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Rural Landscape Workshop Surface Water Quality

Peabody Energy

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Surface Water

● Water Uses and Sources

● Factors Affecting Water Quality

● Water Quality

Standards ● Why

Maintaining Water Quality is Important

● Best

Management Practices

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Surface Water – Uses and Sources

● Uses Removal of sediments from affected runoff – Sediment Basins Removal of coal impurities (rock, sand, silt & clays) – Coal Washing Dust control Facilities & Equipment wash down Potable and facility water Stored water for fire protection

● Sources Affected area drainage collected in sediment

basins Surface impoundments for coal washing Recycling – from sediment basins, coal

washing, dust control, equipment & facilities washdown, gray water from facility uses and fire protection water

Groundwater wells

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Factors Affecting Water Quality

● Geology ● Residence Time ● Material - Water Contacts

Rejects Overburden Soils Spills Leaks Erosion

● Base Flow ● Seeps ● Overland Flow

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● Receiving Stream Ambient Conditions Upstream and Downstream

● Groundwater conditions ● Land Use

Abandoned Mine Lands Agriculture Industrial Dischargers

Factors Affecting Water Quality

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Factors Affecting Water Quality

● Overburden Characteristics Geology

o Rock Types o Mineral Content o Hardness o Chloride

Underclay Example: Marine Shale

o Can be source of salts resulting in elevated sodium and chloride.

o Special concern when receiving waters are sensitive to changes in salinity.

Mine Operations

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Factors Affecting Water Quality

● Sulfide minerals

FeS2

Low pH: increases solubility of metals Increase in SO4

● Carbonaceous & Marine Shales

Coal Chemistry

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Water Quality Standards

● 1982 EPA Study: Development Document for Effluent Limitations Guidelines and Standards for Coal Mine Point Source Category Coal Chemistry is well known. EPA Study looked at 129 toxic or priority pollutants. Study concluded if indicator parameters such as iron, manganese,

TSS, flow, and pH were within a specified range then other pollutants were also in a safe range.

● The fundamentals of coal chemistry have not changed since 1982.

2FeS2(s) + 7O2(g) + 2H2O(l) ? 2Fe2+(aq) + 4SO42-(aq) +

4H+(aq)

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Water Quality Standards

● Common Parameters Iron pH TSS Sulfate Chloride

● Tools for Characterizing Water Quality Geochemistry

o Major Ions o Trace Elements

Mass Balance Modeling

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Water Quality Standards

● Water Quality Standards: Foundation of Water Quality Based Pollution Control Program (USEPA)

● Define goals of water body designated uses. ● Water Quality Criteria to protect designated uses.

Numeric Narrative

● Antidegradation Policy

Protect existing uses

● General Policies Variances Mixing Zones

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Meeting Standards

● THE BUSINESS CASE

● Meeting Water Quality Standards is CRITICAL! Results of Exceeding Standards Include:

Compliance Violations Tort Liability Permit Delays Bond Release Issues Reserve Sterilization Reputational Issues Increased Costs Perpetual Treatment

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Meeting Standards

● Understand Operations and Water Quality Watershed parameters Types of materials Internal water circuits Shop areas Disturbed areas Stockpiles Placement of overburden and rejects Discharges

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Best Management Practices

● Develop Plan Define roles and responsibilities Prepare Emergency Procedures Develop Maintenance Schedule for BMPs Establish Monitoring and Closure Plans

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Best Management Practices

● Develop Plan Test sources of water. Identify source and quality of all sight waters. Divide site into clean and dirty water. Minimize size of dirty water areas (phasing) Combine dirty areas. Line dirty water ditches where appropriate. Adequately separate dirty water and clean water holding areas. Identify residence time issues.

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Best Management Practices

● Acid Materials BMP’s Drainage Control: Understand

Geology/Geochemistry of coal and overburden. (Acid Base Accounting).

Plan mining/reclamation activities to reduce exposure to acid producing materials

o Place acidic materials at or near bottom of the spoil.

o Place alkaline material on top of acidic materials.

o Compact coarse coal processing rejects.

o Keep surface fresh. o Staged basins

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Best Management Practices

● BMPs Refuse/Acid Mine Drainage Control Contemporaneous Reclamation

o Spoil Placement o Timely Grading (reduce surface area) o Soil Replacement (cutoff atmosphere) o Immediate revegetation

Water Management o Reduce surface ponding in overburden o Reduce concentrating dissolved solids

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Best Management Practices

● Pollution Control Measures Materials storage Containment Spills Leaks Regular inspection & maintenance

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Best Management Practices

● Runoff Controls Staging

o Clearing o Grubbing o Scalping o Reclamation

Inclines to Pit o Minimize length

Soil Stabilization o Re-vegetation o Mulching

Seal Boreholes o Prevent uncontrolled runoff into pit or underground mine.

Maintain Adequate Barriers o Between old underground works and active areas.

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Best Management Practices

● Erosion Control BMP’s Use of Vegetation

o Mulching o Seeding o Matting

Grass-lined Channel Riprap Check Dams Temporary Slope Drain Terraces Sediment Trap Straw Bales Silt Fences Weep Berms

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Best Management Practices

● Sediment Ponds Professional design with sufficient volume

for treatment & sediment storage Consider lining ponds where appropriate.

o Synthetic/Plastic liners. o Bentonite. o Minimizes seepage

Minimize impervious areas. o Reduces fast runoff.

Use minimum volume of water necessary in the process circuit.

Eliminate unnecessary ponds. Consider additional passive systems.

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Best Management Practices

● Stream Restoration Natural Stream Design Planning Riparian Zones Buffer Filters Structures Native Species

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Associated Studies

● 1979 EPA Study: Evaluation of the Performance Capability of Surface Mine Sediment Basins. Determined sediment basins are

the preferred option for removing surface water sediments.

Sediment basins are still the preferred sediment control measure.

EPA recently began requiring sediment basins for construction sites.

● NARM, Wyoming

Post Mine Water Study ● Vermillion Grove, Illinois

Trace Element Study ● Farmersburg, Indiana

Reconstructed Stream Study ● Southern Illinois Streams

Reconstructed Stream Study

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Wrap Up

● Understand Uses and Sources

● Understand how sight characteristics influence water quality.

Geology/Geochemistry

o Overburden o Coal

Operations o Mining Areas o Processing Areas

Surface Waters o Receiving Streams o Onsite Flow System

● Understand regulatory

requirements and options. ● Implement best practices.

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References

Castendyk, D.N. and Eary, L.E. (Eds.), 2009, Mine Pit Lakes Characteristics, Predictive Modeling, and Sustainability Volume 3, SME, Littleton CO.

Giller, P.S. and Malmqvist, B., 2003, The Biology of Streams and Rivers, Oxford

University Press, Oxford, UK. Hem, 1989, J.D., Study and Interpretation of the Chemical Characteristics of Natural

Waters, Third Edition, U.S. Geological Survey Water-Supply Paper 2254, United States Government Printing Office, Available online only @

http://pubs.usgs.gov/wsp/wsp2254/html/pdf.html Skousen,J. and Others, 1988. Handbook of Technologies For Avoidance and

Remediation of Acid Mine Drainage, The National Mine Land Reclamation Center, Morgantown, WV. Available online @

http://www.techtransfer.osmre.gov/NTTMainSite/Library/hbmanual/hbtechavoid/front.pdf Younger, P.L., Banwart, S.A, and Hedin, R.S., 2002, Mine Water Hydrology, Pollution,

Remediation, Kluwer Academic Publishers, Norwell, MA.