Cost (& Time) Optimization of Hydrogeological Studies


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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.

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Cost (& Time) Optimization of Hydrogeological Studies

  1. 1. Cost (& Time) Optimizationof Hydrogeological StudiesBy:Saul Montoya M.Sc.March 2013
  2. 2. www.gidahatari.comThis presentation is focused on:Strategies and best practices for cost(& time) optimization.Specially for hydrogeologicalinvestigation on mining projects
  3. 3. Mining HydrogeologyCurrently mining projects has to fulfill a series ofhydrogeological investigation along the mine life.Increasing concern about the environmentalimpacts.Hydrogeological investigations and numericalmodeling has to simulate, prevent and remediatethe mining impact to groundwater system andsurface water courses.
  4. 4. Mining HydrogeologyThere is continuity on the hydrogeologicalinvestigations. Results from the assessment fromone mine stage (feasibility) became an input for thenext stage.Source: Australian Government, Department of Resources,Energy and Tourism (2008)
  5. 5. Mining HydrogeologyImpact on the groundwater flow from miningfacilities could be evaluated many times alongs thedifferent mining phases.Many of these evaluation are done by differentconsultant companies.Sometimes two companies investigate the sameimpact at the same time.Challenge: Decrease the double effort!
  6. 6. www.gidahatari.comDas Ziel(the objective)
  7. 7. Water Management in MiningWater management in mining objectives are:• Assess all relevant aspects relevant to waterextraction, treatment, use and preservation.• Indentify all current and potential risks to naturalwater bodies from the mining activity.• Simulate and evaluate the impact from the minewater use to the other water users.
  8. 8. Water Management in MiningWater management plan characteristics:• Water-quality and water-quantity integration.• Incorporates site general hydrological conditions.• Has a detailed plan with responsibles andcalendars.• Plans with quantitative objectives rather thansubjective objective.• Has reports, operation procedures, and manuals.• It is dynamic, regularly rewieved and updated
  9. 9. www.gidahatari.comMain HydrogeologicalInvestigation in Mining
  10. 10. Mine Project Development• Baseline investigation on groundwater / surfacewater flow regimes.• Monitoring network design.• Groundwater impact assessment (quality andquantity) due to the mining project.• Mine water supply evaluation.• Pit inflows and mine drainage evaluation.• Predictive simulation of groundwater flow regimeon mine closure.
  11. 11. Mine Life• Water resources database management systemimplementation.• Surface water / groundwater monitoring systemupgrade.• Pit inflow / mine drainage modeling update.• Contaminant transport modeling from wastedumps and tailings deposits.• Upgrade of groundwater numerical models andresimulation of project impact.• Predictive simulation of groundwater flow regimeon mine closure.• Rules for site potential contaminant release.
  12. 12. Mine Closure• Water balance on closure conditions.• Assessment of the pit lake flooding time, finallevel and water quality.• Review of contaminant transport modeling onclosure conditions (Validation / Optimization).• Evaluation of natural attenuation on contaminanttransport evaluation.• Design of remediation plans.
  13. 13. www.gidahatari.comDas dinge an sich (Kant)The thing in itself
  14. 14. The thing in itselfPlan, plan and plan!
  15. 15. The thing in itself“Begin with end in mind”Habit 2 form the book “The 7 Habits Of Highly EffectivePeople” from Stephen R. CoveyBefore spending hours in any task one has tounderstand why the task is being conducted andhow it helps to meet the project need.
  16. 16. The thing in itselfFor cost optimization, you have to do the minimumrequired to effectively accomplish the goal you needto reach.In the end, it´s highlyabout money, money, money!
  17. 17. The thing in itselfTake 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 areidentified.
  18. 18. The thing in itselfDont be too optimistic about your times andbudgets.Once a contract is signed, it becomes very difficultto change the hydrogeological study scope or to askfor money and time.Insufficient planning and failed attempts tominimize costs led to effort duplication later on.
  19. 19. The thing in itself"If anything can go wrong,it will.“Murphys law
  20. 20. www.gidahatari.comFirst Step:Conceptual Modeling
  21. 21. Conceptual ModelingConceptual modeling is the first step on thehydrogeological investigations.The conceptual model is the degree ofunderstanding of the groundwater flow regime withthe available information.If the hydrogeological conceptual model (and thegeological conceptual model) are flawed everythingelse is flawed – design of the groundwater flowregime.
  22. 22. Conceptual ModelingWe can have a reasonable from a site and data withgood background on hydrogeology:
  23. 23. “Hydrical Eye”What everybody see versus what a hydrogeologist see.Cuenca, Manantialesy BofedalesAncashSpringsWetlandsPrecipitation asSnowNatural DrainsFuente:
  24. 24. Conceptual ModelingConceptual modeling is a tool. One have to build,review and improve it.A reasonable conceptual model from the beginninghelp focus on what data are most critical.All phases of the hydrogeological investigation willupdate the conceptual model.
  25. 25. Conceptual ModelingConceptual model will optimise well locations andinform the understanding of aquifer interactions.It is good to use the results of previous studies abasis for the investigation phases.The conceptual model is then “translated” to thenumerical model.
  26. 26. Conceptual ModelingGroundwater flow is spatially distributed, thereforeyou should build you conceptual model with GIStools (If you dont want to mess around with abunch of maps and reports).Save the trees!
  27. 27. www.gidahatari.comEinige Empfehlungen(some recomendations)
  28. 28. www.gidahatari.comField Investigation
  29. 29. Field InvestigationSeek for the opinion of a specialized group ofpeople early on the mine planning.Coordinate geotechnical and hydrogeologicalstudies. Both tasks can collaborate on the drillingand characterization efforts.
  30. 30. Field InvestigationWhy dont you install a piezometer on everygeotechnical drilling?It might be not suitable for groundwater qualitymonitoring but is okay for water levels andhydraulic tests.Baseline soil chemistry chemistry can be done atthe same time too. This information is also veryimportant for mine closure to show original soilsquality versus post-operational phase chemistry.
  31. 31. www.gidahatari.comMonitoring Network
  32. 32. Monitoring NetworkA minimum of 30 piezometers is required to have anormal distribution of water heads. However amining proyect in its early stages has fewer points.An optimized approach is to couple piezometricdata with baseflow gauging.This is a recommedation from the commonpractice: a monitoring network of 12 piezometers(>30m) plus 5 baseflow measurements will beenough to give a good understanding of thegroundwater flow regime.
  33. 33. Monitoring NetworkGroundwater levels and baseflow variation. How is the correlation with depthof installation.Source: DCNR
  34. 34. Monitoring NetworkHowever, the number of piezometers depends onscale of the development and complexity ofgroundwater regime.Mining project / consultants in Perú usually budgetfrom 8 to 12 piezometers that is limited tounderstand the groundwater flow regime. Ifmodellers ask for 30 there will be more chance toget 18 points.The bigger the water level / baseflow monitoringnetwork, the better understanding of thegroundwater flow regime.
  35. 35. Multilevel PiezometersMultilevel piezometers can describedifferent piezometric level with levelsat one location.These piezometers can give usefulinformation about anisotrophy,hydralic parameters and rechargemechanisms.Multilevel piezometer has not muchvalue without multilevel readings withtime (minimum one year). Source: Solinst
  36. 36. Multilevel PiezometersMultilevel reading requiere a moredetailed numerical modeling withtransient calibration. Betterestimation of K, Sy and Ss.If you plan to deliver a report in 6months, it is better to use one levelpiezometers.Source: Solinst
  37. 37. www.gidahatari.comField Sampling
  38. 38. Field SamplingDo a lot of sampling on the early stages of yourhydrological investigation.Analyze the spatial and temporal variability ofgroundwater levels and quality.Then optimize your piezometric network!
  39. 39. Field SamplingDynamic ofmonitoringnetworks
  40. 40. Field SamplingNobody has a university degree to:• Sample groundwater levels.• Measure groundwater ph, conductace andtemperature.• Use a flow meter, or reading a water scale.Hire local capacity!
  41. 41. Field Sampling
  42. 42. Field SamplingThere is balance in between the water levelsampling frecuency and error on the measurement.The lower the cost, the higher the error.
  43. 43. www.gidahatari.comPumping Tests
  44. 44. Pumping TestsUsually one has to quote supervisors 24 hours, plus agenerator in backup.High uncertainty on the results and interpretation ifpumping is interrupted.
  45. 45. Pumping TestsGraphical interpretation of pumping test comes from the70’s were computational power was scarce.Software for pumping testinterpretation do not takeinto account anysotropy,incontinuos layering andvarying pumping schedule.
  46. 46. Pumping TestsPumping test interpretation with numerical modelinggives you flexibility to:• Turn on, turn off, increase / decrease pumping ratesseveral times as long as you record the pumpingschedule and rate.• Only need a operator to fuel the generator.… that decreases the cost of the pumping test!
  47. 47. Pumping TestsNowadays submersible pumps are moreslim.2” submersible pumps can perform pumpingtests on 4” piezometers… that increases the availability of thepumping locations!
  48. 48. www.gidahatari.comDie Helden (The Heroes) :GroundwaterNumerical Models
  49. 49. Numerical ModelingGroundwater numerical models are not a “trendy”,“stylish” or “fashionable” part of the hydrogeologicalreport.Groundwater model are the best tools available tounderstand the fate and transport of the groundwaterflow regime.We have to see groundwater models as a managementtool.
  50. 50. Numerical ModelingDetermine the need fornumerical modeling.Select the right code to fulfillthe investigation objectives.Specify the level of detail of thenumerical modelCompile all relevant data beforedetailed modeling.
  51. 51. Numerical ModelingNumerical models need a good conceptual foundation.Otherwise numerical model becomes a “black box”bringing “rubbish” water head and concentrations thatlooks great on maps and cross sections.
  52. 52. Numerical ModelingUsual hydrogeological study secuence:Optimized hydrogeological study secuence:DataCompilationFieldInvestigationDataAnalysisNumericalModelingImpactEvaluationDataCompilationCoarseNumericalModelingFieldInvestigationDataAnalysisFineNumericalModelingImpactEvaluation
  53. 53. Numerical ModelingAdvantaje of the optimized hydrogeological studysecuence:• Coarse numerical modeling strength the conceptualmodeling.• More flexibility to identify “hotspots” in the area ofstudy.• Optimization of the drilling program.• More time for data analysis.
  54. 54. www.gidahatari.comDer Anschluss (The Continuity) onHydrogeological Studies
  55. 55. ContinuityWhen working with data these are the percetanjes oftime spent on related tasks:Data compilation can be reduced to 15% if there is acontinuity on the staff related to the investigation andthe implementation of DBMS (Data Base ManagementSystems).… that means a time saving of 25% on the cabinettasks.DataCompilation40%DataAnalysis20%NumericalModeling40%
  56. 56. ContinuityWe have to assure the quality of the hydrogeologicalstudies.Background knowledge is critical to supervise the workof consultants, field monitoring staff and even reviewers.Change of consultants only good practice when theproduced studies do not fit the regulatory officialrequirements.Never change of consultants without a good reason,since there will be a “gap” on the data and theconceptual model… that means more time consumed.
  57. 57. ContinuityFor cost optimization, the consultant company that runs aregional model should be the same the one in charge of thelocal numerical modeling (tailings dam, pit).Many consultant companies running modeling work on parallelmostly turn on effort duplication, low comunication anddifferent approaches of the groundwater flow regime.… but why?
  58. 58. ContinuityThe UnknownAs we know,There are known knowns.There are things we know we know.We also knowThere are known unknowns.That is to sayWe know there are some thingsWe do not know.But there are also unknown unknowns,The ones we dont knowWe dont know.D.H. Rumsfeld, Feb. 12, 2002,Department of Defense news briefing
  59. 59. ContinuityNumerical models are a interpretation of thegroundwater flow regimen based on the available data.Numerical modelers are water resources specialist which“translate” the general aspects of the groundwater flowregime into a numerical code.Never two modelers will produce the same model withsame data set.
  60. 60. ContinuityIt will the same as asking twopainters to paint the sameMona Lisa.
  61. 61. www.gidahatari.comOpen source software
  62. 62. Hydrologeology SoftwareMS 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 yourdata “is”.
  63. 63. Hydrologeology SoftwareChallenge: To migrate the data analysis with MS Excel todifferent tool in GIS, numerical modeling, Python andDBMS.There is a full set of open source, high performancesoftware for hydrogeological studies.If you want to reduce costs, why do you use commercialsoftware?
  64. 64. DraftSightDraftSight lets professional CAD users, students andeducators create, edit and view DWG files. DraftSightruns on Windows®, Mac® and Linux.DraftSight is a draftingautomation software tool.A coordinate systemdetermines each point ofa drawing surface or entityunambiguously.
  65. 65. Quantum GISQuantum GIS (QGIS) is a user friendlyOpen Source Geographic InformationSystem (GIS) licensed under the GNUGeneral Public License.QGIS is an official project of the OpenSource Geospatial Foundation (OSGeo).It runs on Linux, Unix, Mac OSX,Windows and Android and supportsnumerous vector, raster, and databaseformats and functionalities.
  66. 66. Quantum GISQuantum GIS provides a continously growing number ofcapabilities provided by core functions and plugins. Youcan visualize, manage, edit, analyse data, and composeprintable maps.
  67. 67. MODFLOWMODFLOW is the software forgroundwater modeling developed bythe USGS.The software is capable to representconditions related to the groundwaterflow as evapotranspiration, recharge,drainage, river interaction amongothers.
  68. 68. MODFLOWIts finite different approach gives thecapability to calculate the flow regimewith exceptional control on the waterbudget discrepancy.With MODFLOW one can rely that theflow that is going in the model is thesame that the flow going out of themodel, from the regional scale and oncross sections.
  69. 69. www.gidahatari.comSpecial thanks for hiscollaboration on this presentation:Dr. Campbell G. FlemingTechnical DirectorEnviroCentre Limited
  70. 70. www.gidahatari.comHabt Iht Fragen?Do you have questions?
  71. 71. Cost (& Time) Optimizationof Hydrogeological StudiesBy:Saul Montoya M.Sc.March 2013