DRC-2013-005143 - 0901a068804ae213

Figure 1. Alternative tailings cell cover design.
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Technical Workshop on Revised Infiltration and Con~aminant Transport
Modeling Report and. Rev. 5.0 Reclamation Plan
DRC-2014-005143
White Mesa Mill Site, ~landing, Utah
Energy Fuels Resources (USA) Inc.
Utah Division of Radiation Control
MWH Americas, Inc.
U RS Corporation·
April 30, 2013
Denver, Colorado
AGENDA
9:00 ~ 9:15 AM : WELCOME & INTRODUCTIONS
9:15AM-11:00 AM : Revised ICTM Report Discussion
11:00 AM-11:15 AM: .. ~reak
11:15 AM-11:45 AM : Revised ICTM Report Discussion
11:45 AM-12:00 PM : Additional Questions?
12:00 PM - 1 :00 PM : Working Lunch/Revised ICTM Report Discussion
1:00 PM -2:00 PM : Revised ICTM Report Discussion (concluded)
.
2:00PM.-2:10PM : Break
2:10PM:-4:45PM: Revised Reclamation Plan Discussion
4:45 PM -5:00 PM : Additional Questions?
POWER INFRASTRUCTURE FEDERAL INDUSTRIAL & COMMERCIAL ~fit:
2
Revised ICTM Report
Infiltration and· Contaminant Transport Model Report
(Revised March 201 0)
POWER INFRASTRUCTURE FEDERAL INDUSTRIAL & COMMERCIAL -t;ff:
3
Revised ICTM Report
A. Key ICTM-Related Issues/Concerns for Proposed ET Cover
Design
'-){.. • Constructability of proposed very flat topslopes of cover is uncertain (RecP/an Session-
Afternoon)
• No cobble/very coarse-grained biointrusion layer => biointrusion impacts to cover
• No capillary break/barrier layer => Adequacy of moisture storage capacity in cover under
possibly wetter future climate conditions?
-;; • Infiltration sensitivity analyses--Bound range of possible future climate conditions
• Several uncertainties regarding effectiveness/success of proposed cover vegetation
• Impacts of differential settlement /potential for tailings liquefaction and effeCts on cover (slope
flattening/slope reversal; cracking of most compacted, most clayey soil component of cover)
. not yet adequately analyzed (RecP/an Session -Afternoon)
• Contaminant Transport Modeling
;;... Some input parameters used in contaminant transport model are uncertain/appear to
be in error
;;... Certain modeling assumptions need better justification
-". ...
POWER INFRASTRUCTURE FEDERAL INDUSTRIAL & COMMERCIAL ~¥"",.
4
Revised ICTM Report
B. Other Issues Related to Cover Design I Cover Performance
• More detailed site-specific differential settlement analyses reflecting spatially variable
tailings characteristics are needed (RecP/an Session-Afternoon)
• Input parameters used in differential settlement and liquefaction analyses need to be based
on site-specific tailings data not literature values (RecP/an Session-Afternoon)
• Owing to uncertainties associated with the future performance of the currently proposed ET
cover design, construction of Cover Test Pad(s) and completion of a comprehensive Test
Pad monitoring program are warranted prior to full-scale cover construction to validate
several design assumptions and model predictions (RecP/an Session -Afternoon)
~ ...
POWER INFRASTRUCTURE FEDERAL INDUSTRIAL & COMMERCIAL ,.,.,.. ..
5
Revised ICTM Report
Final Cover Design Issues and Considerations (con't)
• Uncertainties: infiltration and contaminant transport modeling results
• Address full -range of potential climate conditions during 200-1 ,000-year long post-
closure period
• Moisture storage capacity of monolithic cover adequate? (no capillary break)
• Long-term cover performance -Nearly flat topslope inclinations proposed; effects of
long-term cover degradation on long-term performance: biointrusion damage (no
biobarrier) to cover; permissible maximum infiltration threshold?
• Tailings dewatering rates/effectiveness, consolidation rates (esp. Cells 2 & 3)
• Effects of differential settlement of tailings on cap integrity/slope reversal
• Long-term leakage rates through degraded cell liners (esp. Cells 2 and 3) =>
Potential for groundwater contamination ( CLI.t. 1, 1-.; "'')
6
Final Cover Design Issues and Considerations {concl.)
Revised Reclamation Plan
• Same issues as for Revised ICTM Report (infiltration and contaminant
transport; climate variability affects, water-holding capacity of cover, etc.)
~ • , Long-term cover performance -Flat topslope inclinations; effects of long-term
cover degradation on long-term performance: biointrusion damage (no
biobarrier); permissible infiltration threshold value?
~ • Tailings dewatering times & effectiveness, consolidation rates (Cells 2 & 3)
• Effects of differential settlement of tailings on cap integrity; potential for cover
topslope flattening/slope reversal
~ • Adequacy of surety (post-closure maintenance, multiple revegetation
campaigns?, herbicide applications?, other cover repairs required during
post-closure period?)
7
Constructability and CQAICQC for Proposed ET Cover
Constructability of. Proposed ET Cover Design
• Constructability of proposed very flat topslopes of cover is uncertain
• Impacts of differential settlement on cover (slope flattening/slope reversal,
cracking of compacted more clayey soils) not yet adequately analyz~d
CQA/CQC Plan-GPS/earth terrain modeling computer-.based
equipment tracking system (e.g., CAES) not discussed. CAES
can be used to:
• Verify as-built over layer thicknesses
• Verify layer/lift compaction levels
• Verify adherence to specified final lines and grades
-#.-.
POWER INFRASTRUCTURE FEDERAL INDUSTRIAl & COMMERCIAL ~.,.... ..
8
Ex. 1 Crescent Junction, UT Uranium Tailings Repository
{2°/o topslopes)
L = Lenglh In l'8et
S • Slope
Qpmp • DiSCharge per foot for lhe PMP rainfall
/ 'I
1
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, ..... , ,,
---';· ,;,_
N
• 4.46'
~ \ Scour= O.BT '-8'Hx!O'W
Berm (Typ)
.q_,.
POWER INFRASTRUCTURE FEDERAL INDUSTRIAL & COMMERCIAL ~.,.. ..
9
Ex.1 (con't) Cover Detail -Crescent Junction, UT
Repository Cover
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.. (-..1herwd Manco. Shale) --·
(v N.)
'---,_fXXX:S_;_xz;~xxx~xxs.:
UMTRA COVER DESIGN
'4
POWER INFRASTRUCTURE FEDERAL INDUSTRIAL & COMMERCIAL -4tf':
10
Ex. 2 Monticello, UT Uranium Mill Tailings Repository
(5% topslopes)
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t I /.I II "'
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11
Ex. 2 (con't) Cover Detail -Monticello, UT Repository
Cover
-Q)
C)
c:
0 c..
(/) -.....
~E co (.) __.(")
Q)<D
C)~ co .....
0 en .....
Q)
~ co ~
4 1 .0 em _.,, ..
30.5 em
• \ '-19 .. .... ·~ .... -... . .. . . . . . . ., .. . "' 30 5 em • • • .. .. • • •• • • • } .\.: • ., .. . ., -.. ·--~ . . . . . . . . . . ' . . .. --.. . . . .. . .......
• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 38 0 em . • • • • • • • • •. • • • • • ·~ ·.· '' ............. . • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • •
Vegetation (T of ET)
Gravel Admixture
in Upper 20 em
Topsoil
Growth Medium and
Frost Protection
(Fine-Grained Soil)
Animal Intrusion Layer
(Cobbles Filled w/ Soil)
Fine-Grained Soil
Geotextile Separator
Capillary Barrier
(Coarse Sand)
POWER INFRASTRUCTURE FEDERAL INDUSTRIAL & COMMERCIAL -t:flf:
12
Ex. 3 Proposed Conceptual Cover Design - U Tailings
Cell in Colorado
EXPLANATION
~
r::::J
Rock Blanket. 1.0 ft, ove< Beddir,g Layer
v~ Cover. -4.011.
lndudlng 0.5 it Rock Mulctt
Capillary Broek, 0.511
Blo-ln1ruoion Layer. 0.5 II
Radon Barrier. 0.9 to 5. 7 II
Geosyn1hetlc Uner, 0.03 II
~ lotlorimCover.2.011
L=:J Sands TaiUngs. 0..0 to 5.011
~ SlimesTalUngs, O.Oto10.011
; • • Sends TeiUr,gs · •
NOTES:
(1) ORIGINAL TAILING SURFACE IS THE ESTIMATED FINAL SURFACE OF TAILINGS AT
CESSATION OF TAILING CELL OPERATION (GOLDER, 2008b).
..,_.....,...... ......... _,.,.........,,...,._.,.., ,_MIWI
~-........ cl-......,lo!Hrll,_,_.,.... ..............,---..!.., .................... ........ 6 0 2.6 l fl _.....,.,..._....,..---. ................. .. _...,,.....,._........__ .. ,.,.. ... _.,..,. ...,......,......,.,. ............. ___ .... ac.a.L.E.:1~•A-.,....,..,.,. .. ~ .... ~n.--~---.......... __.... ...... .-...:....-illll ........ ., ... ,..., .................... ~
POWER INFRASTRUCTURE FEDERAl. INDUSTRIAL & COMMERCIAL ~flf:
13
·-
·--·-~
I -·-ca ..... Cl) c
L.
Cl) > 0
0
-c
Cl)
tn
0 c.
0 L.
D..
c: 0 0-c ~ca L. Mo
><o wo
~~ ~~t >l!i
( A
., a Q
! ~ ::J
f 'I! i J ~ .... J j J
' I I '
' I I J ' I
. I i I I I !
' . I I
Ex. 4. ET Cover System Design-Rocky Mountain
Arsenal, Colorado
Diverse mixture of native plants;;::;::-. -=··"'.-: ...... :-. --·
-'~"'*' POWER INFRASTRUCTURE FEDERAL INDUSTRIAl & COMMERCIAl ,.,.....,
15
ET Cover DesignNegetation Establishment
Considerations
Ex: ET Cover Design, Rocky Mountain Arsenal, Colorado:
"Development of the seed mix for the cover vegetation involved considerations of the
following types of plants:
-
~ Those with a shallow root system that will intercept some of the rain before it impacts the
ground surface, ... dissipate wind energy, ... and enhance the soil surface's resistance to water
and wind erosion;
~ Those with a complementary deep root system that would help increase
evapotranspiration; ...
~ T~ll grass species to help deter invasion by prairie dogs ... "
Williams, eta/. 2011 "Covering It All," Civil Engineering, Jan. 2011
Ex: Monticello, Utah Repository Cover:
"[Vegetative soil portion of cover] designed to be sustainable over the long term and to mimic the
ecology of sagebrush-wheatgrass communities growing in deep soil."
"Vegetation, particularly deep-rooted shrubs, plays a key functional role in the long-term
performance."
-'~"'* POWER INFRASTRUCTURE FEDERAL INDUSTRIAL & COMMERCIAL ,r .,.
16
ET Cover DesignNegetation Establishment
Considerations (concluded)
Example Case Study: Moab, Utah Mill Site and Repository Cover
Revegetation Plan
• Perform vegetation survey to identify any distinct areas of different cover and species
composition in vicinity/surrounding area
• Determine optimal timing for seeding(s) and planting(s)
• Define watering schedule and watering methods (update plan annually?)
• Provide weed control plan (with area-specific recommendations) and schedule ~
• Annual assessments of vegetation coverage and soil nutrients after first seeding and t} ~:
planting (For -2-3 years for grasses; For -5 to 7 years for forbs and shrubs?) 411
• Need to adjust watering and weed control schedules annually based on observed )
revegetation results?
• Need for raising native seedlings on-site?
• Perform fauna studies?
17
Cover Revegetation Goals vs. Results-Ex.: Monticello
ET Cover
Monticello, Utah Tailings Repository Cover Revegetation Program
Activities & Chronology
• 2000-Seeded and planted: mixture of grasses, forbs, and shrubs
• 400 live sagebrush shrubs installed per acre
• 2001 -2003-predominantly weedy species present
• Cover reseeded in 2005 with bottlebrush squirreltail perennial grass species (to
compete vs. continued cheatgrass/ goatgrass growth) and several shrub species
• 100 of 400 originally planted shrub plants still living in 2007 *
• Live rabbitbrush planted on cover in 2007 using seedlings grown from both local
plants and commercial seed => -15 % of local seedlings survived vs. -8 % of
commercial seedlings by 2008 *
• Herbicides applied in 2011
* Possible causes of plant loss: 11Seed predation by voles, drought conditions, transplant shock,
timing of planting vs. rainfall events, heat stress, water stress, ... "
18
Cover Revegetation Goals vs. Results-Ex.: Monticello
Cover (concluded)
Monticello, Utah Tailings .Repository Cover Vegetation Results
• Prescribed shrub diversity and density goals have not yet been achieved
• "Lack of soil structural development and its possible effects on water movement may
be contributing to poor shrub establishment. ..
• Successful design, performance monitoring, and maintenance of ET covers require
measurement of soil edaphic properties (properties that influence vegetation
establishment and growth), as well as measurement of soil hydraulic properties ...
• Continuous monitoring over several years may be necessary to understand how
covers are influenced by fluctuations in climate and other environmental factors ...
• Poor establishment of deep-rooted shrubs on the Monticello cover likely caused water
accumulation lower in the [caisson test cell] cover profile after an exceptionally wet
Winter and Spring 2004-2005 and hence, caused a subsequent decrease in the
available water storage capacity in the profile ... "
.,..,
POWER INFRASTRUCTURE FEDERAL INDUSTRIAL & COMMERCIAL ~.,.....,.
19
l
Revegetation Criteria vs. Monitoring Results f9r
Monticello Cover
5.5% 0.14 28
12.2% 0.23 139
22.5% 0.27 88
31.3% 0.47 96
37.7% 0.61 142
20
Revegetation Results vs. Goals (con't)-Ex.: Monticello,
ET Cover
1 ooo,... -se T - - - - - - - - - - - - - - - - - - - - -t 1.0 900~ 45 ~ Revegetation Goal < • • 1-0.9
OJ 800 -40 t-- - - - - - -- - -- - - - ---• ---~ 0.8 ....
u 700 ;35 0.7 ~ ct > ~600 830 "'C
0.6 ..5 .C:' ....,
~ ·c;; 500 ~25 0.5 ~ t: u I ct ~ 400 ;20 0.4 ~ . .g 300 a.. Q) 15 0.3 ..J ....
~ 200 10 0.2
100 5 0.1
0 0 0
2001 2002 2003 2004 2005 2006 2007
21
Other Factors That Could Affect Cover Vegetation Growth
(e.g., Organic Matter 0/o, Extractable Potassium, Nitrogen °/o)
w1~-~.~ -,' ~JS-~~w~ '
60 120 ., lltolG 1 ~floe$ efR.
\\~-to
·'~k~ ·l
~S~\
~?
POWER INFRASTRUCTURE FEDERAL INDUSTRIAL & COMMERCIAL ~fill:
22
Other Factors That Could Affect Cover Vegetation Growth (e.g.,
Organic Matter%, Extractable Potassium, Nitrogen °/o (con't)
11 to 36 129 to 162 in upper 2ft (DOE
2007)
POWER INFRASTRUCTURE FEDERAL INDUSTRIAL & COMMERCIAl -t:ff:
23
Other Factors That Could Affect Cover Vegetation Growth (e.g.,
CaC03 Content; Exchangeable Sodium o/o (ESP}/SARs} (concl.}
White Mesa Uranium Project Environmental Report 1978:
Blanding Soil Series (White Mesa site): " 'C' horizon soils are calcareous"
11Subsoil sodium levels as ESP range up to -12.5 % in some areas [limited on.;.
site testing done] ... close to upper limit of acceptability for use in reclamation
k " war ...
Soils with > 10% CaC03 Content by Weight
Soils with < 10% CaC03 Content by Weight
Dwyer et a/. 2007, Cover System Design
Guidance and Requirements Document
24
Evaluation of Potential Flow Through Tailings Cell Liners
• Consider uncertainties associated with longevity of, and progressive
degradation behavior geomembrane liners (e.g., PVC liners in Cells 2 and 3 both
~ 30 years old) (assume "pessimistic" liner conditions, i.e., high end of assumed
range of defect frequencies and cracks/tears, etc. in liners?)
• Consider all potential contact conditions and PVC defect types
~ Poor contact vs. good contact
~ Consider circular and linear (e.g., seam failures, tears, cracks) defects?
• Consider variable thickness and permeabilities of recompacted Dakota
Sandstone underlayer materials
~ (6 in. thick vs. "thick composite liner" as discussed in Foose et al. 2001)
~ Assume broader range of Ks values for underlayer materials (sensitivity analysis)
to account for uncertainties (no data)
• Justify use of most appropriate leakage equation(s): Giraud et. al 1997 vs. Foose
et al. 2001 vs. Rowe 1998
-~~
POWER INFRASTRUCTURE FEDERAL INDUSTRIAL & COMMERCIAL ,.,... ..
25
Travel Times for Leachate Released from Tailings Cells
• Vertical Travel Times for Leachate to Reach Perched Water
);;> Darcy's Law calculations (established "benchmark" methodology)
V= q/ne = ( -K dh/dz)/ne
);;> Determine range of estimated travel times based on "best estimate_d" and most
conservative estimated values of hydraulic conductivity and ne of geologic
materials for location( s) considered
);;> Compare values of ne used to recommended literature "default" values (e.g., 10
%; NRC Final SRP, Title I UMTRCA, Rev. 1 (1993) or use values of ne derived
from site-specific data
);;> Account for potential influence of fractures &/or other heterogeneities that may
exist in the formation through vadose zone column
);;> Consider location(s) where vadose zone thickness is at a minimum
);;> Use log-normal frequency distribution for hydraulic conductivity values (?)
26
Tailings Cells -"Bathtubbing" Analyses
• Address uncertainties associated with the progressive degradation behavior of
geomembrane liners {e.g., PVC) based on available published information
{assume "optimistic" liner conditions. i.e., low end of assumed range of defect
frequencies and no cracks in liners?)
• Consider reasonably worst-case infiltration conditions in the analyses
~ Wetter climate condition
~ Degraded cover condition
~ Flattened tops lope (depending on approved settlement analysis results)
~ Assume minimal to no vegetation in cover ?
• Evaluate effects of infiltration through cover sideslope areas on bathtubbing
potential or demonstrate lack of detrimental impacts on bathtubbing
POWER INFRASTRUCTURE FEDERAL INDUSTRIAL & COMMERCIAL -ttft:
27
Revised ICTM Report
Contaminant Transport Modeling -Richard Henry, Principal
Geochemist, URS Corporation, Denver, CO (1-303-796-3978)
[e-mail]
David Edwards, Utah Division of Radiation Control
~ HFO and ANP term statistics
~ Bedrock bulk density term
~ Initial soil water pressure heads vs. recharge
~ Source term concentration statistics
~ Revise sensitivity analyses and report
28
I I
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Revision 5.0 Reclamation Plan (September 2011)
Summary of Key Issues/Concerns: Revised Reclamation Plan
• Constructability of proposed very flat topslopes of cover is uncertain
• No cobble/very coarse-grained biointrusion layer included in cover
• · No capillary break layer included in cover (moisture storage capacity)
• Tailings dewatering times & rates, consolidation rates (Cells 2 & 3)
• CQAICQC Plan-Use of GPS/earth terrain modeling computer-based
equipment tracking system is not-addressed (e.g., CAES):
~ Verify conformance to specified final cover lines and grades
~ Control and verify as-built cover layer component thicknesses
~ Verify layer/lift compaction levels
POWER INFRASTRUCTURE FEDERAL INDUSTRIAL & COMMERCIAL ~f/f:
31
Revision 5.0 Reclamation Plan (September 2011)
Summary of Key Issues/Concerns: Reclamation Plan (Con't)
• lmpa.cts of differential settlement on cover (slope flattening/slope
reversal, cracking of compacted more clayey soils) not yet adequately
analyzed
• Input parameters used in differential settlement and liquefaction
analyses should be based on site-specific tailings data vs. literature
values or data from other tailings piles
• Additional specific issues regarding the current differential settlement
and liquefaction analyses (further discussed below)
• Need for construction -of Cover Test Pad and completion of a
comprehensive Test Pad Monitoring Program prior to full-scale cover
construction to validate several design assumptions and corroborate
model predictions
32
.....
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Revision 5.0 Reclamation Plan (September 2011)
Settlement Issues
• Tailings assumed to be same material in all cells and throqghout each
cell
• Properties from very limited number of samples from Cell 2:
1977 (four samples) and 1999 (six samples)
• No variation in properties to account for sand-rich areas and/or slime
zones or for placement variation (wet slurry vs. thickened)
~~
POWER INFRASTRUCTURE FEDERAL INDUSTRIAL & COMMERCIAL ~.,....~
34
Revision 5.0 Reclamation Plan (September 2011)
...
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35
Revision 5.0 Reclamation Plan (September 2011)
Settlement Issues
• Use of Average Cc to estimate rate of consolidation diminishes effects
of primary consolidation observed at Points 2W1, 2W2, 2W3, 2W4, and
2W3-S
• Cc used in settlement calculations:
Minimum = 0.02 Maximum = 1.30 Average = 0.39
• Cc for Points 2W1, 2W2, 2W3, 2W4, and 2W3-S:
Minimum = 0.83 Maximum = 1.30 Average = 1.00
• Cc for settlement points in Other Cells :
Minimum = 0.02 Maximum = 0.56 Average = 0.15
.q""*'
POWER INFRASTRUCTURE FEDERAL INDUSTRIAL & COMMERCIAL ~.,... ..
36
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(lfl vo,, .... ""~
Revision 5.0 Reclamation Plan {September 2011)
Settlement Issues
• Amount and rate of settlement based on maximum tailings thickness in
each cell
• Consideration of variations in tailings thickness or water levels not
clear:
~ Cell 2 shows tailings thickness varies: 15 feet to 28.5 feet thick with three
lowest values 2W1 , 2W2, and 2W3
• Consideration of variations in drainage lengths and hydraulic
conductivity along different drainage paths not clear
• Consideration for different dewatering times due to one type of drain
system for Cells 2 and 3 and a different type of drain system for Cells
4A and 48 not clear
• Monitoring water levels in tailings not performed to confirm assumptions
or validate models
38
Revision 5.0 Reclamation Plan (September 2011)
Differential Settlement
"Additional settlement due to the construction of the final cover is estimated
to be on the order of 5 to 6 inches. The estimated amount of additional
settlement is sufficiently low such that ponding is not expected with a cover
slope of 0. 5 percent."
However,
• Use of average values masks effects of variations in magnitudes
and rates of settlements
• Consideration of variability tailings (properties, thickness, etc., as
discussed above) not clear
• Impacts on cover (slope flattening/slope reversal, cracking of
most compacted more clayey soil layer not adequately analyzed
POWER INFRASTRUCTURE FEDERAL INDUSTRIAL & COMMERCIAL -tfft:
39
Revision 5.0 Reclamation Plan (September 2011)
g
c ~ E ~ "' Q; "' "' 0 ....
0.0
1.0
2.0
\ ·· ..
\ \
\ \ --+-------
0
\
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Year$$ince LO<ld Placed
12
0%
10%
20%
30%
Total Settlemen: Mer
Dewatering. w•n Cc.
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Dew3tering. Ave Cc
-Total Settlement tJter
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50% ~
c 8
60%
70%
80%
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- -Rate of Conwhda:ion. A'fe C\'
---Rate o1 Ccnl.Ohda!icn, Ma• C•
Note: Settlement amounts shown are for indrllldU:JI
lo3dmgs, and are not cumulative.
-",..
POWER INFRASTRUCTURE FEDERAL INDUSTRIAL & COMMERCIAL ~'f"""..,
40
Revision 5.0 Reclamation Plan (September 2011)
Liqu~faction Issues
• Analyses based on assumed N-value -no in-situ characterization of
tailings and tailings assum~d to be consistent in all cells
• Assumed N-value (N=2) correlated with shear wave velocity, which is
correlated with settlements
• Consideration of variations in N-values not clear
• Consideration of variations in tailings (e.g., sand-rich zones,
amplification from silty/clayey zones) not clear
• Consideration of differential settlements and affect on cover grade and
integrity not clear
• Settlements calculated for "unsaturated zone" but monitoring water
levels in tailings not performed to confirm assumptions or validate
models
POWER INFRASTRUCTURE FEDERAL INDUSTRIAL & COMMERCIAL -tfff:
41
Revision 5.0 Reclamation Plan (September 2011)
Cover Test Pad and Test Pad Monitoring Program
Several Uncertainties Related to ET Cover: Extremely low natural organic matter content, low
extractable potassium, and low total nitrogen in on-site soils; Uncertainties regarding cover
vegetation success and characteristics ; Magnitude & duration of changes in future climate
conditions; Consequences of biointrusion; Impacts of future flattening /slope reversal of
tops/opes on infiltration
• Test Pad Design and Construction
};> Include Test Pad Lysimeter (EPA ACAP design)?-Ex's: Monticello, UT Test Cover
Caisson; Grand Junction, CO UMTRA Disposal Site Field Test Cover
};> Mimic full-scale ET cover construction processes
• Cover Materials Characterization I Test Pad Monitoring
};> Collect/test undisturbed block samples ( > 12-inch diameter) -ASTM D 7015
};> Monitor precipitation, runoff, soil water storage and percolation over time
};> Evaluate/test edaphic properties in Test Pad cover soils over time
};> Use natural analogs (sites with similar soils; consider vegetation characteristics)
42
Rev 5.0 Reclamation Plan (Sept. 2011)
Summary of Key Issues/Concerns: Reclamation Plan (con't)
Seismic; Hazard Characterization -Ivan Wong, Manager, Seismic
Hazards Group, URS Corporation, Oakland, CA(1-510-874-3014)
[e-mail]
• What seismic source model will be used?
• What ground motion prediction models will be used?
• How will site effects be addressed?
• How will the shear-wave velocity profile be developed for the
site?
POWER INFRASTRUCTURE FEDERAL INDUSTRIAl. & COMMERCIAL -t:f'f:
43
Rev 5.0 Reclamation Plan (Sept. 2011)
Additional Questions? -
Revised Reclamation Plan
POWER INFRASTRUCTURE FEDERAL INDUSTRIAL & COMMERCIAL -t:fll:
44
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