1.0 Information Requests and Responses: Canadian Environmental Assessment Agency

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3 September 22, 2014 Mr. Kamran Faisal Mr. Alvin Yuen Canadian Environmental Assessment Agency Environmental Assessment Applications Unit 425, A Street 3211 Albert Street Edmonton, Alberta Regina, Saskatchewan T5J 2W2 S4S 5W6 Subject: Tazi Twé Hydroelectric Project Environmental Impact Statement Addendum II: Responses to the Canadian Environmental Assessment Agency and Saskatchewan Ministry of Environment Information Requests Pertaining to the Tazi Twé Hydroelectric Project Environmental Impact Statement (Addendum II) Saskatchewan Power Corporation (SaskPower) and the Black Lake First Nation (together, the Proponent) have received the review comments and information requests (IRs) submitted by the Canadian Environmental Assessment Agency (the Agency) and the Saskatchewan Ministry of Environment (MOE) for the Tazi Twé Hydroelectric Project (the Project). The Proponent s responses to each of IRs submitted by the Agency and MOE are provided in Sections 1.0 and 2.0, respectively; additional supporting information for the IR responses are provided in Attachments A through U of this Environmental Impact Statement (EIS) Addendum II document. 1.0 Information Requests and Responses: Canadian Environmental Assessment Agency Comment Number 1: General Environmental effects analyses should be updated in the EIS based on the responses to the [IRs]. Update the relevant environmental effects analyses in the [EIS] based on the responses to the [IRs]. Where required, environmental effects analyses have been updated based on responses to the IRs submitted by federal and provincial reviewers; these updated analyses are included in the text below and/or as Attachments to this EIS Addendum II document. Comment Number 2: EIS Guidelines, Sections 16 and The EIS Guidelines state that detailed information be provided on required management and monitoring plans. EIS Guidelines [S]ection 16 states The goal of a monitoring program is to ensure that proper measures and controls are in place and to provide clearly defined action plans and emergency response procedures to account for human and environmental health and safety. In the EIS, the [P]roponent will describe the monitoring 1

4 activities at all stages of the [P]roject, the [P]roponent s proposed commitment to implementing these activities and resources provided for this purpose. The program will need to provide the key information such as contacts, protocols, measured parameters, deadlines, intervention in case of non-compliance of legal requirements and production of monitoring reports The EIS Guidelines also state in [S]ection that The [P]roponent will then describe its environmental protection plan and environmental management system through which it will deliver this plan. The EIS cites several monitoring and management plans that required additional information to determine the effectiveness of these plans to mitigate potential adverse effects that may arise due to [P]roject activities. Provide the additional detail and proposed outlines, including any appropriate action levels, as requested in EIS Guidelines for the following plans cited in the EIS, including any associated monitoring: Environmental Protection Plan, which includes a Site Water Management Plan, a Waste Rock Management Plan, a Waste Management Plan, a hazardous materials management strategy, a Weed Plant Management Plan, an Emergency Response Plan and any other necessary management plans; Erosion and Sediment Control Plan; Construction Effects Management Plan; Decommissioning and Reclamation Plan and associated Monitoring Program; Access Management Plan; Blasting Plan; Occupational Health and Safety Plan; Water Quality Monitoring Program; [and] Turbidity Monitoring Program. The Proponent has provided outlines (annotated Tables of Contents) for the various management plans and monitoring programs referenced in the EIS; these can be found in Attachment A. The Environmental Protection Plan is considered the primary management plan for the Project; all other plans and programs are included as sub-plans or sub-programs within the scope of the Environmental Protection Plan. The Water Quality Monitoring Program and the Turbidity Monitoring Program are considered components of the Site Water Management Plan and Erosion and Sediment Control Plan, respectively. A Construction Effects Monitoring Plan was not included as part of the Environmental Protection Plan in Attachment A, or as a stand-alone plan. Rather, plans for managing and monitoring potential effects from Construction to the environment have been included in more activity- or component-specific plans (e.g., the Blasting Plan) and/or programs (e.g., the Turbidity Monitoring Program). 2

5 Comment Number 3: EIS Guidelines, Sections 16 and The EIS does not describe all the permitting instruments that will/may be required from Aboriginal Affairs and Northern Development Canada [AANDC] in relation to the proposed [P]roject. As per section 5(2) of CEAA [Canadian Environmental Assessment Act] 2012, the environmental effects associated with any power, duty or function to exercised by a federal authority must be understood. a) Identify and discuss the changes to the environment and the resulting environmental effects associated with all federal permitting instruments that will/may be required. Section 5(2) of CEAA refers to potential indirect environmental effects that may be associated with federal authorities exercising their powers, duties, or functions (including issuance of permits by AANDC). These indirect environmental effects (if they exist) would be additive to the direct environmental effects described under CEAA Section 5(1). The Proponent has evaluated the potential for the issuance of permits or other federal regulatory approval instruments to result in an environmental effect not already being assessed under CEAA Section 5(1) and does not believe that any such unconsidered environmental effects exist. Following is a description of AANDC permitting for the Project that will be required prior to Project implementation. Although permit preparation work can commence prior to approval of the EIS, CEAA Section 7 states that no federal permits, approvals, or authorizations can be issued authorizing implementation of any aspect of the Project until the EIS is approved. Almost all major components of the Project will be located within the boundaries of Chicken Indian Reserve No. 224 on lands designated for hydroelectric development under the Black Lake First Nation Reserve Land Designation Document: Hydro Electric Facility, dated November 9, This includes the powerhouse, power tunnel, tailrace, water intake structure, bridge and abutments, submerged weir, contractor work camp, waste rock disposal areas, proposed borrow areas, contractor work areas, and most of the Project access roads. Once the EIS has been approved and the final Project design locations have been confirmed, the Proponent will provide AANDC with the required land location information to proceed with development of a Headlease for the Project. According to information provided to SaskPower in a July 2, from Sonya Rudniski (AANDC) to Jennifer Sargent (SaskPower), work will also be required to develop a commercial lease precedent document prior to commencing work on developing the Headlease (Rudniski 2014, pers. comm.). Based on the Proponent s understanding of information contained in the July 2, from AANDC, most Project components would be permitted ancillary to the Headlease. Regarding permitting of the Waste Rock Disposal Areas, the Proponent believes these areas could also be permitted ancillary to the Headlease with a short term permit because it is not anticipated that any acid generating rock will be deposited in the areas based on analysis of rock materials tested during the baseline drilling program. Only one major Project component will be located on Black Lake Indian Reserve No. 224 lands outside of the designated hydroelectric development area. Approximately 3.5 kilometres (km) of the proposed access road connecting the Project area with Highway No. 905 is located on Chicken Indian Reserve No. 224 lands outside of the area designated for hydroelectric development. The Proponent understands that this portion of the access road could be authorized under an Access Road Easement and/or Permit. Although several potential access road and bridge locations were evaluated, only one access road and bridge location is proposed by the Proponent (location shown on EIS Figure 1.3-1: Tazi Twé Project Site Plan). 3

6 The Proponent acknowledges that a Transmission Line Easement will be required for the transmission line that will connect the Project with SaskPower s existing Northern Transmission Line. However, the transmission line is considered a separate project from the Tazi Twé Hydroelectric Project and will be subject to a separate Environmental Assessment review. The transmission line project would also be authorized and permitted separately from the Tazi Twé Hydroelectric Project. Comment Number 4: Fish and Fish Habitat, Section (pages and 12-49) Ice on the Fond du Lac River : The EIS states that [i]n winter, cooler ambient air temperatures and reduced riparian flow volumes resulting from Project operation could affect overwintering habitat of fish by reducing water temperatures and increasing the potential for ice formation (Stantec 2010) in the bypassed section of the Fond du Lac River, however it does not appear that there has been any analysis on current ice conditions or how those ice conditions may change under [P]roject operation. Ice formation (including formation of frazil and anchor ice), may impact a fishery in a variety of ways, including: river flow; water levels up and downstream of the ice formation; fish habitat and passage; fish health; morphological and sediment transport characteristics of rivers. a) Provide an analysis on the current ice conditions in the bypassed section (reaches 3 to 21) of the Fond du Lac River and how they may change under [P]roject operation. Provide an analysis on how predicted ice conditions under [P]roject operation in the bypassed section (reaches 3 to 21) of the Fond du Lac River may impact fish and fish habitat, including any changes to overwintering habitat predictions made in the EIS. To improve calibration of the water temperature models developed for the Fond du Lac River and confirm predictions of ice formation, temperature data was collected at four sites near Grayling Island and three sites immediately upstream of the tailrace channel outlet location throughout the winter of 2013/2014. Data loggers were removed from the river in May, 2014; a technical memorandum summarizing the temperature data and additional modeling results has been prepared. This technical memorandum can be found in Attachment B. The results of the technical memorandum were used to validate predictions of temperature changes and frazil and anchor ice formation in the river. Changes to water temperatures in the Fond du Lac River that could result from Project operation during winter (as well as in summer) are expected to be biologically insignificant (see Sections 3.1 and 3.2 in Attachment B). Winter ice conditions predicted for the period of Project operation were compared to current ice conditions on the river, where possible (Attachment C). Differences between current, baseline conditions and predicted ice conditions for the period of Project operation were evaluated to determine the potential for impacts to fish and fish habitat. The evaluation considered potential impacts to fish health (e.g., injury resulting from contact with frazil ice) and ice-induced changes to overwintering habitats, as well as the timing and duration of such impacts. Detailed results can be found in Attachment C. Comment Number 5a: Section (pages to 12-60); Appendix 12.2, Section (page 27); Appendix 12.4, Sections 5.2 and 6.0 (pages 5, 6 and 8). Entrainment and/or Impingement Exclusion Bar Racks : Section states that an exclusion bar rack will be located in front of these passages and will reduce entrainment of debris into the power tunnel. The exclusion bar rack is also intended to be a visual deterrent for 4

7 fish The panels of the exclusion bar rack will include steel bars 10 mm [millimetres] thick by 150 mm deep, with an anticipated bar spacing of 80 to 160 mm on center and a clear opening of approximately 70 to 150 mm It is anticipated that some Black Lake fish will passively drift into the vicinity of the water intake where they could be potentially impinged on the exclusion bar racks or entrained with power tunnel inflows. However, the total number of fish leaving the Black Lake fish community is not expected to change over the current level of out-migration Appendix 12.2 states that CRA [commercial, recreational or Aboriginal] fisheries will not be impacted at [Middle Lake] as a result of Project operation and changes to hydrology. There is no analysis made in the EIS to account for fish that may be attracted to the new intake flows. The EIS is lacking justification for the selection of the exclusion bar rack spacing range, including why the exclusion bar racks are only being considered as a visual deterrent for fish instead of a physical barrier to passage. The EIS lacks information to quantify expected fish entrainment, as well as the impact of impingement and turbine mortality on fish populations in Black Lake and Middle Lake. Engineering considerations related to power tunnel water intake fish screen requirements are presenting in a technical memorandum provided in Attachment D. The effectiveness of the proposed exclusion bar rack as a physical and/or visual deterrent to fish was recently assessed; a detailed description of the results is provided in the technical memorandum in Attachment E. The likelihood that fish may become impinged at the face of the exclusion bar rack is also evaluated in the assessment. The potential for fish to be attracted by the flows at the water intake channel opening is also discussed. The memo provided in Attachment E also includes a detailed assessment of turbine-induced mortality. Survival rates of turbine-passed fish were estimated based on fish size and point of contact along the turbine blade, the turbine configurations under consideration for the Project, and various operating efficiencies. The potential for impingement and entrainment of fish at the water intake in Black Lake to affect fish populations downstream in Middle Lake is evaluated in Attachment E. A second technical memorandum was developed to assess the numbers, sizes and species of fish that may be lost from Black Lake as a result of impingement or entrainment at the water intake; this memo is included in Attachment F. An assessment of potential effects to select populations of valued component (VC) fish species in Black Lake is also summarized in the memo found in Attachment F. Comment Number 5b: Section (pages to 12-60); Appendix 12.2, Section (page 27); Appendix 12.4, Sections 5.2 and 6.0 (pages 5, 6 and 8) Entrainment Pressure Related Impacts Appendix 12.4 indicates that a fish entering the power tunnel would experience a rapid, initial pressure increase of approximately 2.5 atmospheres (atm), then an immediate drop in pressure equivalent to approximately 3 atm [Čada] et al. (1997) recommended that pressures within the power tunnel be maintained at or above 60% [percent] of the pressure value to which fish were acclimated prior to entrainment. 5

8 Section 6.0 notes that blade strikes and the rapid decrease in pressure immediately behind the turbines will be the predominant causes of fish injury and mortality for the Tazi Twé power generating facility. No further information or analysis is presented regarding pressure impacts on fish within the power tunnel or on residual impacts of the changing pressure (both increasing and decreasing), to entrained fish. a) Identify what fish species (including age and size range) may be attracted to the [P]roject intake. b) Provide a rationale for the range of exclusion bar rack spacing chosen, including: i. Why a visual deterrent was chosen over providing a more exclusive physical barrier; and ii. Benefits of and optimal sizing for, visual deterrence for potentially impacted [VC] fish. c) Provide additional detail and identify residual impacts including mortality predictions, on [VC] fish from entrainment and impingement at the intake. Be sure to include: i. Potential impacts from the changing pressure (i.e., increasing inside the power tunnel and decreasing behind the turbines); ii. Potential impacts from blades trikes; iii. Potential impacts on fish populations in Black Lake and Middle Lake; and numbers of fish likely to be impacted including species, age and size-specific mortality estimates. a) The use of habitats near the water intake channel opening in Black Lake, as well as within the water intake approach channel itself, has been evaluated in a technical memorandum provided in Attachment E. The potential for fish to be attracted by the flows at the water intake channel opening was assessed, and the results of the assessment described in Attachment E. Based on the assessment, it is considered unlikely that fish will be attracted to the water intake. bi) For the exclusion bar rack to act as an effective physical barrier to fish, bar spacings would need to be reduced to a size so small that significant head losses would occur. The magnitude of the potential head loss would likely be sufficient to preclude development of the Project, thereby preventing realization of the Project benefits described in the EIS. The effectiveness of the proposed exclusion bar rack as a physical and/or visual deterrent to fish was recently assessed in greater detail than that provided in the EIS; a detailed description of the results is provided in the technical memorandum included as Attachment E (also see part one of the Agency s Comment Number 5, above). The results of the updated assessment indicate that the proposed exclusion bar rack spacing is not likely to serve as an effective physical or visual barrier to most fish species and life stages. Engineering considerations related to the fish screen requirements at the power tunnel water intake are presented in Attachment D. bii) The results of the assessment in Attachment E indicate that when physical and behavioural (i.e., based on visual stimulation) deterrence are considered together, the exclusion bar rack would only become effective at spacing sizes of 70 mm or less (Attachment E). As discussed in bi), such reductions in exclusion bar rack spacings may result in significant head losses. ci) Potential impacts to entrained fish from pressure increases and decreases within the power tunnel have been assessed, and the results summarized in a technical memorandum (Attachment E). Rates of pressure-related injury and mortality are expected to be negligible for physostomous fish (i.e., fish that are able to vent their swim bladders via a pneumatic duct to the esophagus) and less than 2% for physoclistous fish (i.e., fish that are unable to vent their swim bladders). cii) The technical memorandum (Attachment E) also includes predictions of impingement at the exclusion bar rack, as well as mortality rates for turbine-passed fish (see part one of the Agency s Comment Number 5, above). ciii) The potential for impingement and entrainment of fish at the water intake in Black Lake to affect fish populations downstream in Middle Lake has been evaluated in the technical memorandum included in 6

9 Attachment E. A second technical memorandum was developed to assess the numbers, sizes and species of fish that may be lost from Black Lake as a result of impingement or entrainment at the water intake (Attachment F). An assessment of potential effects to select populations of VC fish species in Black Lake has been also summarized in the Attachment F memo. Comment Number 6: Section 12.4, Table (page 12-24); Section (page 12-68); Appendix 12.1; Appendix 12.2, Section (page 17). Spring Flow Mitigation on the Fond du Lac River: Appendix 12.2 states that [m]inimum riparian flows will be maintained at 70 m 3 /s [cubic metres per second] during the spring pre-spawning and spawning period (May 1 to June 30) and at 40 m 3 /s during the rest of the year to maintain critical fish habitats (e.g., overwintering areas) and fish populations within the Fond du Lac River. Although overwintering and spawning habitat impacts were assessed for a total of four flow scenarios (210, 50, 40 and 30 m 3 /s) in Appendix 12.1, we note that impacts at flows of 70 m 3 /s were not modelled or described in conjunction with these results. As the [P]roponent is proposing that an increase in riparian flow to 70 m 3 /s be considered a mitigation measure (as per Volume 2), the impacts being mitigated should be made clear. a) Provide a comparison of the flow of 70 m 3 /s with the other four flow scenarios and explain why 70 m 3 /s was chosen over other potential flows as mitigation for the Fond du Lac River. b) Explain how a flow rate of 70 m 3 /s will be achieved and maintained between May 1 and June 30 in the impacted Fond du Lac River. a) Overwintering habitat for fish in the Fond du Lac River was assessed based on four flow scenarios (210 m 3 /s, 50 m 3 /s, 40 m 3 /s and 30 m 3 /s) and spring spawning habitat was assessed based on six flow scenarios (302 m 3 /s, 112 m 3 /s, 400 m 3 /s, 210 m 3 /s, 510 m 3 /s and 320 m 3 /s) (EIS Appendix 12.1). Flows in the Fond du Lac River reach a minimum during winter, and then begin to increase in late April as ice and snow begins to melt. This natural rise in flows during spring is thought to trigger spawning behaviours of longlived riverine fishes, including Arctic grayling (Thymallus arcticus) (EIS Section ). Project operation during winter is anticipated to reduce riparian flows to a target value of approximately 40 m 3 /s. To mimic the natural rise in flows that would occur in spring, the Proponent will reduce the amount of water entering the water intake in April so that flows in the Fond du Lac River climb from 40 m 3 /s to the spawning incentive flow of 70 m 3 /s by May 1 each year. The value of 70 m 3 /s was selected so that the increase in flows during spring under conditions of Project operation would mimic the increase in flows associated with the natural hydrograph. Increasing spring flow levels to 70 m 3 /s represents a near doubling of winter riparian flows and thus should be noticed by resident fish as a warning that spring is arriving and that the spawning season will soon commence. Responses of fish to spawning cues should therefore remain relatively unchanged, despite Project operation. The 70 m 3 /s spawning incentive flow is intended to trigger spawning behaviours so that fish are able to assemble or congregate near spawning areas and initiate spawning activities when spring flows (e.g., 302 m 3 /s, 112, 400, 210, 510 and 320 m 3 /s) and temperatures (EIS Section ) are conducive to successful spawning and rearing. The increase from 40 to 70 m 3 /s is essentially an advance notice that high spring flows and the spawning season are approaching. The increase in riparian flow from 40 to 70 m 3 /s will occur by May 1 each year so that the timing of spawning and rearing activities will remain relatively unchanged from pre-project 7

10 conditions. Natural increases in spring flows associated with snowmelt and runoff are expected to surpass the 70 m 3 /s trigger flow within a few days to weeks. b) The flows in the Fond du Lac River will be managed by reducing the amount of water entering the intake in April so that flows in the Fond du Lac River climb from 40 m 3 /s to the spawning incentive flow of 70 m 3 /s by May 1 each year. Comment Number 7: Annex III, Sections and (pages 82 and 83); Section 12.1, Table (page 12-2) Spawning Surveys and Population Estimates: Table identifies [eight] fish species (Arctic grayling, cisco sp. [Coregonus sp.], lake trout [Salvelinus namaycush], lake whitefish [Coregonus clupeaformis], longnose sucker [Catostomus catostomus], northern pike [Esox lucius], walleye [Sander vitreus] and white sucker [Catostomus commersonii]) as [VCs] of the [P]roject primarily due to their importance to the Black Lake First Nation, the outfitter at Camp Grayling and local anglers. Annex III notes that spawning surveys were completed for Arctic grayling in Fond du Lac River and that [f]all and winter spawning surveys were completed in Black Lake to identify the most likely locations of lake trout, lake whitefish and burbot [Lota lota] spawning habitat so that potential effects of the Project on spawning and rearing habitats of these species can be assessed. It also notes that [m]ark-recapture population estimates for Arctic grayling within the Fond du Lac River were conducted in 2010 to determine the size of fish populations potentially affected by the operation of the power facility. In order to understand whether further survey work is required. Provide a rationale why spawning surveys and population estimates were not undertaken for all VC fish species in Black Lake and Middle Lake. The initial fish and fish habitat studies completed for the Project were designed to address potential issues identified in the draft Terms of Reference that was issued by the Agency and the Government of Saskatchewan in The studies were completed based on the understanding of the Project at that time (i.e., in 2010 and 2011). Since issuance of the draft Terms of Reference, a number of Project components and activities that could affect fish and fish habitat have been changed, removed, or replaced. Based on the initial design for the Project, it was anticipated that water levels in Black Lake would be altered as a result of Project operation. The Proponent was considering converting Black Lake into a regulated reservoir by constructing a dam at the lake s outflow to the Fond du Lac River. It was anticipated that high water levels in the lake during summer and draw-down of the water levels during winter could potentially affect spawning habitats in the lake/reservoir. For this reason, spawning surveys were initiated in Black Lake; fall/winter spawning lake trout, lake whitefish and burbot were the first species assessed. The goal was to identify potentially sensitive, shallow water fish habitats that would provide suitable spawning and rearing habitat for these species. Following completion of these surveys, the Project design was modified to include a submerged weir at the Black Lake outflow. The submerged weir is designed to maintain water levels in Black Lake such that water levels remain within the natural range of variation, despite Project operation. Consequently, effects to shallow-water spawning and rearing habitats, and fish populations that depend on those habitats, are not expected to occur. For these reasons, spawning surveys in Black Lake were not included in the subsequent field programs. 8

11 Because the addition of the submerged weir at the Black Lake outflow will effectively mitigate potential effects to spawning and rearing habitats in Black Lake, the water intake structure is considered to be the primary Project component that could impact fish populations in Black Lake. Population estimates were not completed for Black Lake fish species; however, the likelihood for fish to interact with the water intake was discussed in EIS Appendix 12.3, and a more detailed assessment of fish losses was completed and summarized in a recent technical memorandum (Attachment F). The technical memorandum includes an estimation of potential entrainment rates for fish that are most likely to interact with the water intake, as well as an assessment of potential implications for fish populations in Black Lake. Monitoring will be completed during the first year of Project operation to confirm the numbers of fish leaving Black Lake and verify that no effects to fish populations are occurring. Spawning surveys and population estimates were not completed for Middle Lake because no flow-related impacts to fish habitats and fish populations are expected to occur. Because water diverted through the Project infrastructure will mix with riparian flows in the Fond du Lac River at the tailrace outlet location upstream of Middle Lake, the amount of water flowing into Middle Lake will remain unchanged relative to natural conditions, despite Project operation. Water levels in Middle Lake will be maintained; therefore, no effects to fish and fish habitat are expected to result from changes in flow induced by the Project. Potential effects to fish populations in Middle Lake that may result from entrainment and downstream passage of fish at the water intake in Black Lake were assessed, and the results summarized in a technical memorandum (Attachment F). Results of the technical memorandum will be verified through monitoring. Comment Number 8: Section (page 12-44) Use of Explosives: The EIS states that [a] detailed Blasting Plan will be developed for the Project and that it will comply with DFO [Fisheries and Oceans Canada] Guidelines for the Use of Explosives in or Near Canadian Fisheries Waters (Wright and Hopky 1998). Advice provided on the DFO website with respect to explosives, is intended to minimize impacts on fish and fish habitat. a) Discuss how the Blasting Plan will incorporate DFO Measures to Avoid Causing Harm to Fish and Fish Habitat, as per the advice provided on the DFO website: b) Confirm that the detailed Blasting Plan will be sent to DFO for review, prior to the use of any explosives. a) The Blasting Plan will incorporate a number of Measures to Avoid Causing Harm to Fish and Fish Habitat. The measures specific to blasting that will be incorporated in the Plan included: Timing: to protect sensitive lifestages (i.e., eggs and larvae) and activities (i.e., spawning) blasting activities that have the potential to harm fish will not be completed within the applicable restricted activity timing windows. The objective will be to avoid damage to eggs and fry, and ensure adult fish are not deterred from using regular spawning areas. Isolation of in-water work areas: fish will be excluded from in-water work areas; exclusion methods may include the installation of cofferdams, aquadams, or other barriers deemed appropriate for site conditions and effective exclusion of fish. Fish will be captured from isolated in-water work 9

12 areas and released, unharmed, outside the in-water work area. Blasting will not commence until fish salvage operations are complete. Additional measures, such as the strategic placement of aggregate material to deaden vibrations, will be implemented, as needed. Charge weights and blasting sequences: the Blasting Plan will describe the charge weights to be used during blasting, as well as the blasting sequence and delay times between charge detonations. These will be optimized to minimize potential shock wave and overpressure stresses to fish and fish and fish habitat. Overpressures will be calculated according to DFO s Guidelines for the Use of Explosives in or near Canadian Fisheries Waters (Wright and Hopky 1998). The finalized Blasting Plan will identify the range or distance over which any overpressure will exceed 100 kilopascals (kpa). Charge weights will be minimized and delay times between detonation times optimized to protect fish and fish habitat. Charges may be subdivided into a series of smaller charges in blast holes (i.e., decking with a minimum 25 millisecond (1/,1000 seconds) delay between charge detonations. Blast holes may be back-filled with sand or gravel to confine the blast. Blasting mats may be placed over the blast holes, if required, to minimize scattering of blast debris. Ammonium nitrate explosives: Although ammonium nitrate explosives may be used as part of the blasting program for the Project, a Site Water Management Plan will be implemented to monitor and manage the potential for release of toxic by-products so that fish habitats and fish are protected. Other avoidance and mitigation measures applicable to blasting activities will be incorporated into the Project, in addition to those described in the Measures to Avoid Serious Harm to Fish and Fish Habitat (DFO 2013). The Project-specific limit for allowable ground vibrations during blasting is set at 13 millimetres per second (mm/s). Appropriate set-back distances will be determined for blasting of the water intake foundation, powerhouse foundation and tailrace channel so that potential effects to fish and fish habitats in nearby waterbodies and watercourses will be minimized. b) The detailed Blasting Plan will be sent to DFO for review and approval prior to the use of any explosives on site. A draft annotated Table of Contents is provided in Attachment A. Comment Number 9: Section 12.4, Table (pages and 12-27); Section (page 12-50) Flow Impacts: Table notes in two places that for shutdowns longer than 15 minutes during the spring spawning and rearing period (May 15 to July 15) and low winter flow period, downstream flows will be maintained by bypassing water around the powerhouse turbine generator units using a bypass conduit. With respect to scheduled power tunnel inspections, Section states that [e]ffects to fish and fish habitat would be expected to be reduced if power tunnel inspections were scheduled for early May to coincide with the start of the spring freshet when flows are increasing, but prior to the start of spring fish spawning. There does not seem to be any discussion within the EIS about potential effects to the bypassed sections of the Fond du Lac River should there be a need for an extended shutdown (emergency or otherwise) of the flow down the tailrace (i.e., all turbines and bypass). Although there will always be natural variation in river flows and lake water levels, system fluctuations all contain the potential for impacts to fish and fish habitat. Information is needed to understand the impact of flow variation and rates of change in the Fond du Lac River (and immediately downstream) on fish and fish habitat during maintenance activities. 10

13 a) Define the low winter flow period as discussed above including magnitude of flow expected at that time. b) Explain why flows will not be diverted through the bypass at all times of the year for shutdowns equal to or greater than 15 minutes. c) What will be the potential effects to fish and fish habitat in reaches 3 through 21 of the Fond du Lac River (at varying times of year) if 110 to 190 m 3 /s of flow from the powerhouse is suddenly required to be diverted. Include proposed mitigation for the potential effects if necessary. The details of this IR response can be found in Attachment G. A summary is provided below. a) The low winter flow period begins in October and ends May 1, when the spring spawning incentive flow is initiated and riparian flows are increased to levels at or above 70 m 3 /s. During this time, riparian flows in the Fond du Lac River will be lower than they would be between May and September; this trend is similar to pre-project conditions. When the Project is operating during the low winter flow period, Fond du Lac River flows will be maintained at or above 40 m 3 /s; in spring, the amount of water diverted through the facility will be reduced so that riparian flows increase and the spawning incentive flow can be achieved. b) During the spring spawning and rearing period (May 15 to July 15) and during the winter low flow period (November through April), an unplanned shut down lasting longer than 15 minutes will trigger the release of flow through the facility s bypass conduit. The bypass conduit will divert flows around the turbine units so that flows and water levels in the Fond du Lac River downstream of the tailrace outlet can be maintained. Flows to the Fond du Lac River from the natural Black Lake outlet would also increase slowly under these conditions as water levels in Black Lake respond to reduced power tunnel flows. Outside of the spring spawning and rearing period and the winter low flow period, unplanned shut downs lasting longer than 15 minutes will not trigger initiation of bypass flows. The known Arctic grayling spawning and rearing habitats downstream of the tailrace outlet and upstream of Middle Lake are generally dry outside of the spring spawning and rearing period and are therefore unsuitable for use by fish. Flow will be bypassed during the low winter flow period to take advantage of the warming tailrace flows and minimize the potential for frazil and anchor ice formation downstream of Middle Lake. Subsequently, implementation of a flow bypass mitigation measure outside of the spring spawning and rearing period or the low winter flow period would provide no additional benefit to fish. Dewatering of the power tunnel for planned inspections and maintenance will be scheduled for late July of average- to high-flow years; power tunnel dewatering will not be scheduled during the spring spawning and rearing period (May 15 to July 15). This will maintain spawning habitats and behaviours and protect eggs and fry so that populations of spring spawning fish can be maintained. By scheduling power tunnel dewatering in late July of average- to high-flow years, it will be possible to take advantage of the naturally high flows that are expected to help dampen water level fluctuations in Black Lake, the Fond du Lac River and Middle Lake. This will help minimize stranding of fish; even young-of-the-year fish are expected to have sufficient swimming ability to avoid stranding by this time. Only one turbine unit at a time will be taken out of service for monthly and annual inspections and maintenance. Between January and early April, low flows may necessitate the use of only one turbine unit; inspections and maintenance may be carried out on the second turbine unit when it is out of service. Between April and December, when larger flows would generally support operation of two turbines, shutting down one turbine for an eight-hour period is expected to increase the water level in Black Lake by metres (m) and reduce the 11

14 water level in Middle Lake by 0.05 m. Water level fluctuations of this magnitude are not anticipated to affect fish and fish habitats. For these reasons, it is unlikely that initiation of a flow bypass during regular summer or fall flows would provide any additional benefit to fish. c) Under a plant shut down scenario, water levels in Black Lake would slowly rise in response to the lack of power tunnel flows; larger volumes of water will begin to slowly spill over the submerged weir at the Black Lake outlet. Following cessation of power house flows and before larger riparian flows from the natural Black Lake outlet reach Middle Lake, water levels in Middle Lake are expected to recede. Once larger riparian flows from the natural Black Lake outlet reach Middle Lake, water levels in Middle Lake are expected to gradually increase. Water levels in Middle Lake would normalize (i.e., recede) again once the powerhouse flows resume and Black Lake water levels return to normal. An assessment of ramping rates for Middle Lake was included in EIS Appendix 10.3; the objective of the assessment was to determine whether ramping rates were sufficiently small to protect fish from becoming stranded when the power plant is re-commissioned and water levels recede. Because no specific regulatory guidelines are available for ramping, a maximum water level reduction rate of 5 to 10 centimetres per hour (cm/h) was incorporated into the design. This criterion is considered sufficiently protective to minimize fish stranding. A supporting assessment was also completed following receipt of this IR. The objective of the supporting assessment was to examine the rates and magnitude of water level changes in Black Lake and Middle Lake following a plant shut down for tunnel inspection and maintenance at various times of the year. Changes to flows and water levels in the Fond du Lac River, and subsequently, the likelihood that fish would become stranded, was also considered, based on the changes predicted for Black Lake and Middle Lake. Because there is no direct flow control on the outlet of Black Lake, flow responses in the Fond du Lac River (both increases and decreases) are controlled by changes in Black Lake water level and thus occur over periods of days and weeks, rather than hours. It is anticipated that cessation of flows through the power generating facility would cause Black Lake water levels to rise by approximately 24 to 35 centimetres (cm) over an approximately two week period. Larger volumes of water would begin spilling over the submerged weir at the natural Black Lake outflow and water levels in Black Lake would slowly normalize. Flows in the Fond du Lac River would gradually increase; no pulse of flow is anticipated due to the gradually increasing release of water from Black Lake. This is expected to minimize the potential for stranding of fish. Water levels in Middle Lake would initially decrease in response to cessation of power tunnel flows; the lowest overall decreases in water levels are expected to occur in July and August. To minimize ramping rates and lake level effects, shut downs for power tunnel inspection and maintenance will be scheduled during July of average- to high-flow years and will have flows slowly cut off and started up over periods of one to two weeks. The relatively large volumes of water flowing into Middle Lake during July are expected to dampen the effects of a plant shut down so that water level fluctuations and potential effects to fish habitats are minimized. By gradually reducing the amount of water flowing through the facility over a one or two week period prior to power tunnel inspection, it is anticipated that a maximum hourly drawdown rate of 0.4 cm/h can be achieved for Middle Lake. Similarly, if power tunnel flows are resumed gradually over a one to two week period following completion of the inspection and power tunnel maintenance, it is estimated that the maximum hourly rate of water level increase within Middle Lake can be maintained at less than approximately 0.5 cm/h. If the routine inspection date should fall within a low-flow year, power tunnel inspection and maintenance can be delayed until the occurrence of an average- to high-flow year. Comment Number 10: Section (page 12-69); Appendix 12.2, Section 3.4.1, Table 7 (page 26) Arctic Grayling Spawning Habitat: Page notes that [u]nder Q90 average high spring flows (i.e., 510 m 3 /s), the amount of suitable habitat available to Arctic grayling is less than that available under historically average (i.e., 400 m 3 /s) or historically low 12

15 (302 m 3 /s) spring flows. At very high flow rates, increases in water depth and changes in water velocity may work in combination to render some traditional spawning areas temporarily unusable. Therefore, Project operation during high flow years is expected to result in a general improvement (or maintenance) of suitable spawning habitat. However, Appendix 12.2, Table 7 on page 26/34 shows that during Project operation in high flow years, the predicted area of suitable spawning habitat is less than the low, average and high spring flow baselines. a) Explain the discrepancy between the above statement and the information presented in Appendix b) Update the effects analysis based on the response to 7a) for the project s residual effects on fish that have been identified as [VCs]. a) Please refer to EIS Appendix 12.1, Table 18. This table shows the quantity of unsuitable, poor, moderately suitable, and suitable habitat predicted in Fond du Lac River reaches 2 through 22 (i.e., the extent of the river between Black Lake and Middle Lake). The quantity of suitable spawning habitat for Arctic grayling under baseline conditions is expected to be the lowest at the Q90 (510 m 3 /s) high flow. For the segment of river between Black Lake and Middle Lake (i.e., reaches 2 through 22), Project operation at Q90 high flows is anticipated to alter Arctic grayling spawning habitat such that the area of suitable spawning habitat increases by 8.4 %. Table 7 of EIS Appendix 12.2 only shows data for Fond du Lac River reaches 3 through 21. To be conservative in estimating the amount of fisheries offsetting that would be required for the Project, reaches 2 and 22 were removed from consideration; spawning habitats in these reaches were expected to be effectively maintained due to the ameliorating effects of the weir and recombination of riparian and Project flows, respectively. In fact, based on the assessment provided in EIS Appendix 12.1 (Table E1), it is anticipated that Arctic grayling spawning habitat in reaches 2 and 22 will improve by approximately 63.0% and 37.0%, respectively. The data presented in EIS Appendix 12.2, Table 7 represents the river reaches (i.e., reaches 3 through 21) that were expected to be influenced the most by the Project, without the moderating influence of factors like the submerged weir. By basing the assessment of offsetting needs on fish habitat losses in these reaches, it was anticipated that a more conservative approach to fisheries offsetting could be achieved. b) Based on the response to the Agency s Comment Number 10a) (above) it is not anticipated that updates to the effects analysis will be required. Comment Number 11: EIS Guidelines, Sections (page 14), (page 27) and 16 (page 38); Section 12.2 (page 12-4); Appendix 12.2, Section 3.3 (page 23) Monitoring: Section states that [t]he [P]roponent will identify and justify the indicators and measures of ecosystem health and integrity used for analysis and relate these to the identified VCs and proposed monitoring and followup measures. Section states that in documenting the analyses included in the EIS, the [P]roponent will identify any proposed follow-up and monitoring activities, particularly in areas where scientific uncertainty exists in the prediction of effects. 13

16 Section 16 notes that [i]n the EIS, the [P]roponent will describe the monitoring activities at all stages of the [P]roject, the p[p]roponent s proposed commitment to implementing these activities and resources provided for this purpose. There are numerous places in the EIS where the proponent notes that the [P]roject is not expected to result in impacts to fish and fish habitat. For example, Section 12.2 states that [n]o Project effects on fish and fish habitat are anticipated for areas where hydrological changes do not occur. And Appendix 12.2 states that with respect to entrainment, this residual serious harm to fish is not anticipated to impact the sustainability and productivity of CRA fisheries in the area. The EIS does not provide the required information (as per the EIS Guidelines) on monitoring that would assist in the verification of these types of predictions, and the residual [P]roject impacts. In addition, anticipated contingency measures for failed avoidance, mitigation or offsetting measures are not described. a) As per the EIS Guidelines document, for all [P]roject effects relating to [VC] fish and fish habitat, provide a monitoring plan that will be implemented to verify: i. predicted effects (including if no effects were predicted), effectiveness of mitigation measures and standards implemented to avoid or mitigate serious harm to fish and; to offset serious harm to fish and fish habitat; and ii. a description of the contingency measures and associated monitoring measures that will be put into place if the measures implemented to either offset or mitigate serious harm to fish are not successful. The Conceptual Fisheries Offsetting Plan has been revised to include monitoring (i.e., revised EIS Appendix 12.2, Section 6.0 Fisheries Offset Monitoring Program) and contingency plans (revised EIS Appendix 12.2, Section 7.0 Contingency Measures) for the protection of fish and fish habitat. A copy of the revised Fisheries Offsetting Plan can be found in Attachment H. i) One objective of the Fisheries Offset Monitoring Program is to confirm predictions of effects to fish and fish habitat that were made in the EIS. Monitoring will be completed for Project-environment interactions that were included in the assessment of effects to fish and fish habitat (EIS Section 12.0 and EIS Appendix 12.2) but identified as being unlikely to result in residual serious harm to fish. The results of this monitoring will be used to verify that avoidance and mitigation measures are installed and functioning as planned. Similarly, Project components and activities that are anticipated to result in serious residual harm to fish will be monitored to confirm that avoidance and mitigation measures are installed and functioning as planned, and to verify that offsetting measures are sufficient to effectively minimize effects to fish populations. ii) The finalized Fisheries Offsetting Plan will provide a description of contingency measures that may be implemented in the event that avoidance, mitigation and offsetting measures prove insufficient to protect fish and critical fish habitats (revised EIS Appendix 12.2, Section 7.0; see Attachment H). If monitoring results indicate that contingency measures are required, monitoring will be completed to confirm these measures are installed and functioning as planned. Comment Number 12: Vegetation, Section 14 (page 14-39) The EIS identified the potential indirect effect of deposition of sulphur dioxide and nitrogen dioxide through fugitive dust emissions leading to the acidification of wetlands. This indirect effect was not carried over to the residual effects analysis. a) Quantify the amount of and aerial extent of deposition. 14