Guidelines for Mining in - Glockner

1 ENVIRONMENTSARIDARIDARIDARIDARIDG uidelines forMining inMining Operations DivisionMining Operations DivisionMining Operations DivisionMining Operations DivisionMining Operations DivisionDepartment of Minerals & EnergyDepartment of Minerals & EnergyDepartment of Minerals & EnergyDepartment of Minerals & EnergyDepartment of Minerals & Energy100 Plain Street100 Plain Street100 Plain Street100 Plain Street100 Plain StreetEast Perth WA 6004 East Perth WA 6004 East Perth WA 6004 East Perth WA 6004 East Perth WA 6004 ISBN 0 7309 7802 8 JUNE 19961 Guidelines for Mining in arid EnvironmentsTable of Zone EnvironmentsArid Zone EnvironmentsArid Zone EnvironmentsArid Zone EnvironmentsArid Zone Land StudiesBaseline StudiesBaseline StudiesBaseline StudiesBaseline Site Overburden and Tailings ( Growth Medium )

2 Rock Ecological Use ObjectivesLand Use ObjectivesLand Use ObjectivesLand Use ObjectivesLand Use PlanningSite PlanningSite PlanningSite PlanningSite ManagementOperational ManagementOperational ManagementOperational ManagementOperational Topsoil of Harvesting and Storage Mining Landform Mine Dewatering and Dust RehabilitationLand RehabilitationLand RehabilitationLand RehabilitationLand Topsoil Erosion Control and Water and Methods of Monitoring and Completion CriteraRehabilitation Monitoring and Completion CriteraRehabilitation Monitoring and Completion CriteraRehabilitation Monitoring and Completion CriteraRehabilitation Monitoring and Completion ReferencesSelected ReferencesSelected ReferencesSelected ReferencesSelected References3939393939 PageGuidelines for Mining in arid Environments2 Figure arid and semi- arid zones of types of arid and semi- arid of interstitual salt from a Murchison in species richness in a typical hummockgrassland following percentage cover of the hummock grassin a typical spinifex community follwing site plan in a hypothetical arid zone - Harvesting topsoil with/without.

3 The incorrect/correct method of stockpiling - Poorly/well located topsoil natural slope profile, an ideal profile for a waste of angle of slope on revegetation and erosion26 Figure slope profile for most waste dumps, detail ofwaste dump construction technique27 Figure construction that allows progressive rehabilitation28 Figure treatment of a hypothetical saline waste dump30 Figure (moonscaping)32 Figure of diverting water flow by making earth 8 Regeneration curve of a typical dominant hummock grass(spinifex) and its application as a completion Guidelines Provided by the Department of Minerals and Guidelines Provided by the Department of Minerals and Guidelines Provided by the Department of Minerals and Guidelines Provided by the Department of Minerals and Guidelines Provided by the Department of Minerals and Handling and Germination in the Main arid Zone Seed Handling and Germination in the Main arid Zone Seed Handling and Germination in the Main arid Zone Seed Handling and Germination in the Main arid Zone Seed Handling and Germination in the Main arid Zone Seed &

4 Appendices3 Guidelines for Mining in arid EnvironmentsIntroduction11111 This Guideline concentrates on the environmental management of Mining ratherthan the administrative processes for obtaining project approval. Information on thepreparation of proposal documents (NOIs), and on other government approvalprocedures, is available in specific Guidelines provided by the Department of Mineralsand Energy (Appendix 1). Mining and mineral processing is a very diverse activity in Western Australia, withdifferent Mining methods and processing technologies scattered over a vast also takes place in a wide range of environmental contexts which imposeparticular problems in controlling environmental impacts and constraints on themanagement and rehabilitation of mined 78 percent of Western Australia s land area lies within the arid andsemi- arid bio-climatic zones.

5 A variety of minerals including most of the State s goldand nickel and all of its iron ore, copper, manganese and salt is currently extractedfrom mines in arid areas. Potentially economic uranium and phosphate resourcesalso occur in our semi arid to arid challenges to environmental management are best approached from an ecologicalrather than an industry type engineering perspective. Therefore, this Guideline isfocused on the environmental management of Mining within the State s vast is stressed that the information contained within this document is presented as aguideline, and it is expected that individual operators will be innovative in achievingenvironmental and rehabilitation objectives.

6 As new techniques are developed andinformation from various case study examples become available, this Guideline willbe for Mining in arid GENERALA ustralia is the driest continent and therefore it is not surprising that the majority ofmining operations in Western Australia are located in the arid (rainfall <250mm) or semiarid (<350mm) zones. Approximately 388,917 km2 of Western Australia ( percentof the State) is tropical or Mediterranean semi-desert. A larger 1,593,803 km2 ( ) is technically desert. In order to manage projects in these areas it is importantto understand the characteristics of Australian arid well as being the driest continent, Australia is also the oldest and most features of the ancient western shield are erosional, weathered-down lateriticplains and breakaways (shield desert), gibber plains, residual ridges, monadnocksand granite tors.

7 The Hamersley Ranges (Banded Iron Formations) are deep waterchemical sediments that have been gently folded and subsequently processes form colluvium, sediments from erosional processes aredeposited by water as alluvium along the drainage lines or by wind as aeolian desertsand RAINFALL/EVAPORATIONR ainfall in the arid zone is low with large annual variations. arid environments arenevertheless seasonal with the probability of significant rainfall being higher in particularmonths. The bioclimates of the arid zone in Western Australia are mapped in Broadly, summer rainfall dominates in the Pilbara and central desert areas ofWestern Australia and winter rainfall in the semi- arid southwest and eastern broad intervening area of mid-western Australia, the mulga zone, is a transitionzone between winter and summer rainfall dominance.

8 Within this zone both winterand summer rainfall events contribute significantly to biological rates of arid environments are many times that of rainfall. A consequenceof this is that airborne salt of marine origin (cyclic salt) deposited in rainfall, becomesconcentrated in the soil profile, in the weathered geological profile or in inland drainage lines terminate in salt pans or playa lake systems (which arehypersaline environments). SOILSS oils in the arid zone are generally shallow, often skeletal, and show little verticalstructure due to a lack of organic matter.

9 They are heavily weathered, containingmostly insoluble elements such as iron and aluminium (hence the reddish colour)and are of low fertility (often deficient in phosphorous, potassium and trace elements).The red-brown earths of much of the mulga zone are slightly acidic to neutral in pH( ) but basic soils occur near outcrops of calcareous rocks such as calcrete ordolomite (pH ). Changes in soil type can be clearly identified by their Zone Environments222225 Guidelines for Mining in arid EnvironmentsFIGURE arid AND SEMI arid ZONES OF WESTERN AUSTRALIAAND THE BIO-CLIMATE OF THE ZONES WITHIN THEMG uidelines for Mining in arid LAND SYSTEMS/VEGETATIONArid zone land systems are clearly defined by the landforms and drainage systems frequently occur in repetitive cycles with each unit consisting oftributary channels, main channels and distributary (outwash) channels.

10 Withdecreasing elevation the pattern is repeated but the size of the creek systems ismagnified. Vegetation types often recur consistently in the same part of the creekcycle but at different elevations in the drainage system. A typical example are thegroved stands of mulga, Acacia aneura, which occur on gently sloping outwash plainsvarying in area from less than one square km, in early creek cycles, to hundreds ofsquare kilometres in later density indicates the patterns of water concentration and storage createdby the landform. Biological productivity in the arid zone is dependent on drainageeffects.