Cost optimization has to identify the most common problems to the hydrogeological investigation as travel time and transport issues, seasonal restrictions, personal availability, protocols, etc. This post is focused on strategies and best practices for cost (& time) optimization, specially for hydrogeological investigation on mining projects.

1. Cost (& Time) Optimization
of Hydrogeological Studies
By:
Saul Montoya M.Sc.
March 2013

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This presentation is focused on:
Strategies and best practices for cost
(& time) optimization.
Specially for hydrogeological
investigation on mining projects

3. Mining Hydrogeology
Currently mining projects has to fulfill a series of
hydrogeological investigation along the mine life.
Increasing concern about the environmental
impacts.
Hydrogeological investigations and numerical
modeling has to simulate, prevent and remediate
the mining impact to groundwater system and
surface water courses.

4. Mining Hydrogeology
There is continuity on the hydrogeological
investigations. Results from the assessment from
one mine stage (feasibility) became an input for the
next stage.
Source: Australian Government, Department of Resources,
Energy and Tourism (2008)

5. Mining Hydrogeology
Impact on the groundwater flow from mining
facilities could be evaluated many times alongs the
different mining phases.
Many of these evaluation are done by different
consultant companies.
Sometimes two companies investigate the same
impact at the same time.
Challenge: Decrease the double effort!

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Das Ziel
(the objective)

7. Water Management in Mining
Water management in mining objectives are:
• Assess all relevant aspects relevant to water
extraction, treatment, use and preservation.
• Indentify all current and potential risks to natural
water bodies from the mining activity.
• Simulate and evaluate the impact from the mine
water use to the other water users.

8. Water Management in Mining
Water management plan characteristics:
• Water-quality and water-quantity integration.
• Incorporates site general hydrological conditions.
• Has a detailed plan with responsibles and
calendars.
• Plans with quantitative objectives rather than
subjective objective.
• Has reports, operation procedures, and manuals.
• It is dynamic, regularly rewieved and updated

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Main Hydrogeological
Investigation in Mining

10. Mine Project Development
• Baseline investigation on groundwater / surface
water flow regimes.
• Monitoring network design.
• Groundwater impact assessment (quality and
quantity) due to the mining project.
• Mine water supply evaluation.
• Pit inflows and mine drainage evaluation.
• Predictive simulation of groundwater flow regime
on mine closure.

11. Mine Life
• Water resources database management system
implementation.
• Surface water / groundwater monitoring system
upgrade.
• Pit inflow / mine drainage modeling update.
• Contaminant transport modeling from waste
dumps and tailings deposits.
• Upgrade of groundwater numerical models and
resimulation of project impact.
• Predictive simulation of groundwater flow regime
on mine closure.
• Rules for site potential contaminant release.

12. Mine Closure
• Water balance on closure conditions.
• Assessment of the pit lake flooding time, final
level and water quality.
• Review of contaminant transport modeling on
closure conditions (Validation / Optimization).
• Evaluation of natural attenuation on contaminant
transport evaluation.
• Design of remediation plans.

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Das dinge an sich (Kant)
The thing in itself

14. The thing in itself
Plan, plan and plan!

15. The thing in itself
“Begin with end in mind”
Habit 2 form the book “The 7 Habits Of Highly Effective
People” from Stephen R. Covey
Before spending hours in any task one has to
understand why the task is being conducted and
how it helps to meet the project need.

16. The thing in itself
For cost optimization, you have to do the minimum
required to effectively accomplish the goal you need
to reach.
In the end, it´s highly
about money, money, money!

17. The thing in itself
Take into consideration these Bottle-necks:
- Travel and transportation times
- Seasonal restrictions
- Personnel disponibility
- Problems with communities
- Security protocols, and many more…
Bottle-necks are simple to remove after they are
identified.

18. The thing in itself
Dont be too optimistic about your times and
budgets.
Once a contract is signed, it becomes very difficult
to change the hydrogeological study scope or to ask
for money and time.
Insufficient planning and failed attempts to
minimize costs led to effort duplication later on.

19. The thing in itself
"If anything can go wrong,
it will.“
Murphy's law

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First Step:
Conceptual Modeling

21. Conceptual Modeling
Conceptual modeling is the first step on the
hydrogeological investigations.
The conceptual model is the degree of
understanding of the groundwater flow regime with
the available information.
If the hydrogeological conceptual model (and the
geological conceptual model) are flawed everything
else is flawed – design of the groundwater flow
regime.

22. Conceptual Modeling
We can have a reasonable from a site and data with
good background on hydrogeology:

23. “Hydrical Eye”
What everybody see versus what a hydrogeologist see.
Cuenca, Manantiales
y Bofedales
Ancash
Springs
Wetlands
Precipitation as
Snow
Natural Drains
Fuente: Trekearth.com

24. Conceptual Modeling
Conceptual modeling is a tool. One have to build,
review and improve it.
A reasonable conceptual model from the beginning
help focus on what data are most critical.
All phases of the hydrogeological investigation will
update the conceptual model.

25. Conceptual Modeling
Conceptual model will optimise well locations and
inform the understanding of aquifer interactions.
It is good to use the results of previous studies a
basis for the investigation phases.
The conceptual model is then “translated” to the
numerical model.

26. Conceptual Modeling
Groundwater flow is spatially distributed, therefore
you should build you conceptual model with GIS
tools (If you dont want to mess around with a
bunch of maps and reports).
Save the trees!

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Einige Empfehlungen
(some recomendations)

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Field Investigation

29. Field Investigation
Seek for the opinion of a specialized group of
people early on the mine planning.
Coordinate geotechnical and hydrogeological
studies. Both tasks can collaborate on the drilling
and characterization efforts.

30. Field Investigation
Why dont you install a piezometer on every
geotechnical drilling?
It might be not suitable for groundwater quality
monitoring but is okay for water levels and
hydraulic tests.
Baseline soil chemistry chemistry can be done at
the same time too. This information is also very
important for mine closure to show original soils
quality versus post-operational phase chemistry.

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Monitoring Network

32. Monitoring Network
A minimum of 30 piezometers is required to have a
normal distribution of water heads. However a
mining proyect in its early stages has fewer points.
An optimized approach is to couple piezometric
data with baseflow gauging.
This is a recommedation from the common
practice: a monitoring network of 12 piezometers
(>30m) plus 5 baseflow measurements will be
enough to give a good understanding of the
groundwater flow regime.

33. Monitoring Network
Groundwater levels and baseflow variation. How is the correlation with depth
of installation.
Source: DCNR

34. Monitoring Network
However, the number of piezometers depends on
scale of the development and complexity of
groundwater regime.
Mining project / consultants in Perú usually budget
from 8 to 12 piezometers that is limited to
understand the groundwater flow regime. If
modellers ask for 30 there will be more chance to
get 18 points.
The bigger the water level / baseflow monitoring
network, the better understanding of the
groundwater flow regime.

35. Multilevel Piezometers
Multilevel piezometers can describe
different piezometric level with levels
at one location.
These piezometers can give useful
information about anisotrophy,
hydralic parameters and recharge
mechanisms.
Multilevel piezometer has not much
value without multilevel readings with
time (minimum one year). Source: Solinst

36. Multilevel Piezometers
Multilevel reading requiere a more
detailed numerical modeling with
transient calibration. Better
estimation of K, Sy and Ss.
If you plan to deliver a report in 6
months, it is better to use one level
piezometers.
Source: Solinst

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Field Sampling

38. Field Sampling
Do a lot of sampling on the early stages of your
hydrological investigation.
Analyze the spatial and temporal variability of
groundwater levels and quality.
Then optimize your piezometric network!

39. Field Sampling
Dynamic of
monitoring
networks

40. Field Sampling
Nobody has a university degree to:
• Sample groundwater levels.
• Measure groundwater ph, conductace and
temperature.
• Use a flow meter, or reading a water scale.
Hire local capacity!

41. Field Sampling

42. Field Sampling
There is balance in between the water level
sampling frecuency and error on the measurement.
The lower the cost, the higher the error.

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Pumping Tests

44. Pumping Tests
Usually one has to quote supervisors 24 hours, plus a
generator in backup.
High uncertainty on the results and interpretation if
pumping is interrupted.

45. Pumping Tests
Graphical interpretation of pumping test comes from the
70’s were computational power was scarce.
Software for pumping test
interpretation do not take
into account anysotropy,
incontinuos layering and
varying pumping schedule.

46. Pumping Tests
Pumping test interpretation with numerical modeling
gives you flexibility to:
• Turn on, turn off, increase / decrease pumping rates
several times as long as you record the pumping
schedule and rate.
• Only need a operator to fuel the generator.
… that decreases the cost of the pumping test!

47. Pumping Tests
Nowadays submersible pumps are more
slim.
2” submersible pumps can perform pumping
tests on 4” piezometers
… that increases the availability of the
pumping locations!

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Die Helden (The Heroes) :
Groundwater
Numerical Models

49. Numerical Modeling
Groundwater numerical models are not a “trendy”,
“stylish” or “fashionable” part of the hydrogeological
report.
Groundwater model are the best tools available to
understand the fate and transport of the groundwater
flow regime.
We have to see groundwater models as a management
tool.

50. Numerical Modeling
Determine the need for
numerical modeling.
Select the right code to fulfill
the investigation objectives.
Specify the level of detail of the
numerical model
Compile all relevant data before
detailed modeling.

51. Numerical Modeling
Numerical models need a good conceptual foundation.
Otherwise numerical model becomes a “black box”
bringing “rubbish” water head and concentrations that
looks great on maps and cross sections.

52. Numerical Modeling
Usual hydrogeological study secuence:
Optimized hydrogeological study secuence:
Data
Compilation
Field
Investigation
Data
Analysis
Numerical
Modeling
Impact
Evaluation
Data
Compilat
ion
Coarse
Numerical
Modeling
Field
Investig
ation
Data
Analysis
Fine
Numerical
Modeling
Impact
Evaluation

53. Numerical Modeling
Advantaje of the optimized hydrogeological study
secuence:
• Coarse numerical modeling strength the conceptual
modeling.
• More flexibility to identify “hotspots” in the area of
study.
• Optimization of the drilling program.
• More time for data analysis.

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Der Anschluss (The Continuity) on
Hydrogeological Studies

55. Continuity
When working with data these are the percetanjes of
time spent on related tasks:
Data compilation can be reduced to 15% if there is a
continuity on the staff related to the investigation and
the implementation of DBMS (Data Base Management
Systems).
… that means a time saving of 25% on the cabinet
tasks.
Data
Compilation
40%
Data
Analysis
20%
Numerical
Modeling
40%

56. Continuity
We have to assure the quality of the hydrogeological
studies.
Background knowledge is critical to supervise the work
of consultants, field monitoring staff and even reviewers.
Change of consultants only good practice when the
produced studies do not fit the regulatory official
requirements.
Never change of consultants without a good reason,
since there will be a “gap” on the data and the
conceptual model… that means more time consumed.

57. Continuity
For cost optimization, the consultant company that runs a
regional model should be the same the one in charge of the
local numerical modeling (tailings dam, pit).
Many consultant companies running modeling work on parallel
mostly turn on effort duplication, low comunication and
different approaches of the groundwater flow regime.
… but why?

58. Continuity
The Unknown
As we know,
There are known knowns.
There are things we know we know.
We also know
There are known unknowns.
That is to say
We know there are some things
We do not know.
But there are also unknown unknowns,
The ones we don't know
We don't know.
D.H. Rumsfeld, Feb. 12, 2002,
Department of Defense news briefing

59. Continuity
Numerical models are a interpretation of the
groundwater flow regimen based on the available data.
Numerical modelers are water resources specialist which
“translate” the general aspects of the groundwater flow
regime into a numerical code.
Never two modelers will produce the same model with
same data set.

60. Continuity
It will the same as asking two
painters to paint the same
Mona Lisa.

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Open source software

62. Hydrologeology Software
MS MS EXCEL is an excelent spreadsheet,
But..
It is not a safe way store data.
It not a efficient way to retrieve data.
Do not allow effective collaboration of multiple partners.
Cannot be called a data base, it is just a place were your
data “is”.

63. Hydrologeology Software
Challenge: To migrate the data analysis with MS Excel to
different tool in GIS, numerical modeling, Python and
DBMS.
There is a full set of open source, high performance
software for hydrogeological studies.
If you want to reduce costs, why do you use commercial
software?

64. DraftSight
DraftSight lets professional CAD users, students and
educators create, edit and view DWG files. DraftSight
runs on Windows®, Mac® and Linux.
DraftSight is a drafting
automation software tool.
A coordinate system
determines each point of
a drawing surface or entity
unambiguously.
http://www.3ds.com/products/draftsight/overview/

65. Quantum GIS
Quantum GIS (QGIS) is a user friendly
Open Source Geographic Information
System (GIS) licensed under the GNU
General Public License.
QGIS is an official project of the Open
Source Geospatial Foundation (OSGeo).
It runs on Linux, Unix, Mac OSX,
Windows and Android and supports
numerous vector, raster, and database
formats and functionalities.
http://www.qgis.org

66. Quantum GIS
Quantum GIS provides a continously growing number of
capabilities provided by core functions and plugins. You
can visualize, manage, edit, analyse data, and compose
printable maps.

67. MODFLOW
MODFLOW is the software for
groundwater modeling developed by
the USGS.
The software is capable to represent
conditions related to the groundwater
flow as evapotranspiration, recharge,
drainage, river interaction among
others.
http://www.gidahatari.com/en/infohatari/learn-modflow-model-muse

68. MODFLOW
Its finite different approach gives the
capability to calculate the flow regime
with exceptional control on the water
budget discrepancy.
With MODFLOW one can rely that the
flow that is going in the model is the
same that the flow going out of the
model, from the regional scale and on
cross sections.

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Special thanks for his
collaboration on this presentation:
Dr. Campbell G. Fleming
Technical Director
EnviroCentre Limited

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Habt Iht Fragen?
Do you have questions?

71. Cost (& Time) Optimization
of Hydrogeological Studies
By:
Saul Montoya M.Sc.
March 2013