Mining R&R Matthew Gloe, Christian Bongard, James Brown Dr. W. Lee Daniels, Dr. Robert Grisso

This is Where Your Power Comes From

Consequences of Coal Besides the well known air pollution, there are large problems caused by coal that doesn’t even make it to market. Impurities that come from coal processing plants are placed in large waste piles (Gob piles), these account for 5% of disturbed mine lands. Gob piles are scattered throughout Virginia, each having potential to produce strong acid runoff.

How can we fix these problems? Upon completion of mining, reclamation of these waste piles is much more challenging than the actual mined area. To remediate and reclaim these sites, a comprehensive plan and design must be devised and implemented.

Our Site Red River Coal Co. – Norton, VA Their coal waste pile encompasses more than 100 acres Current acid mine drainage treatment involves spending $100-$1000 a month on a sodium hydroxide drip, along with man hours for constant monitoring. Norton, VA Red River Coal Mine Site

What are our goals? Design a passive vertical flow wetland system to treat acid mine runoff and reduce costs; in compliance with SMCRA and the Clean Water Act Engineer a soil to cover and revegetate the coal waste pile. Schematic of a Vertical Flow Wetland System

Alternate Passive Treatment Systems

Common Design Processes All passive treatment systems rely on alkalinity production from dissolved carbonate or bicarbonate. 2H + + CO 3 2-  H 2 O + CO 2 H + + HCO 3 -  H 2 O + CO 2 Secondary processes vary between designs, to include heavy metal removal.

Wetland Design Org. Layer Limestone Layer

Non-Mn Acidity = Acidity * Mn AlkNet = (99.3*log (t r )) + (0.76*Fe) + (0.23*Non-Mn Acidity) Limestone Volume (m 3 ) = (0.227*Q*t r ) / Vv Adtl. Limestone Volume for loss (m 3 ) = (0.0249*Q*AlkNet) / x Where: Q = flow L/min t r = residence time in hours Vv = void volume of limestone layer by % x = CaCO 3 content by % Design Parameters

Wetland Calculations Fe = 3 mg/L Mn = 12 mg/L Acidity = mg/L as CaCO3 Influent flow = 190 L/min Safety margin ≈ 60 mg/L of alkalinity Initial Data and Assumptions: Total Calculated Limestone Volume = 454 m 3 At a limestone depth of 0.6 m (2 ft), wetland surface area equates to: 750 m 2 or (27 x 27 m)

Important Notes Wetland treats only the baseflow Stormwater runoff is not treated, as it has the lowest acid and metal concentrations. Excess volume of stormwater can damage the wetland system, settling ponds and bypass channels will be used to govern flow.

Wetland Location Preliminary Settling Pond To Secondary Pond

Cost Analysis for VFW Chemical Treatment ≈ $1000/month One time VFW construction cost of $60-75 per m 2 ($56,250 for a 750 m 2 VFW) 5 years of chemical treatment is equivalent to construction costs of VFW Our wetland has a design life of 20 years Maintenance costs may be needed for VFW

Plants and bacteria work for free; people and machines don't. Basically…

How can we get plants to grow on coal waste? Engineered Soil and Revegetation -Direct liming (acid buffer) -Introduction of topsoil (rooting layer, temperature buffer) -Or Add Lime-stablized Bio-solids

What SHOULD be Done! Environmentally, Scientifically, Logically, and most importantly Economically, biosolids should be utilized Lime stabilized biosolids are FREE! Reduces fertilizer needed, and growing time No negative health effects. Addition of wood waste improves C:N ratio

Why It’s NOT Done It looks like this! Local public perception of the idea is so revolting that coal companies don’t even consider it anymore, despite the benefits.

Cost Effectiveness Treatment Material ($/Mg) Application (Mg/ha) Seeding+Fertilizer ($/ha) Area Covered (ha) Total Cost ($) Lime-Stabilized Biosolids / Wood Waste ,300 Traditional (Lime) ,280

Major Obstacles Communication with contacts Industry standard is English units Wetland sizing… single or multiple? Maintenance costs Pricing inconsistencies

In conclusion… There is an obvious need for mining remediation and reclamation A VFS and an engineered soil utilizing biosolids will be the most effective solution for Red River Coal. Our final wetland CAD design is currently underway and will be completed shortly.

We are… Mining R&R Questions?