Mining in Remote Areas Issues and Impacts - MiningWatch Canada

Case study: Tailings leaks at FaroThe Faro lead-zinc mine in the Yukon has had a history of problems with its tailingspond. (31)From 1969 to 1975 at least a half-dozen leaks in the tailings impoundment systemwere monitored. There were seepages of high pH effluent, contaminated with elevatedlevels of lead, zinc and arsenic, into Rose Creek. In addition to these leaksthere were a number of major failures of the tailings pond resulting in large releasesof effluent into Rose Creek.In March of 1975, two dikes failed and 54 million gallons of contaminated tailingswater flowed into Rose Creek, depositing tailings downstream for a distance of 15 km.Charges were laid by DIAND and the Environmental Protection Service. The companypleaded guilty to one of the charges and was fined the current maximum daily fine of$5,000, but the fine was reduced to $4,500 on appeal.Another episode occurred over a several month period in mid-winter of 1976, whenhighly toxic levels of cyanide were released into Rose Creek. Fisheries officials consideredthat this spill resulted in "the waters of Rose and lower Anvil Creek being toxic to[fish downstream to] the Pelly River." Charges resulted in a fine of $49,000.In December, 1979, there was yet another breach of the tailings pond, resulting in aspill of 2.5-4 million gallons of effluent toxic to fish.Acid mine drainageAcid is created when water andoxygen come in contact with sulphide-bearingminerals.The chemical reactionthat takesplace creates sulphuricacid, which inturn is able to dissolveminerals, releasingpotentiallyharmful metals previouslybound up inthe rock. Acid maybe generated undernatural conditionsprior to any disturbancefor miningpurposes. However,mining tends to exacerbateacid generation.Throughoutthe entire miningprocess minerals arebroken down,crushed, andground up, exposingmuch more ofthe sulphide minerals to air and waterthan would occur under naturalAcid mine drainage at Equity SilverMine in BCconditions. Acid drainage occurringat mine sites is known as “acid minedrainage” or AMD for short.According to Keith Ferguson, formerlyof EnvironmentCanada, “Acidmine drainage isperhaps the mostserious environmentalproblem amine can face. . . theproblem is difficultto arrest, and thecosts associated withlong-term pollutionabatement can turna once-profitablemine into an expensiveliability.”(26)There are ore bodiesin Norway that weremined in the 1700sthat are still acidgenerating. Fergusonwas not aware ofany identified acidmine that hadstopped generating acid mine drainageon its own.(26)EnvironmentalImpactslin, 100 km north of the mine. It crossesstreams 69 times, and could open anundisturbed wilderness area to loggingand other developments (e.g., othermines). Mine activities, as well, couldaffect wildlife habitat and water quality,which in turn could impact the salmonruns.Environmental Guidelinesfor Access Roads24and Water Crossings(Ontario Ministry of Natural Resources)Environmental Mining Councilof BC. 1998. Acid Mine25Drainage: Mining andwater pollution issues in BCThis document, produced by the Env i-ronmental Mining Council of BC(EMCBC) discusses different sources andtypes of water pollution, with a focus onacid mine drainage (AMD). It also providesinformation on predicting AMD,and outlines a number of case studieson the various impacts and costs associatedwith this form of water pollution.This report can be obtained by contactingEMCBC (emcbc@miningwatch.org,ph: 250-384-2686).Breaking up rock sets off26 production of toxic cocktail(Vancouver Sun,02/12/88, B1)It is estimated that there are 300 milliontonnes of acid-generating wastes inBC. In 1988, at least 5 of the 16 operatingmetal mines had AMD control programs,and six abandoned mines wereacid generating.Tsolum: Concern for this27 damaged river grows(Victoria Times Colonist,10/10/95, A5)The Mt. Washington mine operatedfor less than 3 years before the company(Mt. Washington Copper) wentinto receivership. Exposed pyrite oresreacted with oxygen and water to formAMD, which leached copper from theore. Copper leachate moved through thewatershed, eventually reaching theTsolum River. For more than 10 yearsthe government has attempted to remedythe problem, spending in excess of$1 million of taxpayers’ money to date.Mining In Remote Areas: Issues and Impacts 7