080121-08MN006-Sabina Hackett River Project Proposal ... - NIRB

Identification of Potential EnvironmentalEffects and Proposed Mitigation• Project activities potentially affecting sediment quality (construction activities, fugitivedust, fuel transport and handling, in-stream construction, discharge or leaking from TMF,discharge of sewage effluent and sludge); and• Project activities directly removing or altering aquatic habitat (lake dewatering, culvertinstallations, construction of dams in water courses, reduction in stream flows belownormal low levels, reduction in lake levels below normal low levels).Project activities that could potentially affect surface water quality and sediment quality couldpotentially affect aquatic organisms by causing a reduction in growth and/or health (e.g.,sublethal toxicity), enhancement of growth and abundances of organisms (e.g., from minornutrient enrichment), mortality of some species (toxicity from metals, or oxygen depravation dueto excessive nutrient enrichment) resulting in shifts in community compositions, or directmortality of all species (toxicity from metals, or oxygen depravation due to excessive nutrientenrichment), causing a reduction in abundances and densities of aquatic organisms in streamsand lakes.Project activities that will remove aquatic habitat will directly affect aquatic organisms byremoving the organisms along with the habitat. Some activities, like lake dewatering, arepermanent, in the sense that those organisms and habitat will be removed. Other activities, liketemporarily lower water levels, are not permanent, and aquatic organisms will recolonize theseareas when they become wetted again.Proposed MitigationThe mitigation measures already described for water quality and sediment quality will helpminimize the potential effects to aquatic life, by minimizing changes to water and sediment.The direct effects caused by habitat removal or alteration will be mitigated via fish habitatmitigation measures, which include creating new habitat for habitat that is lost.Adverse effects to aquatic life (and fish) caused by nutrient enrichment and the subsequentoxygen drawdown inevitable in the lakes in the area can be avoided by having sewage effluentand sludge report to the TMF.7.3.2.7 Freshwater Fish and HabitatThe environmental policy for the proposed Hackett River Project will be consistent with theNational Policy for the Management of Fish Habitat (DFO, 1991). The guiding principle of theDFO policy is “no net loss of fish habitat productive capacity” and a net gain if possible for allindustrial developments in Canada affecting surface waters. Management of the proposedProject will include stringent environmental protection policies and plans. Staff andmanagement will work towards no net loss in fishery resources through a wide range of impactavoidance and mitigation measures, site reclamation and rehabilitation techniques, and habitatenhancement methods.January 2008 Hackett River Project – Project Proposal Sabina Silver CorporationReport Version B.1 7–23 Rescan Environmental Services Ltd. (Proj. #833-2)