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CQA, Zero-Leak Liners, & the role of geosynthetics as an asset in mining.
Introduction
Geosynthetics in Mining Businesses
Asset Insurance
Policy Revenue
Production
Liner Systems as Assets
Successful Site Owners have
progressed from a “Necessary
Evil” mentality to an Asset Mentality
100 Acre Geomembrane installation will
cost approximately $2.5mm USD
Your perspective on your system will determine your decisions
and your decisions
determine your ROI
Maximizing Investments
Geosynthetic installations are
multi-purpose assets where
the Return on Investment is
intrinsically linked with asset
performance.
Design Considerations
Specific Function/Role
Specific Situation
Project Life Cycle
In order for any geosynthetics
project to achieve the
maximum ROI, there are six
main components that need
to be properly examined
Design
Material Selection
Installation
Construction Quality Control
(CQC)
Construction Quality
Assurance (CQA)
Post-installation Operations
Increased Quality = Increased ROI
Geosynthetics as Insurance
Insurance Policy These are not just liner systems! They are pre-paid insurance
policies that preserve revenues, protect profits and mitigate risk of environmental damages due to breeches of containment.
Goal Purchase best possible risk protection for the most reasonable amount of capital possible.
Cost of Failure Vs. Cost of Prevention
Cause of Failure Cost of Failure Cost of
Prevention
Prevention vs.
Repair Cost
Multiplier
Improper Design > $600,000USD $20,000USD 30
Poor Installation &
No CQA $1,300,000USD $15,000USD 87
Poor Design,
Installation & No
CQA
$21,000,000USD $40,000USD 525
Material Selection $23,000,000USD $10,000USD 2300
In a 2005 paper, entitled Geosynthetics Risk Management and Loss Control Program, Peggs
and Peggs investigate the cost of failure versus the cost of prevention of these failures, as well
as the component causing the failure.
Understanding
Leaks in
Mining
What Influences Leakage Rates?
Leak Rate Variables
Leachate head
Damage density
(holes/acre) Size, shape
Location
Geomembrane /Subgrade
contact
Subgrade Permeability
Leakage Calculations
•Basin 1: 1,200 feet L by 1,000 feet W by max depth of 23 feet; assume average depth of
11.5 feet
•Basin 2: 1,200 feet L by 1,000 feet W by max depth of 20.7 feet; assume average depth
•As estimated by a Professional Engineer based on standard leakage rate volumes
Length Width Area Head Leakage
inches inches sq inches sq feet feet cfs gpm gpd gpad
Basin 1
0.75 0.5 0.375 0.002604167 11.5 0.04 19.08 27,481 999
1 0.5 0.500 0.003472222 11.5 0.06 25.45 36,641 1,332
3 0.5 1.500 0.010416667 11.5 0.17 76.34 109,923 3,997
6 0.75 4.500 0.03125 11.5 0.51 229.01 329,768 11,992
12 0.5 6.000 0.041666667 11.5 0.68 305.34 439,691 15,989
2 4 8.000 0.055555556 11.5 0.91 407.12 586,254 21,318
10 1.5 15.000 0.104166667 11.5 1.70 763.35 1,099,227 39,972
Basin 2
15 0.05 0.750 0.005208333 10.4 0.08 36.30 52,267 1,901
2 0.5 1.000 0.006944444 10.4 0.11 48.40 69,689 2,534
Gold Concentrate
Leakage Rate
Mineral
Concentration/
Day
Mineral
Concentration/
Year
550 gal/acre/day 0.10 oz t 36.6 oz t
250 gal/acre/day 0.05 oz t 16.6 oz t
32 gal/acre/day 0.0058 oz t 2.1 oz t
Daily Gold Concentrate Potentially Leaching Through Geomembrane
Table shows the approximate mineral content that is potentially lost, on an acre-per-
day basis, at the ALR rates mentioned above for gold.
Assumes:
•Gold concentration of 1.5 ppm in pregnant leach solution
•Gold: $1,300 USD/ozt
Copper Concentrate
Daily Copper Concentrate Potentially Leaching Through Geomembrane
Table shows the approximate mineral content that is potentially lost, on an acre-per-
day basis, at the ALR rates mentioned above for copper.
Assumes:
•Copper concentration of 5,500 ppm in pregnant leach solution
(Thiel et al., 2005)
•Copper: $3.00 USD/Pound
Leakage Rate
Mineral
Concentration/
Day
Mineral
Concentration/
Year
550 gal/acre/day 25.2 lbs 9200 lbs
250 gal/acre/day 11.5 lbs 4182 lbs
32 gal/acre/day 1.5 lbs 548 lbs
Gold-10 Year Potential Loss
Over a 10-year life span increases in leakage rates even to industry acceptable
standard levels (ALR) can significantly impact a project’s ROI.
In almost all cases the cost of preventing these leaks is a very small fraction of the cost
of losing concentrate.
Other financial considerations for the reduction of leaks should include the cost of the
leaching agent that is lost, the environmental impact and any associated clean-up
costs, as well as repair and maintenance costs to the liner system.
Leakage Rate 50 Acres 100 Acres
550 gal/acre/day $23,790,000 $47,580,000
250 gal/acre/day $10,790,000 $21,580,000
32 gal/acre/day $1,365,000 $2,730,000
Asset
Management
Design
Project Goals
Firm: Maximize ROI
Contemporary Practices
Project Constructability
Customized Specs & Plans
Optimum design
value cannot be
understated!
Geosynthetics do
not have “Ease of
Exchange”
Construction Quality Assurance
CQA Inspects
Verify
Audits
Determine Quality
Documentation
Site owner’s eyes and ears!
Standard Vs. Palo Verde
According to studies by B. Forget, A.L. Rollin and T. Jacquelin, Leak rate goes from
averaging only 4 leaks per hectare (2.47 acres) with rigorous CQA to averaging 22 leaks
per hectare (2.47 acres) without CQA.
4 Leaks per
hectare
799
22 Leaks per
hectare
4391
Palo Verde
0
Project Size: 493 Acres
Value of No Leaks: 2A (117 acres)
•Floor Leak: 60 million gallons would need to be removed
•Full Capacity Leak: 780 million gallons of water would have to be
removed just to make one repair
Construction Quality Assurance
Smart ROI!
Days Hours Rate Cost
Tech 1 30 11 $80/h $26,400
Tech 2 30 11 $70/h $23,100
Tech 3 20 10 $70/h $14,000
Abigail Beck states: “Average hole size and frequency contributing to
leakage depends heavily on the skill of the liner installer and the skill of
the CQA agency.”
Approximate costs ($US) of adding CQA field technicians to the project
Free Quality
End Coupons Extrusion Destructs
On-site Testing
Planned Pre-Construction
Increase Panel Width
Reduce Repairs
Enforce Material
Availability
Not to exceed Failure Rates
QC & QA Work Stoppage Authority
Conclusion
“The most dangerous phrase in the language is
‘we’ve always done it this way’.”
Rear Admiral Grace Hopper
1. Understand your liner system is your asset
2. Make decisions based on an asset mentality
3. Control of quality always equals control of ROI
4. Invest time and energy into the design phase that
will actually translate into a better asset
5. Orchestrate the entire process to your benefit!
Glen W. Toepfer
President
CQA Solutions
Blog: Uncontained.CO
419-460-0846
GRACIAS.
