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

Project DescriptionDuring operations, the treated sewage effluent will likely be discharged into the mill tailingssystem. The wastewater collection system, which will consist of insulated HDPE pipe installedin the site utilidors, will conform to all applicable regulations and good engineering practice.Where possible the pipes will be designed to flow by gravity. If necessary, a force main will beinstalled. If necessary, pipe that cannot be positively drained will be heat traced. The excess biomass(sludge) produced by the plant will be aerobically digested, stored in a sludgethickening/storage cells and likely disposed in specifically constructed cells in a landfill near oneof the waste rock piles.2.7.4 Solid Waste ManagementDomestic waste will be incinerated, and industrial waste that cannot be incinerated will depositedas landfill in the waste rock pile.2.7.5 Water Use (domestic and process)Water required for camp use and operations makeup water will be pumped from a lake or riversource into a water storage tank in the mill. To prevent fish entrapment, DFO’s “FreshwaterIntake End-Of-Pipe Fish Screen” guidelines will be followed.Water will be drawn from the storage tank, treated, and pumped to the camp and other locationswhere potable water is needed. Potable water treatment will consist of filtration and purificationtreatment. Currently, several large lakes along the access road are being considered for watersupply. The estimated water consumption volumes are being evaluated as part of the prefeasibilitywork, which is expected to be completed by summer 2008.2.7.6 Diversion and Collection SystemsThe site water management system will be designed and operated to meet the followingobjectives:• To intercept and collect any waters that may have been in contact with mining areas, minewastes, tailings, or the process plant;• To divert as much water as possible around the mine areas to avoid contact, and to directthese to downstream drainage systems; and• To either store contact waters in the TMF, or otherwise to sample contact waters forpotential contaminants and, if necessary, to treat to remove contaminants to meetpermitted water quality guidelines prior to release.Preliminary water balance analyses indicate that the TMF will have a net negative water balance,i.e., water losses, primarily due to water storage in the voids of the tailings, will exceed thevolume of direct precipitation and runoff in the TMF catchment. Hence, there will be anopportunity to direct other site contact waters to the TMF to be used as process makeup water.Where contact waters have the potential to contain suspended solids, such as runoff from haulroads, all drainage will be directed to sedimentation ponds for removal of suspended solids.Drainage from haul roads would be released after removal of suspended solids, provided it issampled and shown to meet water quality guidelines for discharge.January 2008 Hackett River Project – Project Proposal Sabina Silver CorporationReport Version B.1 2–34 Rescan Environmental Services Ltd. (Proj. #833-2)