Transcript William C. Ehler, P.G., Project Manager Office of Surface Mining Appalachian Region, Federal Reclamation Program Pittsburgh, Pennsylvania 15220

William C. Ehler, P.G.,
Project Manager
Office of Surface Mining
Appalachian Region, Federal Reclamation Program
Pittsburgh, Pennsylvania 15220
“Blackdamp”
Usually associated with
communication of shallow
abandoned mine
atmosphere with surface
structures via old shafts &
entries
 12 – 15 % CO2 in
abandoned mine
atmosphere
 CO2 & Methane are
natural products of coal


% CO2 in Air
Increase in Respiration
0.03 ....................................... Normal Air & Respiration
0.05 ....................................... Slight Increase
0.5 ....................................... TLV-TWA (8-hr max by law)
2.0 ....................................... 50% more Respiration
3.0 ....................................... 100% more Respiration
TLV-STEL (max by law)
5.0 ....................................... 300%, Laborious Breathing
10.0 ....................................... Cannot be endured,
unconsciousness
Concentrations over 0.5% CO2 produce relative decrease in O2.
O2 - Percent
Effect
21% ..........................Normal Breathing
19.5% .......................Minimum Required by Law
17% ..........................Breathing Becomes Faster & Deeper
16% ..........................Pilot Light Extinguishes
16-13% .....................Dizziness, Rapid Pulse, Headache, etc.
9% ............................Unconsciousness
6% ............................Convulsions and Death
Data Set 1
Hudson Mine Gas Complaint
Carbon Dioxide
5
4
Data Set 2
Data Set 1
Data Set 3
CO2 Peak 15.1%
Average 5.5% over
18 hours
3.0% TLV-STEL
%
3
2
1
0.5% TLV-TWA (action level)
0
Date
Modifications to Hot Water Heater
by Home Owner to address
Blackdamp Problems
Base of Tank
Raised off of the
Floor
Fresh Air Inlet
Box Fan to
Exhaust Air
Low barometer
High CO2
Low O2
Isotopic ranges of natural gases are large in range,
specific, predictable, and capable of providing
diagnostic information on their source.
 Differences in isotopic mass lead to subtle but
significant differences in the behavior of an element
during natural processes (fractionation)

  13CO2 =
Rsample – Rstandard * 1000 (permil)
Sample
Brush Creek Shale
Kanawha Black Flint
Lower Kittanning
Underclay
Houchins Creek Shale
Middle Kittanning
Sandstone
Wadesville Sandstone
Valentine Limestone
Coal Refuse
(From processing
Kittanning seams)
Redstone Limestone
State
(Stratigraphy)
Pennsylvania
(Conemaugh)
West Virginia
(Kanawha)
Pennsylvania
(Allegheny)
Indiana
(Carbondale)
Pennsylvania
(Allegheny)
Pennsylvania
(Anthracite region)
Pennsylvania
Neutralization Potential
(tons/1000 tons)
% Sulfur
96.9
0.59
16.9
0.31
12.6
0.91
43.6
5.15
17.7
0.04
261
0.01
902
0.01
Pennsylvania
(Allegheny)
0.9
1.68
West Virginia
(Monongahela)
467
0.38
Bailey residence, Volant, Lawrence County 2006
 CO2 ambient levels up to 3.0% measured inside the
home
 Home was built on about 110 feet of mine spoil from
a large surface mine operation of the Brookville and
Kittanning seams of the Potsville Fm.
 Carbonate source identified as glacial till and the
spoil augmented with scrubber sludge
Bailey site
Older project sites
Un-mined land
Bailey Property

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


Cost: $23,000
Construction Period: 15 Days
Power: 350watts & Long-term Maintenance
Noise & Temperature differential in basement
Reduce CO2 to 0.08% except very low
Barometer
Popson residence, Fairchance,
Fayette County 2006
 CO2 ambient levels up to 6.3%, exceeded 25% in
foundation cracks
 The full basement, no windows and partially
finished.
 Mine 40-60 deep in Redstone Coal, Spoil associated
with a massive Limestone seam.
Vents
SSPP inlet location &
restored floor
Air inlets for SSPP & Air
Exchanger


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

Cost: $27,000
Construction Period: 20 Days
Problems with working around the partially
finished basement
Mine abandoned in interim period, almost did
not qualify for AML funds.
Problem may be area wide.
Hudson residence,
Velpen, Pike County 2008
 O2 levels depressed as low as 12% inside the home
 CO2 levels more than 25% measured in cracks and
holes in the foundation around the home
 Resulted in death of two family cats
 Low barometric pressure and heavy rains
Hudson
Property
Monitoring shows less severe in the summer
Modifications or replacement of the basement floor
would be required for mitigation.
 Sealing of the block walls would require replacing
much of the basement already finished and or deep
excavation around the perimeter of the home.
 USGS has been acquired by the INDNR to help
study and recommend solutions.


Problems are more extensive

Mostly recently abandoned surface mines

Must have carbonate materials and other conditions
to harbor the CO2.

Property owners, developers and local agencies are
unaware of the problem.

Sub-Slab Positive Pressure systems, Sealing
foundation

Foundation ventilation, French Drains may be
required

Air Exchangers may be required on worse case
situations.

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Trenching and drainage around property
Land Use / Building Code
Mine regulation

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How does topography and compaction of the mine
play to the problem?
Do we need to reconsider augmentation of the mine
spoil to neutralize AMD?
Should we continue to burden the homeowner with
mitigation systems?
Regulation Changes?
Is the problem hiding in your state?