry, a small office complex, a 4 km mine access road, open pit dewatering wells, tailings and water lines, a 9 km 115 kV powerline, a fuel depot, an on-site non-hazardous waste landfill, two refrigeration plants, and site drainage works. Site drainage controls will include both source control, and catchments. Site monitoring will be performed to evaluate freeze wall performance, surface and groundwater quality, air and noise emissions, and site area biological communities.

As part of Project planning requirements, a detailed Closure Plan has been prepared, as per Ontario Ministry of Northern Development and Mines (MNDM) requirements. The Closure Plan will return the site to a "natural or near natural" condition, following the completion of mining activities. This will include the removal of all surface equipment, machinery and infrastructure, as well as general site area restoration. Restoration will include the development of a new pit lake, with an associated productive fishery, and will provide for revegetation of all disturbed areas, including the overburden/waste rock stockpile and the tailings basin. Restoration of the tailings basin will include restoration of the South Crooked Creek drainage and habitats within the basin. In addition to meeting the requirements of MNDM, the Closure Plan also provides for aquatic and terrestrial habitat restoration, in accordance with the agreed upon requirements of the federal Department of Fisheries and Oceans (DFO) and the Ontario Ministry of Natural Resources (MNR). Financial assurances to cover the cost of closure are required as part of the closure plan process.

Finally, in developing site plans for the Project, and as a consequence of carrying out the Canadian Environmental Assessment Act (CEAA) process, provisions have been made for various fish habitat compensation measures, in accordance with requirements of Section 35(2) of the federal Fisheries Act.

The schedule for Project construction includes three phases: a preparatory development phase, the free wall start-up phase, and the main construction phase. The preparatory construction phase was undertaken in 1997 and consisted of:

• freeze wall preparatory work (i.e., construction of the pit perimeter access road, clearing the open pit area, drilling and casing of the freeze wells, manifold/header installations, and freeze plant construction); and,
• completion of the powerline.

Phase two, freeze wall start-up is scheduled to begin during the first quarter, 2000, concurrent with detailed design engineering. Efficiencies are realized by starting the freeze wall operation in the winter, when the ground is already frozen. Demonstration of free wall success is also considered desirable to support project financing.

The remainder of the construction (i.e., the main construction phase) will require approximately 16 months to complete. The main construction phase is scheduled to begin in April 2001, to support commencement of production in 2002.

1.2 Regulatory And Planning Context

The regulatory and planning process for the Project includes consideration of federal, provincial and municipal requirements. Federal involvement is focused on requirements of the Fisheries Act and CEAA. To the extent that DFO has determined that Project development will result in the harmful alteration, disruption or destruction of fish habitat, an Environmental Assessment (EA) is required under provisions of CEAA. Furthermore, as the Project production rate will exceed 600 tonnes/day, the EA must be carried out at the Comprehensive Study level of investigation, as determined by theComprehensive Study List Regulations.

At the provincial level, a number of permits are required, pursuant to the Ontario Water Resources Act, theOntario Environmental Protect Act, the Lakes and Rivers Improvement Act, and the Planning Act. Of particular note in this regard, are permits required for: open pit dewatering, tailings basin construction, mill wastewater treatment, site clearing, road and powerline construction, landfill development, and air and noise emissions.

At the municipal level, conformity with zoning provisions and official plans of the City of Timmins and the Corporation of the Township of Black River-Matheson are required.

Application of government regulatory and planning requirements also includes provision for various regulations, guidelines and standards. The majority of these requirements are exercised at the provincial level, but there is significant involvement of the federal and municipal levels of government, as well. Representatives of all three levels of government have been involved in the review of the Aquarius Project EA, and have harmonized their requirements, through the coordinating efforts of DFO. DFO is the Responsible Authority for ensuring that the provisions ofCEAA are carried out.

1.3 Scope Of The Environmental Assessment

The scope of the EA includes all aspects of: mining, ore processing, tailings solids and wastewater management, and site infrastructure development. The EA also applies to the construction, operation and eventual decommissioning of Project components. Within this context, and in recognition of the involvement of the various levels of government, theEA is focused most strongly on those Project aspects which affect, or have the potential to affect, the hydrological environment. This includes consideration of surface and groundwater hydrology and aquatic habitat. Study focus on the hydrological environment reflects provisions of the Fisheries Act in triggering theEA, and the role of DFO as the Responsible Authority.

Beyond the general provisions of CEAA, the nature and extent of materials to be included in the EA were determined through extensive agency and public consultation. This consultation involved input from several federal and provincial regulatory agencies, as well as that provided by local residents, the general public, and the First Nations.

1.4 General Setting

The majority of Project development lands fall within the municipal limits of the City of Timmins (the City). However, portions of the tailings containment facility also fall within the adjacent boundaries of the Corporation of the Township of Black River-Matheson (TBRM), to the east. Timmins is a community of 47,461 persons (1991 census), and has a strong mining history. Forestry operations also provide an important resource base for the local economy. There are currently six active mines within the City limits, five of which are gold mines. The City Official Plan (OP) recognizes mining as the cornerstone of the local economy, and actively supports the responsible development of new mining ventures within City lands. The majority of City lands are forested and are designated as wilderness within the OP; mining is permitted within this designation. Timmins is also a provincial government administrative centre, with representation of several ministries, including MNDM,MOE,MNR, and the Ministry of Labour (MOL). TBRM is essentially a rural municipality, which contains a number of small population centres, the largest of which is the town of Matheson, with a population of 984 (1991 census).

Local residents within the Project area are thinly distributed along the Highway 101 corridor, just north of the mine site, and along Highway 67, which connects (from the north) to Highway 101. These residences are all rural in character. There are also a number of small cottage developments, more remote from the Project site. Kettle Lakes Provincial Park is located approximately 2 km north of the proposed Project development area. The park is classified as a Recreational Park, and provides a mix of natural environment preservation and recreation functions.

Northern portions of the District of Timmins, in the vicinity of the Project, generally exhibit a gently rolling to flat terrain developed on poorly drained, deep varved clays and clay tills. The Frederick House Esker, east of Night Hawk Lake, provides local relief in the Project site area, interrupting an otherwise flat clay plain landscape. Numerous, small kettle lakes and depressions are associated with the esker, including several lakes within Kettle Lakes Provincial Park.

Regional drainage is provided by Night Hawk Lake, and by the Whitefish, Frederick House, and Driftwood Rivers. Night Hawk Lake, just west of the Project site, discharges north to the Frederick House River. The Driftwood River drains areas to the east, in the vicinity of Moose Lake, and flows northeast to the Black and Abitibi Rivers. Local drainage of the Project site area is provided mainly by Crooked Creek, which drains to Moose Lake and has a surface watershed area of 55 km². Three smaller watersheds, focused on Aquarius, Roundelay, and McGoshen Lakes, drain west to Night Hawk Lake. Drainage within local watersheds is controlled to a large extent by the relationship of these watersheds to the Frederick House Esker.

Forest community development is controlled by drainage and soil conditions, and by logging and fire events. Local forest communities on the esker are dominated by jack pine, with minor associations of poplar, black spruce, white birch, and balsam fir. The flanks of the esker support transitional communities dominated by black spruce, poplar, white birch, and balsam fir. Clay plain areas are dominated by spruce and fir forests, including areas of forested muskeg.

Local wildlife and fisheries communities are typical of those which inhibit boreal regions. Moose are the dominant ungulate species. Other wildlife species include black bear, wolves, and a variety of furbearers and small mammals. Bird life is characterized by a moderately diverse avian community during the breeding and migratory periods, and by a sparse community during the winter. The density and diversity of wildlife species increases with increasing structural complexity of forested habitats.

From a fisheries perspective, the Project site is located within the Frederick House River Unit, which hosts the most productive sport fishery in the region. This is primarily due to the presence of both Night Hawk Lake and Frederick House Lake. These large warmwater lakes were created and/or expanded by the installation of the Ontario Hydro control dam. Only a small percentage of the lakes and watercourses found in the District provide coldwater habitat, most of which are associated with esker systems and areas of glacial outwash. Within the general Project area, numerous kettle lakes and small creeks support a diversity of warm and coldwater fish species. These species include brook trout, northern pike, perch, and lake whitefish.

2.0 PROJECT DESCRIPTION

2.1 Mining

Mining operations will consist of: site preparation, freeze wall installation and formation, open pit dewatering, overburden removal and disposal, and ore and waste rock mining. Associated activities include noise and dust control, wastewater management and disposal, and monitoring.

The proposed open pit is centred on the former underground Aquarius Mine, and includes within its perimeter, the headframe and mill building, tailings storage facilities, and yard areas associated with that operation. These facilities occupy approximately 20% of the open pit footprint, and will have to be removed during site preparation. Tree cover has already been removed from the pit area, as part of site preparation activities. Existing mine buildings and related facilities are scheduled to be sold, for reuse elsewhere. Bulk and other non-hazardous materials, which cannot be sold or reused, will be removed for disposal to the overburden stockpile.

In order to prevent groundwater from entering the open pit, and to minimize environmental impacts, a frozen earth cutoff barrier (freeze wall), approximately 5 m thick, will be developed around the entire 3,500 m pit perimeter. The barrier will extend through approximately 60 - 80 m of overburden, and into the underlying bedrock, and will consist of approximately 2,200 freeze pipes, positioned at spacings of from 1 - 3 m. The freeze pipes connect with a series of header pipes and manifolds to two refrigeration stations. These stations will supply -20°C brine solution to the freeze pipes, within a closed circuit system. Once the system is switched on, it will take an estimated 20 - 25 weeks to complete the freezing process. Integrity of the freeze wall will be continuously monitored through a series of temperature and groundwater level sensors. Once the freeze wall has been developed, and confirmed by monitoring, active dewatering of the overburden inside the open pit will commence, using a series of moderate and large diameter pumping wells. Complete dewatering of the overburden down to bedrock will take an estimated two years.

Shortly after dewatering commences, and when the water table within the pit overburden is lowered sufficiently, overburden removal can commence. Overburden will be stripped from the pit area using conventional large tonnage mining equipment (i.e., excavators, loaders, and haul trucks). Material will be trucked to the overburden/waste rock stockpile west of the open pit area for permanent storage. The stockpile covers a footprint of approximately 250 ha, and will be developed in lifts to an approximate maximum elevation of 30 m, with 4:1 horizontal to vertical side slopes. Heavy equipment operating on the surface of the stockpile will constitute the single most prominent noise source from Project operations. Accordingly, a 10 m high working noise berm will be maintained around the northern perimeter of the stockpile, to provide noise shielding. Other noise control measures that will be employed are distance setbacks during the night hours, and possibly the use of specially fitted mufflers and engine skirts. Noise modelling studies by HGC have shown thatMOEguidelines will be met through the combined application of these measures. Dust suppression will be achieved through a combination of water spraying and surfactant use.

Ore and waste rock will be mined using conventional drilling and blasting. Ore will be hauled to the mill site, where a stockpile will be maintained to provide constant mill feed. Waste rock will be hauled to the overburden/waste rock stockpile, as per the above. To facilitate final reclamation and revegetation, waste rock will be co-mingled with overburden consisting of clays, silts, and sands.

Water from the initial two year overburden dewatering phase, will consist of clean well water, and will be discharged directly to surface water, with appropriate precautions to control erosion. Precipitation and seepage water which drains to the interior of the excavated pit, will contain suspended solids, residual ammonia from use of blasting agents, and residual oil and grease from heavy equipment use. This water will be collected separately in pit sumps for initial removal of sediment and oil and grease. Initially, treated pit sump water will be discharged to a dry kettle for exfiltration of the water and containment of the solids. Once the tailings facility is commissioned, sump water will be pumped to the tailings pond for final clarification, before being discharged to the environment.

Monitoring requirements associated with mining, and all other Project aspects, are described in Section 8 of this summary.

2.2 Ore Processing And Wastewater Treatment

Ore processing will take place at an average rate of approximately 7,500 tonnes/day, within an enclosed mill building, to be located just south of the open pit. Processing will include conventional gold milling circuitries consisting of:

• crushing and grinding;
• gravity separation for the recovery of larger free gold particles (estimated gold recovery 50%);
• cyanide leaching of the gravity tailings, to dissolve remaining gold;
• activated carbon-in-pulp (CIP) adsorption, to recover gold from the cyanide solution;
• carbon stripping and electrowinning to recover gold from the loaded carbon; and,
• in-plant treatment of the CIP tailings slurry, using the INCO-SO₂/AIR cyanide destruction and heavy metal precipitation process.

Use of in-plant cyanide destruction and heavy metal precipitation, for the treatment of mill wastes, prior to discharge to tailings, is considered by the MOE to represent Best Available Technology Economically Achievable (BATEA), for the gold industry. Test work conducted by Lakefield Research has indicated that use of this technology will produce a favourable effluent, which is very low in both cyanide and associated heavy metals. Production of such a favourable effluent is facilitated by the fact that the ore contains very low levels of associated heavy metals, compared with that of many gold mines.

Approximately 95% of mill water requirements will be derived from tailings water reclaim. The remaining 5% of water requirements will be supplied from water contained within the ore feed, and from minor gland water. All mill reagents will be stored within, or adjacent to, the mill building, with suitable facilities to contain any spills.

2.3 Tailings Solids And Wastewater Treatment

Treated mill effluent will be discharged as a slurry (i.e., tailings) to a tailings containment facility, located approximately 3 km southeast of the mill site. Tailings solids have the consistency of silt and fine sand. The tailings facility will also receive sump water from the open pit, as per Section 2.1, above.

The tailings containment facility consists of a natural valley, positioned on the eastern flank of the esker. The valley will be impounded along its eastern margin by a single, engineered, low permeability earthen dam. Tailings slurry will be delivered to the tailings basin, using a 300 mm diameter, high density polyethylene (HDPE) tailings line. Mill reclaim water from the tailings basin will be transported back to the mill using a 250 mm HDPE water line.

The function of the tailings facility is to contain the tailings solids, and to provide sufficient pond area to allow finer tailings particles to settle out from the water column, including residual heavy metals associated with these particles. In addition, the tailings pond allows for the volatilization of residual cyanide and ammonia from the system. Ammonia is derived from use of ammonium nitrate fuel oil (ANFO) blasting agents, contained within pit sump water, as well as ammonia derived from cyanide breakdown.

To ensure that sufficient pond area is available for efficient water quality treatment, the tailings pond surface area will not be less than 50 ha. This represents an average effluent retention time of approximately 50 days. Also, to minimize the potential for effluent short-circuiting, the tailings pond will be divided into two separate sections, using either a splitter dyke, or a silt curtain. A separate polishing pond of approximately 10 ha will also be constructed, immediately downstream of the tailings pond, for added clarification, prior to final effluent discharge to the environment. Test work and mass balance calculations indicate that Ontario Regulation 560/94 effluent standards will be met for all parameters, in the final discharge to the environment.

Final discharge from the tailings facility will pass through a small wetland complex, before entering the receiving water (i.e., Crooked Creek). Crooked Creek, in turn, drains to Moose Lake. Water quality calculations show that Provincial Water Quality Objectives (PWQO) for the Protection of Aquatic Life, are expected to be met in Crooked Creek, for all parameters, and under all flow conditions, including the 7Q20 condition, with the exception of copper. Calculations show that total copper concentrations will range from approximately 0.010 - 0.018 mg/L. This compares with a PWQO value for copper of 0.005 mg/L. The 0.005 mg/L value assumes that 100% of the copper is present in its most toxic form (i.e., the Cu²⁺ion). Considerations of water hardness and naturally occurring organic acids, in the receiving water, indicate that only about 10% of the copper will occur in this toxic form, which is biologically available. The remaining 90% of the copper will occur in complexed forms, which have limited biological availability. As a result, it is expected that effluent discharge to Crooked Creek will not adversely affect the aquatic biota of the creek.

2.4 Infrastructure

Project infrastructure facilities will consist of: the mill building, out buildings (i.e., maintenance and warehouse facilities, a mine dry, and a small office complex), open pit dewatering wells, tailings and waterlines, a 4 km mine access road, a 9 km 115 kV powerline, a fuel depot, an on-site non-hazardous landfill, the two refrigeration plants, and site drainage works.

The entire mill complex, including out buildings, yard areas, and parking facilities will occupy an area of approximately 6 - 7 ha. Of this area, approximately 10,000 m² (or 15%) will be occupied by buildings and tank areas.

Open pit dewatering wells will connect with a discharge line, that will direct clear well water mainly to Roundelay Lake, over a period of about two years. Secondary pumping of well water may be directed to Aquarius, Legare, or Vader's Lakes. Tailings and water reclaim lines will extend in a more or less direct route, from the mill site, to the tailings basin. Catchment basins and associated ditching will be developed along the route, as a precautionary measure for spill containment.

The proposed mine access road connects with the intersection of Highways 101 and 67, to the immediate northwest of the property. From this point, the road alignment follows around the west and south perimeters of the overburden/waste rock stockpile, to the mill site. The powerline route connects with the existing, regional 115 kV grid, north of Charland Lake and west of Highway 67, approximately 6.8 km north northwest of the mill site. From this point, the powerline route extends southward, parallelling Highway 67, at a distance of about 500 m, to the intersection of Highways 101 and 67. South of Highway 101, the powerline route follows the mine access route, around the perimeter of the overburden/waste rock stockpile, to the mill.

The non-hazardous landfill will be developed in an upland, well drained clay environment, to the southwest of the mill site. The landfill will be operated as a conventional trench/area fill system, with progressive rehabilitation.

The two refrigeration plants are located adjacent to the northeast and south sides of the open pit.

2.5 Abandonment And Decommissioning

Primary administrative responsibility for Project abandonment and site decommissioning rests with the Ontario Ministry of Northern Development and Mines (MNDM). Under provisions of the Ontario Mining Act, the proponent of a new mining operation is required to prepare a detailed mine closure plan, prior to Project development. The object of the closure plan is ultimately to return the site to a natural, or near natural condition, following the completion of mining activities, thereby rendering the site suitable for other uses, in accordance with the concept of sustainable development. Financial assurances must also be provided by the proponent to ensure that sufficient funds are available to carry out the closure plan. Closure planning provides for three levels of closure: temporary suspension, wherein the site is placed in a condition of care and maintenance, with supervision; state-of-inactivity, wherein there is an expectation of resumed operation, but there is no site supervision; and final closure (i.e., decommissioning and abandonment).

Principal measures proposed for final decommissioning and abandonment are the following:

• removal of all buildings, equipment, machinery and materials (other than overburden, waste rock and tailings) from the site, for reuse, scrap, or disposal; those non-hazardous waste items which cannot be disposed of in this manner will be disposed of in an on-site landfill, to be developed within the overburden/waste rock stockpile;
• restoration of the open pit, to create a new pit lake, that would be integrated with Legare Lake, in such a manner so as to provide productive habitat for fish and other aquatic life;
• contouring and revegetation of the overburden/waste rock stockpile, to provide restored terrestrial habitat;
• restoration of the tailings basin, including revegetation of the tailings surface, and the restoration of creek habitat for fish and other aquatic life; and,
• general site area restoration.

Restoration activities would be accompanied by development of a suitable monitoring program, to ensure that restoration measures are effective.

2.6 Labour Force And Service Requirements

During the construction phase of the Project, the construction labour force is expected to peak at approximately 424 personnel. The majority of construction personnel will be involved in the construction of the mill and crushing facilities, and the tailings facility. Once construction is complete, a total of 194 personnel will be employed on the Project. The main divisions of the operation will include: safety, administration, mill operations, mining operations, and environment. The largest divisions will be the mill staff of 60 personnel, and 100 contract mining personnel.

In addition to direct employment opportunities, development and operation of the Aquarius Project will also generate indirect and spin-off employment benefits. Statistics Canada Input-Output Division (1990 database) estimates that 0.97 indirect jobs are created for every direct job in the gold mining industry. Indirect jobs are those involving the "upstream" supply of goods and services, such as equipment purchases, supplies, contractor services, engineering, etc. Additional spin-off benefits resulting from the re-spending of wages and business income in the general economy are not included in the 0.97 figure.

More comprehensive indirect and spin-off employment data are available from Energy and Mines Resources Canada, for Northern Ontario metal mines (1988 survey). This survey indicated a total of 31,000 direct mining jobs, 116,068 indirect mining jobs, and 204,920 mining service jobs, together with additional jobs outside the region. These indirect and service jobs are not entirely dependant on the mining industry, but mining is a major factor in their continued existence. The Mining Association of Canada (1993) estimated that 3 indirect jobs are derived from each direct mining job.

The local area of Timmins is well positioned to take advantage of employment and service opportunities offered by the Aquarius Project. The area is mature with respect to the mining industry, with much of the needed suppliers and contract services already established. In addition, the local labour force is experienced in mining.

3.0 PROJECT ALTERNATIVES AND ALTERNATIVE MEANS OF CARRYING OUT THE PROJECT

Project alternatives and alternative means of carrying out the Project were evaluated through consideration of a set of "performance objectives" and associated "evaluation criteria". Performance objectives are meaningful attributes which are essential for Project success, and they provide a basis for distinguishing between the alternatives. Different sets of performance objectives were developed for the different Project components (e.g., mining, mill processing, tailings disposal, etc.). For each individual performance objective, a set of three evaluation criteria were developed. Criteria were categorized as "preferred", "acceptable' and "unacceptable".

In carrying out the evaluation of alternatives for each Project component, each alternative was evaluated according to the assigned performance objectives and evaluation criteria. If an alternative was evaluated as being "unacceptable" for one or more performance objectives, then the alternative was considered to be seriously deficient in at least one important aspect, and was therefore rejected from further consideration. Within this limitation, typically, but not always, the alternative receiving the greatest number of preferred ratings was considered the best overall alternative. However, it needs to be recognized that all performance objectives are not of equal importance, and that in some instances an alternative might be scored as the preferred overall alternative, irrespective of the balance of preferred and acceptable ratings. A system of this type was chosen, over numerical systems, because of its ease of use and inherent flexibility to accommodate the many differing aspects of the evaluations.

3.1 Project Alternatives

Project alternatives considered in the evaluation were the following:

1. mine and mill the ore on site;
2. mine the ore on site, but process the ore elsewhere;
3. mine the ore on site, and partially process the ore on site (i.e., derive a gravity or flotation concentrate), but complete the ore processing (i.e., cyanidation) elsewhere; and,
4. discontinue operations (i.e., do nothing).

Performance objectives used in the evaluation of Project alternatives included consideration of: return on investment, employee health and safety, resident health and safety, natural environment impact, socio-economic environment impact, socio-economic benefits, and amenability to rehabilitation. Mining and processing the ore on site (i.e., Alternative 1) was the selected overall preferred alternative, achieving preferred category ratings for five of the seven performance objectives, and acceptable ratings for the remaining two objectives. Alternatives 2 and 4 were rejected as being unacceptable for return on investment. Alternative 4 was also rejected as being unacceptable for the objective of socio-economic benefits. Alternative 3 was considered acceptable in overall performance, but was not the preferred choice, because it involved increased costs but derived no additional benefit under any of the objectives.

3.2 Mining

Alternatives relating to mining operations involved consideration of a number of subcomponents, each with its own set of alternatives, performance objectives, and criteria. Subcomponents and alternatives considered in the evaluations follow, with the alternatives to each mine related sub-component shown in brackets.

• mining method (shaft, ramp, open pit);
• groundwater control (freeze wall, grout curtain, conventional dewatering);
• overburden and waste rock removal and disposal (west of open pit, southeast of open pit, combination of west and southeast alternatives);
• mine water management and disposal - well water(direct water discharge to Roundelay Lake, Legare Lake, Aquarius Creek, or to Night Hawk Lake); and,
• mine water management and disposal - pit sump water (construct a separate sump water treatment system, or pump sump water to tailings).

With respect to mining method, the only economically feasible method to mine the ore body is by open pit. Underground mining methods are unacceptable for performance objectives relating to: ability to mine the ore body effectively, and cost effective operation.

Among the alternatives for groundwater control, grouting was considered unacceptable for the performance objective of: system integrity and liability. Conventional dewatering was tentatively considered as being acceptable, in overall terms, but would have a decidedly greater impact to local kettle lakes, and would also be more expensive compared with the freeze wall alternative. The freeze wall alternative would not impact the surrounding water table and associated local area lakes, and is the most cost effective alternative, and was therefore considered the preferred overall alternative.

Among the alternatives for overburden and waste rock disposal, the location directly west of the open pit was chosen as the preferred overall alternative on the basis of performance objectives relating to: cost effective operation, minimizing impacts to terrestrial and aquatic ecosystems, and aesthetics and amenability to rehabilitation. The southeast storage location was preferred from the perspective of noise control. However, noise modelling studies show that noise criteria will be met at the west overburden area. The combination alternative was preferred for all categories accept cost effective operation, and is retained as a contingency, in the event that noise mitigation measures at the west overburden area fail to perform as expected.

Mine water management includes two separate operations: well water discharge during initial dewatering, and pit sump water disposal. The latter operation will continue throughout the Project mine life. Regarding well water disposal, the preferred alternative is to direct the major portion of this water to Roundelay Lake. Roundelay Lake is the closest receiver with the capacity to handle the expected volume of water without expectation of erosion related impacts. Minor water volumes may also be discharged to other area surface water bodies. Well water quality is not an issue. The preferred alternative for pit sump water management is to pump this water to tailings, as the tailings system requires construction in any event, and will have the capacity to handle the expected volume and quality of the water. During, early sump dewatering, a separate (dry kettle) disposal option is recommended, as the tailings basin will not be ready to receive pit sump water at this time. Pit water which is directed to the dry kettle would exfiltrate to groundwater, and would not contain ammonia from use of blasting agents, as rock mining will not have commenced during early sump dewatering.

3.3 Ore Processing And Wastewater Treatment

Four alternatives were considered for ore processing. These were:

• gravity concentration;
• gravity concentration, with cyanidation of the gravity tailings;
• gravity concentration followed by flotation and cyanidation;
• direct whole ore cyanidation; and,
• flotation followed by cyanidation of the flotation concentrate.

Two performance objectives were used in evaluating the alternatives, namely: cost effective operation and process amenability to effective wastewater treatment. Since effective wastewater treatment options are available for all alternatives, the only real consideration was cost effective operation. From this perspective, the preferred alternative is gravity concentration followed by cyanidation of the gravity tailings. This alternative provides the highest gold recovery, estimated at 98.2%.

The remaining consideration is wastewater treatment. In order to provide the best available overall effluent treatment, and to guard against any adverse impacts related to possible tailings basin seepage, or tailings line upsets, a Project decision was made to utilize in-plant treatment for cyanide destruction and heavy metal precipitation. Review of the available operating technologies for gold mills shows the following available in-plant technologies:

• the INCO-SO₂/AIR treatment process;
• the hydrogen peroxide (H₂O₂)process;
• the alkaline chlorination process; and,
• the acidification-volatilization-regeneration (AVR) process.

Of these technologies, the INCO-SO₂/AIR process is the only process which has been demonstrated to be consistently effective for the destruction of free and metallo-complexed cyanides, and for precipitating heavy metals, in slurry. The INCO-SO₂/AIR process is therefore the selected alternative.

3.4 Tailings Containment And Wastewater Management

A preliminary evaluation of 11 potential tailings sites was undertaken, to determine those sites which were suitable for further consideration. This process identified four potential sites for further consideration, referred to as Sites A, C, E, and J. Performance objectives used in the evaluation of the four sites included:

• system integrity and reliability;
• cost effective construction/operation;
• compatibility with other Project components;
• minimize impacts to local aquatic habitat;
• provide optimal water quality treatment;
• minimize impacts to terrestrial environments;
• minimize impacts to the socio-economic environment;
• land availability (i.e., ownership);
• erosion control during construction; and,
• amenability to rehabilitation.

Tailings Site C (i.e., the South Crooked Creek valley site) was the overall preferred site, based on: extensive natural containment, promoting both short and long-term system integrity and cost efficient development; and, the ability to provide optimal tailings pond configurations for effective water quality treatment.

Tailings Site A was considered unacceptable because development costs would be excessive; the tailings location partially conflicts with the preferred location for the overburden /waste rock stockpile; and, tailings basin development would result in the permanent loss of Aquarius Lake. Tailings Site E was rejected because of concerns related to: short and long-term system integrity and reliability; extensive construction requirements within the Crooked Creek floodplain; potential concerns relating to rehabilitation; and, considerations relating to water quality because of limited pond size and potentials for effluent short-circuiting. Tailings Site J was rejected on the basis of: costs; poor potential for water quality treatment; and land availability.

3.5 Infrastructure

Infrastructure alternatives are, to a large extent, governed by the placement of major site facilities, most notably the open pit, tailings and overburden/waste rock stockpile areas; and by off-site linkages for powerline and road access. As a result, limited evaluations of the alternatives were performed, with the exception of those relating to the mine access road and powerline routings.

Infrastructure facilities of note include the mill building complex, the mine access road, the powerline route, and the on-site landfill. The mill site location was selected on the basis of proximity to the open pit, and the availability of near surface bedrock to provide solid foundation conditions. Only one such suitable area is available, and this is an area just south of the open pit. This site is well removed from adjacent residences, and poses no particular environmental concerns. A suitable landfill site was also found to the southwest of the open pit, at a location which meets all MOE siting criteria, and which poses no socio-economic or natural environment concerns.

Mine access road alternatives included:

• extension of the existing site access road;
• construction of a new road off Highway 101, west of the open pit area; and,
• entering the property from the east, by way of, or near, Gibson Lake Road.

Access road connection to the Highway 101/67 intersection, west of the open pit, was considered the preferred alignment choice in terms of both highway safety and avoiding potential interference with other users. The proposed route would tie into an existing intersection where motorists are already accustomed to merging traffic. Extension of the existing mine access road was rejected for safety reasons, because use of this route would require traffic to and from the mill site to cross the ore haul route. This is considered unsafe practice within the industry. Use of the Gibson Lake Road alternative was rejected because of potential interference with existing Gibson Lake Road traffic, and because development of a second road entrance, off Highway 101, in close proximity to the Gibson Lake Road entrance is considered an unsafe practice by the Ministry of Transport (MTO).

South of Highway 101, all powerline routes follow the mine access road corridor. Therefore, the alternative route locations are limited to that portion of the route north of Highway 101. Three powerline routing alternatives were considered. These included:

• a route parallel to the back lots of Highway 67;
• a route directly along Highway 67; and,
• a direct cross-country route.

Alternate power sources such as over-building a 21 km section of the existing low voltage (27.6 kV) line along Highway 101, and using generators were also considered, but were rejected at an earlier stage.

All routes are similar in distance (i.e., approximately 8 - 9 km), and provide connection to the regional 115 kV transmission line, at its closest point to the Project. The selected route is the one parallel to the back lots of Highway 67. This route was selected following open house meetings and one-on-one discussions with local residents. A direct route along Highway 67 was rejected on the basis of unnecessary visual intrusion. Direct cross-country routing was rejected because of poor ground (i.e., muskeg/swamp) conditions.

3.6 Decommissioning And Abandonment

Decommissioning and abandonment alternatives were considered in relation to the open pit and the tailings. Reclamation of other site facilities is straight forward, essentially involving facility removal and site restoration to a revegetated condition. Alternatives for restoration of the open pit area included:

• filling in the open pit workings with stockpiled overburden and waste rock, at the end of mining operations; and,
• creating a productive pit lake.

Performance objectives for open pit restoration alternatives included: cost effective operation, and natural environment restoration/enhancement. Creating a productive pit lake was selected as the best alternative from both perspectives.

Alternatives for tailings basin rehabilitation included:

• re-slurrying the tailings back to the open pit; and,
• rehabilitating the tailings in-place.

Performance objectives were the same as those described above, for open pit rehabilitation. Re-slurrying the tailings was considered unacceptable on the basis of cost. Restoration of the natural environment (i.e., creek system) could be achieved with either alternative. Rehabilitating the tailings basin, in-place, was therefore the preferred alternative.

4.0 AGENCY AND PUBLIC CONSULTATION

Agency and public consultation are central to theEA process, in both defining the scope and focus of the study, and in ensuring that the concerns and interests of all the participants are properly addressed.

4.1 Government Agency Consultation

Government involvement in the Project encompassed input from the following federal, provincial and municipal agencies:

Federal Agencies

• Canadian Environmental Assessment Agency (CEAA);
• Department of Fisheries and Oceans (DFO);
• Environment Canada (DOE); and,
• Natural Resources Canada (NRCan).

Provincial Agencies

• Ontario Ministry of the Environment (MOE), (formerly the Ontario Ministry of Environment and Energy - MOEE);
• Ontario Ministry of Natural Resources (MNR);
• Ontario Ministry of Northern Development and Mines (MNDM); and,
• Ontario Ministry of Transportation (MTO).

Municipal Agencies

• City of Timmins; and,
• Corporation of the Township of Black River-Matheson.

Various meetings and discussions have been held with the above agencies, in connection with the Project, and various materials have been made available to them for their review and comment. Of particular note are the following documents:

• Environmental Prospectus Focusing on Aquatic Environment Effects, Aquarius Project - AGRA, December 1996;
• Environmental Baseline Study, Aquarius Project, Timmins, Ontario - AGRA, February 1997;
• Draft Comprehensive Study Environmental Assessment, Aquarius Project, Timmins, Ontario - AGRA, March 1997;
• Mine Closure Plan, Aquarius Project, Timmins, Ontario -AGRA, July 1997; and,
• various technical documents (i.e., companion documents) and other supporting materials addressing: hydrogeology, geotechnical considerations, plant engineering, freeze wall engineering, tailings dam construction, powerline routing, and noise mitigation.

The CEAA process was officially triggered on December 23, 1996, with a letter toAGRA fromDFO, responding to the December, 1996 Environmental Prospectus. A Project scoping meeting was subsequently held with the federal and provincial agencies on January 24, 1997, to confirm the overall scope and focus of the EA document, and to discuss mechanisms for general public involvement.

Within the capacity of their respective review mandates, each agency has been free to review any and all aspects of the Project. However, within this general structure, each agency also has a specific mandate, which provides a focus to their involvement.CEAA has primary responsibility for ensuring that all process requirements of theCanadian Environmental Assessment Act are properly carried out. DFO is the Responsible Authority for the Project, and has overall responsibility for ensuring that the EA is fully and properly carried out. It is also the role of DFO to coordinate the responses of the other government agencies. DOE and NRCan have responsibilities to provided technical input, on various Project aspects.

The provincial agencies also have specific mandates, per the following: MOE - water and air quality management; MNR - administration of crown lands and protection of natural resources; and,MNDM - administration of mineral resources and site decommissioning, following the completion of mining activities. Municipal governments are responsible for planning and zoning related issues, general community servicing and for ensuring orderly economic development.

Each of the above agencies provided written comment on the Draft Comprehensive Study Environmental Assessment (CS-EA), and where appropriate, was provided with a written response from Echo Bay, and/or its consultants, to each of their comments. Amendments were made to the final CSR document, to reflect agency comments and responses. Agency comments were very broad in their coverage of the Project, as would be expected; but in general, the majority of comments focused on: freeze wall development and maintenance for groundwater control; tailings site selection; surface water quality and management; air and noise emissions; protection of Kettle Lakes Provincial Park; fish habitat compensation requirements; site reclamation following mine closure; and, monitoring.

4.2 Local Residents And Land Users

As indicated in Sections 1.4 and 5.4, of this summary, there are a small number of local residents within the general Project vicinity. The majority of these are located at widely spaced intervals along Highways 101 and 67, and at more remote cottage developments centred on Charland and McInnis Lakes, approximately 6 km north of the Project site, and at Gibson Lake, approximately 10 km southeast of the Project site. In addition to local residents, there are also a number of land users in the general Project vicinity, which participate in a variety of resource and recreational pursuits.

Local residents and land users were invited to participate in the pre-draft CS-EAFebruary 13, 1997 open house presentations in Timmins, and in the post-draft CS-EA May 8, 1997 open house sessions in Timmins, and the May 9, 1997 open house in Connaught. The Draft CS-EA and the Environmental Baseline Study were made available to local residents at three public locations, prior to the May 1997 open house sessions. Additional meetings were held on February 12, June 3, June 25, August 14 and August 22, 1997, to discuss specific Project aspects with local residents and land users. As well, Echo Bay held one-on-one discussions with a number of local residents and land users, to address their specific concerns, and received written comments from selected individuals. Written responses were provided by Echo Bay, and/or its consultants, to the written comments. In some instances, discussions with local residents lead to the purchase of selected properties. Compensation arrangements were also developed with selected area land users, where there was clear evidence that mine development would adversely affect their livelihoods.

Throughout the process of local resident and land user consultation, Echo Bay made concerted efforts to address the legitimate concerns of those involved. However, as with any project of this magnitude, it is not always possible to satisfy the concerns or interests of all the involved parties. This was particularly true in the case of concerns expressed by Mr. Roger Fortier, a local resident, and those of Ms. Corinne Miller, who acted in support of Mr. Fortier's interests. Mr. Fortier's concerns dealt with: property values, road and powerline routing, location of the overburden/waste rock stockpile, groundwater concerns, noise and dust considerations, and employment opportunities. Technical aspects relating to all of these issues are covered in depth within the CSR. Representations were made by Mr. Fortier, and/or persons acting on his behalf, to Echo Bay, to the federal and provincial ministries, the City of Timmins, and to federal and provincial area politicians. These representations included requests for a separate provincialEA designation for the Project, which would essentially duplicate the federalCEAA process, as well as a request for an Ontario Municipal Board Hearing which was held in Timmins on January 14 and 15, 1998. Mr. Fortier's concerns are dealt with at some length in Sections 6 and 7 of theCSR.

In the final analysis, Mr. Fortier's concerns, as expressed by Ms. Miller, at a meeting with the Hon. Gilles Bisson, provincial MPP for Cochrane South, focused on the locations of both the overburden/waste rock stockpile and the mine access road connection to Highway 101 (letter from Hon. Gilles Bisson to Echo Bay, dated August 26, 1997). Echo Bay considered this final request and has determined that relocation of the mine access road to the location suggested by Ms. Miller would be inappropriate (see Section 3.5 of this summary), and that partial relocation of the overburden/waste rock stockpile is unnecessary from an impact standpoint, and would place a substantial added financial burden of approximately $3.0 million (U.S.) on the Project.

Echo Bay is of the opinion that the legitimate concerns of local residents and land users have been suitably addressed through theCEAA process, and through related permits issued by MNR, and that Project operation will conform with all applicable government regulatory requirements.

4.3 First Nations

The Aquarius Project lies within the Traditional territories of the Matachewan First Nation, which is represented by the Wabun Tribal Council. Echo Bay involved the Wabun Tribal Council in Project discussions, commencing in February, 1997. No Project related concerns were expressed by the Council, other than that the Council should be kept informed of Project developments and that the requirements of CEAA should be met.

4.4 General Public

Commencing in January 1997, and prior to the first (February 1997) open house sessions, a series of articles appeared in the local newspapers, informing people of the Aquarius Project. In addition, open house sessions were held, as per the above, to invite general public participation in the planning for the Project. The February 13, 1997 open house sessions were held from 2:00 pm - 5:30 pm, and from 7:00 pm - 10:30 pm, and were well attended, with a total sign-in of 146 persons for the combined sessions. The open house presentation consisted of an overhead seated presentation of about 45 minutes, followed by a poster session. Several Echo Bay representatives were on hand to answer questions. The May 8 and 9, 1997 sessions were similar to the February sessions, except that there was no formal overhead presentation. The total number of sign-in attendees for the May open house sessions was 91 persons; however, it was noted that several persons did not sign-in at the Connaught open house. A listing of open house poster materials is provided in Section 7.5 of the CSRdocument.

The response of the general public to the Project was supportive, and was consistent with Project expectations, given the prominence of mining in the local area. The majority of discussions at the open house presentations focused on: general interest, questions on Project related technologies, particularly the freeze wall application, environmental protection measures, and employment and service opportunities. Detailed lists of general public questions on the Project are included in Sections 7.3 and 7.5 of the CSRdocument.

In addition to general representations to the public, separate presentations were also made to the Timmins Local Citizens Committee (LCC) on February 12, July 17 and September 10, 1997. The LCC is a local citizens group that was established under the direction of MNR, pursuant to Section 23 of the Crown Forest Sustainability Act (1994), for the expressed purpose of providing input into the preparation and implementation of forest management plans, and any other matters referred to the committee by the Minister of Natural Resources. TheLCC provides representation of the following local interest groups:

• tourist outfitters;
• campers;
• forestry operators;
• First Nations;
• the Mattagami Region Conservation Authority;
• naturalists;
• anglers and hunters;
• cottage owners;
• mining industry operators; and,
• the general public.

The LCCexpressed interests in: surface water systems and aquatic habitat; freeze wall development and groundwater control; wastewater treatment and management; wildlife, hunting and fishing; noise and dust control; tailings facility selection, construction and operation; and site reclamation. The LCC was supportive of the Project, but expressed reservations concerning the Site C tailings location, suggesting that an upland site (i.e., Site J) would be preferable to many of its members, as such a site would have less impact on terrestrial and aquatic habitat. However, rather than provide a specific recommendation in this regard, theLCCacknowledged the more substantive decision making powers of the regulatory agencies in this matter, recognizing that wildlife and fisheries habitat concerns comprised only one aspect of the overall tailings site evaluation process (see Section 3.4 of this summary for further discussions on tailings site selection).

5.0 EXISTING ENVIRONMENT AND VALUED ECOSYSTEM COMPONENTS (VECs)

A detailed Environmental Baseline Study has been completed for the Aquarius Project, under separate cover (AGRA 1997a). Information provided in this document highlights aspects from the baseline study which are key to the Environmental Assessment.

The baseline study adopts an ecosystem approach, integrating ecosystem structure and function. The study addresses all relevant aspects of the physical, chemical, biological and socio-economic environment, but is focused most strongly on those aspects which are most likely to be affected by Project development, i.e., surface water and groundwater hydrology, water quality, fisheries and aquatic resources, and local area land uses. Less attention was directed to the terrestrial environment, which has been extensively disturbed by ongoing forestry operations, and to a lesser extent by past mining activities.

5.1 Physical Environment

The Frederick House Esker runs north-south through the Project area, and provides hydraulic continuity between area surface and groundwater resources. Surface waters associated with the esker include several small kettle lakes and creek headwaters, including several lakes within Kettle Lakes Provincial Park. In contrast, lands east and west of the Frederick House Esker are founded on broad clay plains. Clay soils provide an effective barrier against groundwater/surface water interactions in these areas.

Prominent groundwater discharge areas occur in the vicinity of Legare and Vader's Lakes, and at the headwaters to South Crooked Creek. Esker lakes at the south end of Kettle Lakes Provincial Park, as well as Lake #2 and Deep Lake, east of the Project site, are associated with groundwater recharge zones, rather than discharge zones. These recharge lakes are founded on sandy terrain and lack surface water outlets. Long, Round, and June Lakes, to the south of the Project area, also lack surface water outlets, but their chemistry suggests that these lakes both receive and transmit groundwater.

Local groundwater sources, associated with the Frederick House esker, are essential to the maintenance of aquatic ecosystem function throughout the greater portion of the Project study area. This includes resident well use, flood control and recreational opportunities. A significant Project induced change to the groundwater regime would have the potential to alter both the configuration of surface waters and their associated aquatic ecosystems, and uses.

Finally, chemical analysis from 25 surface water lake and creek stations showed that Project area waters are generally of high quality, with most parameters meeting Provincial Water Quality Objectives (PWQO) for both the Protection of Aquatic Life and for Drinking Water. Where exceedances of PWQO standards occur, the exceedences are generally small and typical of regional background conditions. It is important to maintain these water quality conditions. Sediment quality was also determined for lake and creek sites.

5.2 Aquatic Environment And Wetlands

Aquatic resource investigations were focused on habitat descriptions, benthos and fish communities. Investigations included both lake and creek systems. Most of the site area lakes are small kettle lakes, associated with the esker, which range in size from 2 - 40 ha. Most of these lakes are moderately deep. Bottom substrates range from sand to clay, depending on lake position relative to the esker. Extensive organic deposits occur on the bottom of some lakes.

Both cold and warmwater fisheries are present in the Project area. Coldwater fisheries, characterized by the presence of brook trout (most often stocked), are restricted to two principal areas. These are: (1) groundwater discharge zones associated with Vader's Lake, and portions of Crooked Creek and North Tributary Creek immediately downstream of Legare and Vader's Lakes; and (2) to isolated, internal drainage lakes, notably Deep, Round and June Lakes, as well as most of the lakes in southern Kettle Lakes Provincial Park. Other local area lakes support pike populations, most frequently with perch, and less frequently with white sucker and lake whitefish. Walleye are restricted in their local distributions to Night Hawk and Moose Lakes.

Benthic communities vary with substrate type and are typical of communities normally associated with esker and clay plain habitats of the Timmins area. Sensitive species groups such as mayflies and caddisflies are well represented in appropriate habitats.

The most significant impact from open pit development will be the physical displacement of local creek habitats contained within the pit perimeter, notably Crooked Creek Sections CC-2 and CC-3, upstream of Legare Lake. Construction of the tailings facility in the valley of South Crooked Creek will temporarily displace approximately 10,500 m² of aquatic habitat.

Crooked Creek upstream of Legare Lake lacks significant groundwater inflow, and is considered a warmwater system. Creek Section CC-2 is a comparatively small creek section with an average width of only 0.3 m and a length of 350 m. The creek in this area is characterized mainly by silt/muck substrates, with some boulders and clay, and by creek bank vegetation consisting mainly of alders with a lesser graminoid component. Section CC-3, immediately downstream of CC-2, is much broader, averaging 9.5 m in width, and is 550 m in length. Substrates in this creek section consist entirely of muck and silt, and creek bank vegetation is dominated by graminoid species, with some alder. The dramatically increased width of this creek section, compared with that of CC-2, is the result of beaver impoundments and the backwater effects of Legare Lake. Creek Sections CC-2 and CC-3 support a fish community of finescale dace, northern redbelly dace, fathead minnows, and brook stickleback. It is also suspected that northern pike and yellow perch, from Legare Lake, are likely to spawn in the creek mouth area.

South Crooked Creek receives a substantial portion of its flow contribution from groundwater, and is therefore considered a coldwater system. Such systems are valued because of their potential to support a coldwater (i.e., brook trout) fishery. However, due to the small size of this system (i.e., creek widths of approximately 3 m), and the presence of numerous beaver dams which fragment the habitat, South Crooked Creek does not appear to support a coldwater fishery. The only fish species noted during electroshocking surveys by AGRA was brook stickleback. This species is common in cold and warmwater lake and creek habitats throughout the region.

Project area wetlands are concentrated primarily along the margins of lakes and creeks, with minor occurrence of isolated wetlands in topographic depressions. An evaluation of Project area wetlands was carried out, according to MNR protocols, and none of the wetlands, or wetland complexes, were found to be Provincially Significant.

5.3 Terrestrial Environment

Forest communities of the esker system, as mentioned, have been extensively altered as a result of forestry operations. In the predevelopment condition, most areas of exposed esker sands were dominated by jack pine, and/or by mixed jack pine communities. Most cutover areas on the esker have been replanted to jack pine. Clay plain forests are dominated by black spruce, balsam fir, tamarack and white cedar. Transitional zones between the esker and the clay plain are typically characterized by poplar and poplar/birch communities, and associated conifers.

Based on available habitat structure, information obtained fromMNR files (including those of Kettle Lakes Provincial Park), and site investigations by AGRA, wildlife species present in the Project area are considered to be typical of those which inhabit the region. Within this context, the density and diversity of wildlife species is expected to be greatest within more structurally diverse habitats, such as those provided by riparian and mixed forest zones. The only notable wildlife areas that have been identified by MNR, in the immediate Project vicinity, are moose aquatic feeding areas associated with: (1) the margins of Roundelay and Tincan Lakes, and their downstream drainages; (2) wetlands bordering Legare Lake and its immediate downstream drainages; and (3) downstream margins of Crooked Creek, below its confluence with South Crooked Creek.

Also of potential interest are migratory bird species, largely because of the federal mandate to protect such populations, and the associated participation of Environment Canada in theCEAA process. Five notable bird species were observed in the Project vicinity during mid-July surveys. These included one provincially significant species (i.e., the black tern), and four regionally significant species (i.e., the double-crested cormorant, the wood duck, the brown trasher and the eastern wood-pewee). The black tern, double-crested cormorant, and the wood duck are all associated with aquatic habitats that would not be disturbed by Project development. The remaining two species are at, or near, the northern limits of their respective ranges, where they have expanded into disturbed forest habitats. Both species are common further south, and are only considered regionally significant because of their comparatively recent expansion into the area.

5.4 Socio-economic Environment

Socio-economic considerations are focused on Kettle Lakes Provincial Park, and on area residents and land users. This excludes consideration of employment and service opportunities related to mine construction and production, which are dealt with in Section 2.6 of this summary.

Kettle Lakes Provincial Park occupies an area of 1,261 ha, of which approximately 450 ha is contained within the Crooked Creek watershed, at the south end of the park. There are six small to medium sized lakes in this southern portion of the park, the largest of which is 9.3 ha. All of these kettle lakes exhibit internal drainage, with direct connection to the groundwater table, such that there are no inflow or outflow creeks. As such, lake levels within the park are controlled by groundwater levels. Nearly all of the park area is forested with jack pine.

The park offers day and overnight recreational opportunities, which include: tent and trailer camping, swimming, canoeing, fishing, hiking, picnic and playground areas, and interpretive programs. There are currently 165 campsites, of which 83 have electrical outlets. Drinking water and toilet facilities are available, with drinking water being taken from wells. The park does not provide serviced facilities or supervision for winter use, but it is open to snowmobilers and cross-country skiers who use the Park on their own recognizance.

Aside from Kettle Lakes Provincial Park, local residents and land users are restricted to: scattered residents and commercial establishments along Highways 101 and 67; a single property on the north side of Vader's Lake which has been acquired by Echo bay; two seasonal residents on Long Lake; a cluster of cottage owners to the north, at Charland and McInnis Lakes; a second cluster of cottage owners to the south of Project area watersheds on Gibson Lake; short-term (one year) licensed forestry operators; and other mineral exploration companies. There are no permanent or seasonal residents on the east shore of Night Hawk Lake, opposite the Aquarius Property; and there is only one seasonal resident on the west shore of Moose Lake. In addition, there are a few hunting/trapping cabins in the area. One local resident (Mr. Roger Fortier) has an unlicenced, bare soil, ultra-light airstrip in the back portion of his residential property, northwest of the proposed overburden/waste rock stockpile.

In addition to site-specific land users, the general area is used by anglers, hunters and trappers.

There are no specific First Nations' interests in the proposed Project development area, and there are no known, or suspected, archaeological sites within the vicinity of Project development areas.

5.5 Sensitivities

Principal environmental sensitivities requiring consideration in Project planning are the following:

• the local groundwater regime has the potential to be impacted by developments associated with the open pit and the tailings areas;
• surface waters have the potential to be impacted as a result of: direct habitat loss, changes to groundwater and surface water flow regimes, general site runoff, and wastewater discharges;
• fisheries and aquatic resources have the potential to be impacted through habitat loss, changes in groundwater and surface water flow regimes, and effluent discharge;
• wetlands have the potential to be impacted by direct displacement and through changes to the groundwater table;
• terrestrial habitats have the potential to be impacted through direct displacement of habitats, water level changes and general disturbance;
• Kettle Lakes Provincial Park has the potential to be impacted through noise and dust emissions, and through changes to groundwater levels, which could affect park lake levels; and,
• local residents and land users have the potential to be impacted by general disturbances such as noise and dust, impacts to the groundwater table, and direct loss of habitats and or the quality of habitats suitable for resource harvesting, including forestry, fish, and wildlife.

Sensitivity to impact does not imply that impacts will occur, but only that they could occur, depending on the nature of the development, and the mitigating measures employed to eliminate, or lessen, the potential for impacts.

A key consideration in the assessment of sensitivities is that involving ecosystem functional relationships and linkages. The most obvious linkage is that involving groundwater, surface water, and fisheries/aquatic resources. Other linkage sets include those between: groundwater, surface water and wetlands; groundwater resources and Kettle Lakes Provincial Park; and, groundwater resources and forest growth. Continued stable groundwater conditions and site area water quality are central to the maintenance of these linkages, and their associated ecosystem functions.

6.0 SUMMARY OF PRINCIPAL CONCERNS, RISKS, MITIGATING MEASURES AND CONTINGENCIES

6.1 Predicted Environmental Impacts and Mitigating Measures

Predicted environmental effects (impacts) are those effects which would occur in the absence of mitigation. Mitigation is employed to eliminate, or otherwise reduce, predicted environmental effects to acceptable (i.e., non-significant) levels. Environmental impacts remaining after mitigation are referred to as residual effects, and are dealt with in Section 7 of this summary. Mitigating measures are of three basic types. These are:

• engineering and/or management practices designed to prevent the impact from occurring in the first place;
• remedial measures to correct, or lessen, an impact once it has occurred; and,
• remedial measures designed to off-set an impact, through other measures, once it has occurred.

The latter category would include such aspects as fish habitat compensation, and site restoration following the completion of mining.

The following discussions summarize predicted, or potential, environmental effects and proposed mitigating measures that will be employed to protect VECs:

Groundwater:

• potential adverse impacts which would otherwise occur to the local aquifer, as a result of open pit mining, will be prevented through use of the freeze wall, which will provide a complete surface to bedrock cut-off barrier to groundwater flow;
• minor groundwater mounding (predicted at <2 m above the baseline condition) is expected to occur adjacent to the west perimeter of the freeze wall, and will be relieved through ditching;
• a predicted average reduction of 330 m³/day in groundwater flow to Crooked Creek headwaters will occur as a result of recharge losses and flow impediment caused by open pit/freeze wall development - this amounts to approximately 1 - 2% of the annual average creek flow in this portion of the creek - mitigation is not proposed;
• minor groundwater mounding (predicted at <4 m above the baseline condition) is expected to occur adjacent to the downstream face of the tailings dam - groundwater mounding in this area will be relieved through ditching;
• potential impacts to groundwater quality, which might otherwise occur, as a result of tailings effluent seepage or spills, will be prevented by treating the mill effluent before it leaves the mill;
• potential impacts to groundwater quality, which might otherwise occur, as a result of fuel or reagent spills, will be controlled through the use of containment facilities and emergency response procedures; and,
• following mine closure, a potential long-term (20 - 100 years) reduction in the local groundwater table of up to 3.6 m adjacent to the pit area, which might otherwise occur if the final pit lake level is set at the current water level of Legare Lake, will be prevented by raising the water level of the pit lake, or the pit lake and Legare Lake in combination, to negate the potential drawdown effect.

Surface Water:

• a predicted 1 - 2% reduction in flows within the upper section of Crooked Creek is expected to occur, as per the above - mitigation is not proposed;
• possible minor erosion to Tincan Creek could potentially occur as a result of added well water discharge to Roundelay Lake, during initial open pit dewatering - impacts are not expected and contingencies are available to reduce or redistribute flows;
• a negligible increase in suspended solids loadings to Night Hawk and Legare Lakes could potentially occur in association with site runoff - erosion controls will be put in place to minimize erosion to an acceptable level, also the large size of the Night Hawk Lake watershed (i.e., 2,400 km²), which would receive the greatest volume of runoff, precludes meaningful potential for impact;
• potential adverse impacts to tailings effluent receiving waters (i.e., downstream Crooked Creek and Moose Lake) will be prevented through use of in-plant SO₂/AIR treatment of the mill effluent (prior to discharge to tailings), and through extended effluent aging in the tailings pond, as well as through maximum tailings basin water recycle;
• potential adverse impacts to Night Hawk Lake, which could otherwise occur as a result of excessive water draw during the filling of the open pit, on closure, will be relieved through seasonal regulation of the water withdrawal rate; and,
• following mine closure, a potential long-term (20 - 100 years) reduction in the water levels of local closed system kettle lakes (of up to 0.8 m), as well as changes (increases/decreases) in local creek flows (by up to 15%), which might otherwise occur if the final pit lake level is set at the current water level of Legare Lake, will be prevented by raising the water level of the pit lake, or the pit lake and Legare Lake in combination, as per the above (surface water impacts would be driven by changes to the groundwater regime).

Aquatic Habitat:

• permanent loss of 5,300 m² of warmwater creek habitat from the headwaters of Crooked Creek, upstream of Legare Lake, as a result of open pit development - mitigation will be provided through fish habitat compensation - this creek section supports four species of "minnows" and likely provides localized spawning habitat for Legare Lake pike and perch;
• temporary loss of 10,500 m² of coldwater creek habitat from South Crooked Creek, as a result of tailings basin development - mitigation will be provided through fish habitat compensation, and through creek habitat restoration following mine closure - South Crooked Creek supports at least one species of "minnow";
• permanent loss of 3,000 m² of warmwater creek habitat from Aquarius Creek, as a result of overburden/waste rock stockpile development - mitigation will be provided through fish habitat compensation - this creek section supports northern redbelly and finescale dace; and,
• following mine closure, potential long-term (20 - 100 years) reductions in fish habitat that would be associated with groundwater induced changes to surface water systems, as per the above - mitigation would involve increasing the water level of the pit lake, or the pit lake and Legare Lake in combination, as per the above.

Fish habitat compensation that will be provided in connection with the above losses, will include both short and long-term mitigation. Short-term mitigation will include:

• the restoration and enhancement of brook trout spawning areas at the north end of Vader's Lake, including the creation of approximately 1,000 m² of new spawning habitat; and,
• the likely creation of self-sustaining brook trout habitat associated with Deep, #2 and Low Lakes, east of the Gibson Lake Road. The degree of success of this mitigation is dependent upon confirmation of in-situ hydrogeologic conditions.

In addition to these short-term compensation measures, which were developed pursuant to Fisheries Act requirements, Echo Bay has also agreed to:

• provide annual funding ($10,700/year for 7 years) to the Timmins District MNR, to assist with walleye population and recruitment surveys of Moose Lake;
• provide $2,000/year, during the period of mine life, to the Timmins Fur Council, to support local, ongoing fish stocking programs; and,
• introduce walleye fingerlings to Harriet and Janet Lakes, west of Timmins, as an adjunct to walleye fingerling transfers to Legare Lake - this is provided that economies of scale are such that these additional introductions to Harriet and Janet Lakes can be achieved at nominal cost, and that walleye fingerlings are available for such purposes.

Long-term fish habitat compensation measures will include:

• restoration of the open pit, to create a productive pit lake that would be connected directly to Legare Lake, to form a pit lake/Legare Lake complex - the complex would support all those fish species found within Legare Lake (i.e., northern pike, yellow perch, lake whitefish, white sucker, brook stickleback, northern redbelly dace, finescale dace and Iowa darter), as well as walleye, which would be introduced to the system, as fingerlings, on an annual basis during the period of mine operation - habitat creation would include approximately 75,000 m² of littoral zone habitat (i.e., within the 0 - 5 m depth zone), and 700,000 m² of pelagic habitat;
• development of 1,300 m² of creek habitat, to provide a new drainage connection between Aquarius Lake and the new pit lake; and,
• restoration of approximately 10,500 m² of creek habitat within the tailings basin area, including establishing a coldwater fishery (i.e., brook trout) within the new creek habitat. A coldwater fishery does not currently exist in South Crooked Creek, primarily due to the limited size of the creek and habitat fragmentation by beaver dams. These inherent characteristics may also limit the degree of success in establishing a coldwater fishery after tailings restoration.

Wetlands:

• an estimated displacement of 29 ha of wetland habitat, which would be replaced with an estimated 25 - 35 ha of wetland habitat, as part of mine site restoration - wetlands that would be lost are widespread and commonplace in the region, and have no special significance.

Terrestrial Habitat:

• temporary displacement of an estimated 640 ha of terrestrial habitat, that will occur from site development, approximately 90% of which is associated with the overburden/waste rock stockpile and tailings areas. Much of the area that would be displaced has already been disturbed through recent logging operations; all habitat will be restored on closure of the mine site, and major tree clearing will be avoided during the nesting and rearing season (i.e., from May 15 - July 31);
• an estimated permanent displacement of 80 ha of terrestrial habitat, for open pit development, most of which was previously disturbed by mining and forestry operations. This habitat would be rehabilitated as lake habitat, as per the above; and,
• potential minor disturbance to wildlife as a result of general site area activity.

Kettle Lakes Provincial Park:

• potential increase in noise levels, associated with mining activities, particularly heavy equipment operation on top of the overburden/waste rock stockpile - mitigation will be provided through the combined use of working noise berms; setbacks; and source reduction measures, such as specialized mufflers and engine skirts; as required, to meet MOErequirements;
• potential increase in dust emissions, largely as a result of heavy equipment operation - mitigation will involve the use of water spray and surfactants; and,
• following mine closure, potential long-term (20 - 100 years) reductions in park kettle lake levels, of up to 0.8 m - mitigation would be implemented, as per the above, to prevent such impacts.

Local Residents and Land Users:

• potential increases in noise and dust levels - there are approximately 10 households within about 1 km of the mine site; mitigation measures would be as per the above;
• potential impacts to property values during the period of mine operation - active intervention in the market place, by Echo Bay, has thus far contributed to an increase in local property values, and there is no present expectation that property values will decrease because of the presence of the mine, therefore, additional mitigation is not currently proposed
• potential reduction in the livelihoods of commercial trappers and outfitters using Project area lands - mitigation has involved negotiated financial settlements (to be finalized), with the value of settlements being based on documentation provided by the affected individuals.

6.2 Principal Agency And Public Concerns

As indicated in Section 4.1, government agency comments on the Draft CS-EA were very broad in their coverage and context. A majority of the comments were tabled in the context of requesting further details and/or clarification of existing information, and the need to provide updated information concerning public and agency consultation, and Project design changes. A detailed listing of government agency comments is provided in Section 7.1 of the main document.

Beyond these generalities, the majority of concerns and comments, as per Section 4.1 of this summary, focused on: freeze wall development and maintenance for groundwater control; tailings site selection; surface water quality and management; air and noise emissions; protection of Kettle Lakes Provincial Park values; the provision of fish habitat compensation; site reclamation following mine closure, including the potential for changes to groundwater and surface water regimes; and, monitoring.

Echo Bay representatives have responded to all of the concerns and comments expressed, as per this document and Companion Document K, and believe that all agency concerns have been appropriately addressed and/or resolved. The greatest efforts in responding to agency comments involved: (1) further evaluations of the tailings alternatives, in order to present a clearer and more detailed rational for the selection of the preferred tailings site (i.e., Site C); (2) the provision of greater detail on the design considerations of freeze wall formation and maintenance, particularly those aspects involving possible modes of failure, and contingencies to prevent such failures; and (3) the maintenance of groundwater and surface water regimes, and associated fish habitats, following mine closure.

Public concerns, including those of local residents and land users, were also very broad in their context. General public comments are detailed in Section 7.5.2 of the main document. Those of individual residents and local land users are detailed in Section 7.3 of the document, together with summary responses; and, those of the Timmins LCC are presented in Sections 6.2.6 and 7.5.3. The vast majority of comments and concerns from the general public were matters of clarification, largely because very few members of the public were able to take the time, or had the technical background, to throughly review the documentation. Many concerns were also expressed on the basis of rumours and similarly ill founded information. Finally, a number of concerns were expressed out of self interest, legitimate and otherwise. In all cases, Echo Bay representatives went to considerable efforts to address the concerns, irrespective of their basis.

The main concerns of the general public and local residents and land users can be broadly summarized as follows:

• integrity of the freeze wall, including responsibility on the part of Echo Bay for any damages that might be caused to adjacent properties, in the event of a freeze wall failure (water wells are the central issue here) - mechanisms of freeze wall failure and remedial actions are documented in the report, and Echo Bay has readily acknowledged its need to make appropriate restitution in the event of adverse impacts to adjacent properties resulting from its actions;
• potential impacts of tailings effluent discharge on lower sections of Crooked Creek and on Moose Lake - this consideration has been thoroughly addressed in the document and has had considerable outside review by the agencies and third party reviewers appointed by the agencies - no such adverse impacts are expected;
• ensuring that noise and dust are appropriately controlled, such that the potential for adverse effects to property enjoyment, by local residents and provincial park users, is adequately addressed - mitigation measures to control noise and dust are proposed, along with the development of a liaison committee to address any concerns that might arise;
• potential adverse impacts to property values - as per the above, the actions of Echo Bay have thus far enhanced local property values, and based on the predicted ability to mitigate noise impacts from the Project, negative impacts on property values during the life of the mine are not anticipated;
• location of the powerline - separate public consultation was held on this aspect, and a route was selected which does not impinge on the interests of the local residents - where easements across private properties were required, these were obtained through co-operative negotiation with the individual land owners;
• location of the mine access road connection with Highway 101 - the selected intersection at the junction of Highways 101 and 67 is considered to be the safest and most suitable alternative;
• location of the tailings area - this aspect was addressed at length in connection with concerns raised by MNR, and is documented within Section 5.3 of the main document, with additional materials presented in Companion Document K (submissions to MNR); and,
• location of the overburden/waste rock stockpile in relation to Mr. Fortier's unlicensed ultra-light airstrip - the concerns of Mr. Fortier have been thoroughly investigated, and according to guidelines provided by the Aerodrome Safety branch, of Transport Canada Aviation, proposed site facilities do not compromise the safe operation of the airstrip.

In addition, a few members of the public expressed that Echo Bay did not provide ample opportunity for public input and consultation. The data presented in Sections 6 and 7 of the document would suggest otherwise.

6.3  Project Risks, Uncertainties And Contingencies

The principal Project risks and uncertainties are those related to:

• possible freeze wall failure;
• possible tailings dam failure;
• wastewater treatment system malfunction;
• ineffective noise control;
• maintenance of groundwater and surface water regimes following mine closure; and,
• ineffective fish habitat restoration.

The following discussions address the risks, uncertainties, and contingencies associated with the above Project components. However, the fact of their discussion does not mean that the events, or scenarios, described are likely to occur. To the contrary, every effort is being made to prevent the occurrence of the described events, to the extent that Echo Bay has no expectation that the following malfunctions will occur.

Freeze wall Failure:

The risk and possible mode(s) of freeze wall failure are addressed at length in the document, and in the response to NRCan in Companion Document K. In order to describe the most plausible scenario for a potential failure of the freeze wall, it is helpful to first define the phases of freeze wall development, dewatering and overburden removal.

The initial freezing process begins in Phase I with the commencement of brine refrigeration and circulation. Monitoring during this phase will include brine temperature, and groundwater temperature monitoring to detect potential areas of incomplete freeze wall formation, which would be indicated as temperature differentials. Piezometers will also be used during this phase to collect detailed data on natural groundwater fluctuations inside and outside of the freeze wall. Phase I will be complete when monitoring data indicate that the wall is completely formed, from surface into bedrock, to its design thickness of 3 - 5 m.

After verification of freeze wall formation, based on the monitoring data, dewatering inside the pit will begin (Phase II). Dewatering will be accompanied by continued monitoring of groundwater elevations inside and outside of the pit wall, and by monitoring of brine and groundwater temperatures. Excavation of overburden will begin in this phase, proceeding progressively with dewatering, as the water table inside of the freeze wall is lowered through the overburden and down to the bedrock.

Phase III represents completion of groundwater drawdown and excavation of overburden down to the bedrock. At this point, the frozen barrier will be subjected to the maximum imbalance force. Even under this maximum unbalanced condition, the summation of forces shows a structurally sound barrier, with a 3.5 factor of safety.

For purposes of evaluating potential failure scenarios, a "failure" of the freeze wall is considered to be any opening which allows groundwater movement from the exterior of the wall to the interior. Openings in the wall could result from incomplete freezing in localized zones of higher groundwater velocity, which are more difficult to freeze.

The most likely period for a breach in the wall to occur is during Phase II. This is because dewatering will introduce a hydraulic gradient into the system which would increase groundwater flow through any openings in the wall. However, if this were to occur, the increased groundwater flows would be detected as a temperature differential by the groundwater and brine temperature monitors. Therefore, if wall formation was not complete and not detected after Phase I, it would be detected by monitoring data during Phase II. Once detected, remedial measures are available to close the opening, by grouting the affected area and/or installing additional freeze pipes and allowing additional freeze time. These remedial measures would be repeated, as necessary, until such time as a complete groundwater barrier is achieved.

In terms of environmental impacts, it is important to note that dewatering must precede excavation. Therefore, a breach at a given elevation in the wall would be identified and corrected prior to significant excavation of the overburden below the level of the breach. As such, a "spontaneous" failure event, wherein the freeze wall fails without warning, will not occur. It is also important to note that a groundwater flow rate of 12,300 m³/day through the freeze wall would be required to affect a 1 m drawdown in the water table outside of the wall. It is simply not possible for this rate of groundwater flow through an opening in the wall to go undetected and uncorrected.

The second mode of freeze wall failure that is possible, at least theoretically, is a failure later in the Project life, once the internal pit area has been fully dewatered and mining is well underway. As discussed above, such a late term failure would not occur without early warning signs which would be detected by the monitoring system. Therefore, such a failure would result only if early warning signs of potential problems were ignored and dewatering and excavation were permitted to continue without remedial measures. Clearly, it is not Echo Bay's intent to allow such a sequence of events to progress unattended; and, in fact, it would not be possible, as a practical matter, to continue mining with significant groundwater inflow to the pit.

However, in order to fully identify and evaluate the risks associated with the Project, and available contingencies, a late term failure scenario must be considered as a possibility. In terms of environmental impacts, the worst time for such an event to occur would be near the end of operations, when the excavation is at its maximum extent. If an uncontrolled failure was to occur at this stage, there would be a substantial drawdown in the local water table that could affect water levels in local wells and lakes, extending into Kettle Lakes Provincial Park. If immediate measures to control such a breach (i.e., grouting, additional freeze wells) proved unsuccessful, then the extreme response in such an event would be to abandon the mine and flood the pit, as per the proposed closure plan. A pipeline could be in place to commence filling the pit, from Night Hawk Lake, within 3 - 4 months, and the pit would be completely filled within 18 - 24 months. Actively filling the pit will reduce the groundwater gradient, thereby reducing the rate of drawdown in the surrounding water table, and lessening the theoretically maximum drawdown impact. The model estimate of this impact, allowing for mitigation, would be a maximum drawdown in the groundwater table of approximately 50  m, immediately adjacent to the pit. Drawdown would decrease with increasing distance from the pit, such that the 1 m drawdown contour would extend a maximum distance of approximately 5 km from the pit. The estimated time frame for recovery of the groundwater table with the mitigation proposed is 4 years. Echo Bay acknowledges that it would be liable to correct any damage caused by such an event, including provision of individual water supplies, if necessary.

Tailings Dam Failure:

The risk of tailings dam failure can never be entirely discounted; however, such risks can be minimized through competent engineering and system management. If a major tailings dam failure was to occur, there would likely be an accelerated, or sudden, release of waterborne contaminants to the environment, as well as the potential for the release of tailings solids directly into Crooked Creek. The impact of such a release of materials would be tempered by the fact that: (1) the tailings effluent is treated to final effluent discharge levels within the mill, prior to discharge to the tailings basin (except for the removal of suspended solids), and (2) the tailings solids have no acid generating potential and are extremely low in associated heavy metals. The most significant impact of a major dam failure would therefore be the likely deposition of tailings solids (i.e., silt) within Crooked Creek. Depending on the severity of the siltation, it may or may not be appropriate to clean up the tailings deposits. The deposits would not pose a chemical threat, and would be unlikely to pose a meaningful long-term habitat alteration, as the creek would adjust naturally to the increased bedload.

In the event of a partial, or major, tailings dam failure, milling operations would be immediately shut down, and the dam would be repaired. Cleanup requirements would be assessed in consultation with DFO, MNR and MOE.

Wastewater Treatment System Malfunction:

A wastewater treatment system malfunction could potentially result in unacceptably high levels of contaminants (cyanide and heavy metals) in the final effluent and in the receiving water. The risks of such an event are limited and entirely controllable. In a worst case condition, the mill would be shut down until the problem is fixed. Extended retention time (i.e., >50 days) in the tailings pond would mitigate any sudden, short-term malfunctions in system performance. Therefore, the realistic potential for an impact to the environment (i.e., receiving water) from such a malfunction, could only result if the upset conditions were ignored and the mill continued to operate as usual.

Ineffective Noise Control:

Ineffective noise control could cause unacceptable disturbance to local residents and park users. However, noise control is a modulated function, whereby increasingly progressive technical and operating controls can be applied to address the concern. Noise modelling studies show that measures are available, and can be strengthened if necessary, to meet recommended MOE noise guidelines.

Maintenance of Groundwater and Surface Water Regimes:

Failure or malfunction of grade control structures at the outlet of either the pit lake, or Legare Lake, could result in a long-term (20 - 100 years) reduction of the groundwater table, and accompanying changes to surface water systems, including a reduction in local lake levels, of up to 0.8 m. The likelihood of structural failure can be minimized through competent engineering. Also, if a problem was to develop, the response time of the hydrologic regime would be very slow (years to 10's of years), thereby allowing remedial action to be implemented before the potential impacts could take effect.

Ineffective Fish Habitat Restoration:

There is little likelihood of complete failure of fish habitat compensation measures. It is more a question of the degree of success, and the period of time that is required to achieve a desired level of success. There are consequently no risks, as such. Any deficiencies in habitat performance would be detected through monitoring and will be adjusted through active intervention to improve habitat conditions. In the event that habitat success could not be achieved, then alternate habitat compensation would have to be developed in consultation with DFO andMNR.

7.0 SIGNIFICANCE OF RESIDUAL ENVIRONMENTAL IMPACTS (EFFECTS)

Residual environmental impacts (effects) are those impacts which remain after mitigation and compensation.

7.1 Physical Environment

Physical environment components of interest are groundwater and surface water. Residual effects on groundwater are restricted to:

• minor, very localized, changes to the groundwater table in the vicinity of the open pit (change of <2 m), and tailings dam areas (change of <4 m); and,
• a slight reduction (1 - 2%) in the average annual flow contribution to Crooked Creek, in the creek area just downstream of Legare Lake.

Water table increases will be mitigated through ditching, and are considered to be minor, and to a large extent entirely reversible. No significant ecological or socio-economic effects are associated with the anticipated changes. Impacts are therefore considered to be not significant.

Residual surface water effects include:

• possible minor resuspension of bottom sediments in Tincan Creek, in response to well water discharge to Roundelay lake, during the initial two year pit dewatering phase;
• possible increased suspended solids loadings to Night Hawk and Legare Lakes, as a result of site area runoff and possible well water discharge erosional effects;
• minor parameter increases in the tailings effluent receiving water (i.e., downstream Crooked Creek), particularly for copper; and,
• water withdrawal effects to Night Hawk Lake, during filling of the open pit, at the end of mining operations.

All of these impacts are considered to be minor, with no significant potential to cause significant ecological or socio-economic impact. Also, all effects are entirely reversible. Effects are therefore considered to be not significant.

7.2 Aquatic Environment

Aquatic environment effects are limited to temporary and permanent creek habitat losses, as described in Section 6.1 of this summary. These impacts will be addressed through short and long-term habitat compensation, as further described in Section 6.1, and are therefore considered to be not significant.

7.3 Terrestrial Environment

Terrestrial habitat effects are related to forest and brush clearing for facility development, and include the following residual effects:

• temporary and permanent displacement of approximately 640 ha and 80 ha of habitat respectively, much of which is already disturbed, as a result of recent forestry operations;
• possible minor disturbance to moose aquatic feeding areas along the west margin of Legare Lake;
• possible minor disturbance to two regionally significant bird species (i.e, the brown thrasher and the eastern wood-pewee), both of which are common elsewhere, are at, or near, their northern distributional limits, and are adapted to disturbed conditions; and,
• potential minor impacts to nesting birds, as a result of minor forest and/or brush clearing during the nesting and rearing period (i.e., May 15 - July 31).

Temporary terrestrial habitat losses are regrettable, but are necessary for facility development. Impacts to temporarily disturbed habitats will be restored through revegetation programs, at the end of the mine life, and are therefore considered to be reversible, and not significant. Terrestrial habitat that will be permanently lost, as a result of open pit development, will be replaced with productive lake habitat. This trade-off in habitat types is considered to represent a net benefit in overall ecosystem diversity. Impacts associated with this loss are therefore considered to be not significant. The potential for disturbance to the two regionally significant bird species is also considered to be not significant, as these species are both adapted to disturbed conditions, and have extended their ranges northward in response to disturbed forest conditions. Avoiding major tree clearing between the dates of May 15 and July 31 effectively negates any significant potential for adverse effects to nesting birds.

7.4 Socio-economic Environment

Residual socio-economic impacts are restricted to the following conditions:

• potential noise disturbance to local residents and Kettle Lakes Park users, primarily as a result of heavy equipment operation associated with overburden/waste rock stockpile operations;
• potential dust emissions that could result from heavy equipment operation, as per the above;
• potential impacts to property values as a result of the presence of the mine, and any associated disturbance; and,
• potential impacts to the harvesting success of commercial hunters and trappers, as a result of temporary habitat losses, and/or general activity related disturbance to wildlife.

The magnitude and geographic extent of noise and dust disturbance can be controlled to MOE accepted standards through application of mitigation measures, as proposed. Potential impacts in these areas are also entirely reversible. Potential adverse impacts to property values are unlikely to occur, and would be entirely preventable through the continued active intervention of Echo Bay in the local real estate market. Potential economic impacts to local commercial hunters and trappers will be off-set through financial compensation. As such, potential residual impacts to the socio-economic environment are considered to be not significant.

8.0 MONITORING

Site area monitoring requirements are complex, and will involve a number of different aspects, which are too numerous to be fully addressed in a summary of this type. Therefore, only the major monitoring commitments are discussed. It should also be understood that, in addition to monitoring items identified below, there will also be various types of regular property and system inspections to ensure that environmental performance is being maintained. This will include comprehensive monitoring for erosion control during construction. Echo Bay will also conduct regular site audits, likely on an annual basis throughout the period of mine operation.

8.1 Freeze Wall Performance

Monitoring for freeze wall performance has included, or will include, the following components:

• confirmation of freeze pipe integrity and positions, during installation;
• confirmation of refrigeration plant performance;
• freeze pipe and ground temperature monitoring; and,
• groundwater piezometer monitoring.

The position and integrity of freeze pipes is critical to freeze wall success. Each freeze pipe required individual pressure testing to confirm pipe integrity, and the position of each pipe along its entire length required testing with a gyroscope, to confirm allowable separation distances between pipes. Provision was made for 10% re-drills, for pipes where design spacing requirements were exceeded.

With regard to refrigeration plant operation, the manifold system and related pumps are designed to supply a uniform flow of coolant to each freeze pipe. To confirm operating efficiency, the temperature, pressure and flow rate of the circulating brine will be measured by an automated data acquisition system.

Temperature monitoring will consist of two separate components. The first will involve the periodic measurement of temperatures within the freeze pipes. To measure freeze pipe temperatures, brine flows to selected pipes will be temporarily shut off, such that temperature probes (thermistors) can be lowered into the pipes. Temperature readings would be taken at approximately 0.6 m intervals along the total length of the pipes. If there are areas of groundwater flow through the freeze wall, small localized temperature increases will be evident in the areas of groundwater flow. An additional, approximately 100 ground temperature monitors will also be distributed around the pit perimeter, to check for any unusual temperature conditions adjacent to the freeze wall. The majority of these sensors will be located along the east perimeter of the freeze wall, where localized areas of higher groundwater velocities are expected.

Finally, a series of approximately 100 groundwater piezometers will be installed adjacent to, and mainly outside of, the freeze wall to detect changes in groundwater levels adjacent to the freeze wall.

Information from these monitoring systems will be routinely reviewed, to identify any potential problem areas. Monitoring intensity would be most pronounced during initial freeze wall formation and dewatering operations, when problems are most likely to show up. Once the integrity of the freeze wall has been confirm, monitoring intensity would be adjusted accordingly.

8.2 Effluents And Surface Water

Effluent and surface water monitoring will include the following components:

• SO₂/AIR plant operational monitoring for pH, cyanide, and heavy metals;
• pit sump water quality monitoring for total suspended solids, ammonia, and oil and grease;
• tailings pond water quality monitoring for cyanide species, ammonia, heavy metals, and other parameters, including toxicity, as per Ontario Regulation 560/94 and the Certificate of Approval;
• site runoff water quality monitoring for pH, total suspended solids, oil and grease, and toxicity;
• site area receiving water quality monitoring for a variety of parameters, with the specific parameters being dependent on location relative to effluent and/or runoff source loadings; and,
• monitoring of all significant flows associated with the above, to determine loadings.

Surface water monitoring stations, for chemical and physical parameters will include: Legare Lake; Crooked Creek above Homestead Lake; Crooked Creek above and below the tailings effluent inflow; Moose Lake; Aquarius Creek; and Tincan Creek. Permanent flow measurement stations will be established at three locations on Crooked Creek, and at the final tailings effluent discharge. Area lake levels will continue to be monitored throughout the life of the Project.

8.3 Groundwater

Groundwater quality will be measured from approximately 10 permanent well stations positioned strategically around the property, with the foci of monitoring operations being: the tailings area, and the plant site and overburden stockpile areas. Groundwater sampling wells may or may not be used for groundwater level monitoring, as a larger network of piezometers will be installed, in relation to freeze wall monitoring, as per the above.

8.4 Fisheries And Aquatic Resources

Fisheries and aquatic resources will be monitored in association with effluent discharges (i.e., in Crooked Creek and Moose Lake); and in association with habitat compensation. Effluent impact monitoring would involve upstream and downstream sampling of fish populations, benthos and sediments. Water quality data would be available from regular, ongoing Project monitoring, as per the above. The frequency of biological monitoring remains to be determined, but would likely be carried out one year following mill start-up, and at three year intervals thereafter, until the end of active operations.

Monitoring for fish habitat compensation performance will reflect the site specific goals for each compensation measure. Depending on circumstances, this would include consideration of the following: water quality, water levels, water temperature, habitat structure, plankton, benthos and fish populations. Fisheries and aquatic resource monitoring is expected to extend beyond the Project life in the case of the pit lake and rehabilitated tailings basin drainages.

8.5 Noise And Dust

Two continuous noise level monitors will be set up in the south end of Kettle Lakes Provincial Park. These will be operated annually, from the May 24 weekend, to the Labour Day weekend in early September. In addition, two separate 24 hour, manned noise surveys will be conducted annually during this same time period, by a noise specialist, to provide detailed data on noise sources, and to help with the interpretation of continuous noise level data. Results of the annual surveys will be summarized and included in a report prepared by the noise specialist.

Noise monitoring at local residences will include the year-round maintenance of continuous noise monitors at, or adjacent to, two resident locations, and at a control station remote from the mining site, adjacent to Highway 101. In addition, twice yearly, 24 hour manned noise surveys will also be conducted at several locations in the vicinity of the mine, including areas near Highway 101, as well as in the vicinity of Night Hawk Lake, and Gibson Lake seasonal/permanent residences. These surveys will be co-ordinated with park surveys, and would be reported together.

Dust will be monitored on the property, and at selected locations, adjacent to the property, where impacts are most likely to occur. Dust would be monitored using standard dustfall collection jars.

8.6 Ongoing Government Agency Involvement

Ongoing government agency involvement in site area monitoring will include the participation of DFO, MOE,MNR,MNDM, and Ontario Parks. Federal agencies may choose to defer portions of their monitoring responsibilities, concerning CEAA, to the provincial agencies. Monitoring results will be made available to the appropriate agencies on either a predetermined basis, or on an as required basis. Monitoring data which are required by regulation, or by permits and certificates of approval, will be submitted to the appropriate agency.

8.7 Ongoing Involvement Of Local Residents And Land Users

In order to maintain an ongoing dialogue between local residents and Echo Bay, Echo Bay will identify a designate, whose role will be to listen to, and respond to, concerns that might arise. The Echo Bay designate will maintain an up-to-date file on all meetings and correspondence related to this function. Significant issues, involving the possible interest of provincial ministries, will be brought to the attention of the appropriate ministry. Finally, Echo Bay will work with the MOE to develop a liaison committee to address noise and dust related issues. It is anticipated that such a committee will include representation from Echo Bay, MOE, Kettle Lakes Provincial Park, and local residents.