U.S. GEOLOGICAL SURVEY OPEN-FILE REPORT 00-429-B Slide Show on Hierarchical Systems Analysis in Karst Terrains: Part B - Analysis of Environmental Impacts of Aggregate Mining By William H. Langer 1 and Kenneth E. Kolm 2 This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards or with the North American Stratigraphic Code. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. 1 U.S. Geological Survey, Denver, Colorado, USA 2 Colorado School of Mines, Golden, Colorado, USA
Hierarchical Systems Analysis in Karst Terrains: Part B Analysis of Environmental Impacts of Aggregate Mining William H. Langer U.S. Geological Survey and Kenneth E. Kolm Colorado School of Mines
Purpose of Presentation • Describe how the hierarchical systems analysis (HSA) can be used to analyze environmental impacts (for example from the mining process). • Describe selected environmental impacts from mining aggregate in karst terrain.
Why Mine Carbonate Rocks? Carbonates are fourth in terms of value in worldwide production of non-fuel mineral resources.
Why Mine Carbonate Rocks? • Carbonates are only acceptable source of stone for some construction, agricultural, metallurgical, industrial, and environmental uses. 69% 54.9% Special Special Uses Uses Aggregate Aggregate 31% 45.1% Limestone Dolomite
Goal Provide a continuing supply of high quality carbonate rocks while sustaining environmental quality.
Why Use Hierarchical Systems Analysis? Landscape or site is mosaic of dynamic systems that operate through complex, interrelated processes. o Impacts to those systems occurs through complex, interrelated processes. Stepwise approach breaks complicated issues into smaller, easier to understand, components.
Hierarchical Systems Analysis Primary Maps Environmental Systems & Databases Examples Impacts Examples (Interp. & Models) Noise • Land surface Dust o Climate Land surface system o Topography Habitat o Surface Water Storm water • Geomorphology Flood o Soils Geomorphic system Erosion / Sed. o Surficial geology & processes o Engineering geology Fluvial • Geology Landslide Subsurface system o Structure Karst o Stratigraphy o Geophysics Earthquake Vibration model • Ground water Ground water system Water table o Aquifer properties o Recharge / Discharge Char No Yes Integrate Complete? with mining
Hierarchical Systems Analysis Characterize Land Use (Mining method) Identify Initiating Events How system changed by mining (Consequences) How system will respond Citizen to changes (Responses) input Evaluate impacts (Risk assessment) Are No Impacts Acceptable? Yes Final mine design ISO 14000 EMS
Mining Method • Quarry or underground mine • Aggregate or dimension stone
Uncertainties • Knowledge o Mining involves development in only partially defined physical, chemical, biological, or human environment. o Very little published information about the impacts of extraction of construction materials in karst terrains. o Engineering / geologic state-of-the-art. • Predictability o Environmental damage often occurs far from the point of impact. o Most of the hydrologic processes operate underground. o Some natural phenomenon are unpredictable. • Change o The natural system is in a state of change due to natural and human activity. • Performance – People make mistakes.
Uncertainties => Environmental Risks Risk commonly is expressed in terms of consequences and the likelihood of the consequences being realized. Initiating events make risks become consequences.
Environmental Risk Assessment (Borrow from process) I. Familiarization and description II. Potential impact II A. Identify II B. Risk identification initiating events characterization Identify Analyse Likelihood consequences consequences analysis III. Identify risk contributors IV. Opportunities for risk reduction V. Sensitivity Analysis
Hierarchical Systems Analysis Mining method Identify Initiating Events How system changed by mining (Consequences) How system will respond Citizen to changes (Analysis) input Consider mitigation techniques Evaluate impacts (Risk assessment) Are No Impacts Acceptable? Yes Final mine design ISO 14000 EMS
Initiating Events Initiating Consequence Event One to many Combination ? Choice of outcome
Initiating Events One to Many Initiating Consequence Event Dust Noise Blast Ground Vibration Air Concussion ?
Initiating Events Combination Initiating Consequence Event Clear land surface Surface erosion Rainfall ?
Initiating Events Choice of Outcome Initiating Consequence Event Contain & pick up ? Wash Fuel away Spill Do nothing ?
Cascading Initiating Events Consequence Consequence Initiating Initiating Event Event Blast Increase fractures Ground Vibrations Rock fall ?
Cascading Initiating Events Consequence Consequence Initiating Consequence Initiating Event Initiating Event Event Blasting Increase fractures Vibration Rock falls G.W. Pollution ? Fuel spill Wash away
Initiating Events - Examples Human • Mining o Drilling o Blasting o Excavating o Dewatering o In-pit transportation o Fuel spills • Processing o Crushing o Screening o Washing o Stockpiling • Transportation to market • Reclamation
Initiating Events - Examples Natural • Climate / weather o Droughts o Heavy rain events o Precipitation during critical periods • Ground-water level changes • Thresholds o River downcutting • Karstification • Tectonics
Hierarchical Systems Analysis Mining method Identify Initiating Events How system changed by mining (Consequences) How system will respond Citizen to changes (Analysis) input Consider mitigation techniques Evaluate impacts (Risk assessment) Are No Impacts Acceptable? Yes Final mine design ISO 14000 EMS
Consequence Analysis • Consequences can be analyzed and expressed in quantitative or qualitative terms including: o Timing of the impact o Duration of the impact o Range of the impact o Magnitude of the impact.
Potential Consequences – Example Aquifer characteristics Conduit & diffuse flow High storage Variable Recharge One of Many Possible Outcomes
Potential Consequences – Example Excavation In Unsaturated Zone Quarrying in the unsaturated zone in karst terrain is likely to result in relatively local impacts . One of Many Possible Outcomes
Potential Consequences – Example Excavation In Unsaturated Zone Erosion, sedimentation Dynamic (geologic) Reduction of No filter for Removal of protective cap rock Destruction of habitat Engineering Impacts Visual Blasting - noise, dust, contaminated surface water ground-water storage impacts and unsaturated material vibrations Contaminated spring discharge Reduction of porosity Filling of small voids Alteration of Decrease in Reduction of biotic and ground-water bacterial action biodiversity environment flow One of Many Possible Outcomes
Potential Consequences – Example Shallow Excavation In Saturated Zone Redefine drainage divide Wetland & All engineering Spring habitat impacts plus: desiccation destruction Destroy karst Alter mesoscale and Change pH Extraction inhabitants Intercept Dewater Flood microscale habitat Sinkhole collapse Karstification Loss of buoyancy conduit quarry mine Lower water table Alter ground-water flow One of Many Possible Outcomes
Potential Consequences – Example Deep Excavation In Saturated Zone All impacts of previous SZ quarry scenario plus… Change to losing Further habitat degradation stream Karstification Broad regional impacts to g.w. flow One of Many Possible Outcomes
Potential Consequences – Example Deep Excavation In Saturated Zone - Reclamation Redefine drainage divide Susceptible to Exceed (fail to meet) surface water Create Susceptible to previous level contamination Raise new springs ground water Fill quarry Rejuvenate water table contamination with springs water Modify ground-water flow paths One of Many Possible Outcomes
Potential Consequences – Example Deep Excavation In Saturated Zone Different Climate or Conductivity Another Possible Outcome
Hierarchical Systems Analysis Mining method Identify Initiating Events How system changed by mining (Consequences) How system will Citizen respond to changes input Consider mitigation techniques Evaluate impacts (Risk assessment) Are No Impacts Acceptable? Yes Final mine design ISO 14000 EMS
Summary • We use large amounts of carbonate rocks. • There is no substitute material for the majority of uses. • We need to continue to mine carbonate rocks. • Aggregate mining will create environmental impacts .
Summary • Numerous possible impacts • Cascading impacts • Numerous possible outcomes • Dependent on natural and human conditions. GOAL: Provide a continuing supply of high quality carbonate rocks while sustaining environmental quality.
Hierarchical Systems Analysis One method to accomplish this goal.
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