LECTURE 9PUMP-AND-TREAT SYSTEMSPump and Treat TechnologyPrinciples of Pump and TreatMMR Containment of CS-4 Plume by Pump & TreatLaPlace’s Equation for 2-D Flow in a Confined AquiferFlow Net ConstructionUniform FlowFlow to WellFlow to Well in Uniform FlowFlow to Well in Uniform FlowFlow Chart for Capture Well DesignInjection and withdrawal well pairOptimizing Pump-and-Treat2-minute Intro to Linear ProgrammingLinear programming formulationCapture Well Design OptimizationMODOFC Optimization CodePumping Well ConstructionWell ScreenGrain Size Sieve AnalysisScreen Size from Grain SizeScreens for stratified aquifersWell efficiencyStep-Drawdown TestWell loss theoryStep-Drawdown AnalysisVertical Turbine Well PumpsEductor pumpsAir Stripping TowerCatalytic Oxidizer for Vapor ExhaustThermal OxidizerThermal OxidizerGranular Activated Carbon (GAC)Activated CarbonMetals Removal - PrecipitationMetals Removal – Iron CoprecipitationOil Water SeparatorLECTURE 9PUMP-AND-TREAT SYSTEMSPump and Treat TechnologyGoals:1. Hydraulic containment of contaminated ground waterPrevent contamination from spreading to uncontaminated areas2. Treatment of contaminated ground waterReduce concentrations in ground water to below cleanup standards (MCLs)Reference: U.S. EPA, 1996. Pump-and-Treat Ground-Water Remediation: A Guide for Decision Makers and Practitioners. Report Number EPA/625/R-95/005. U.S. EPA, Office of Research and Development, Washington, DC.Figure 2. Remedy Types Selected at Sites on the National Priorities List (FY 1982 - FY 1999)P&Tf (576)41%Source Controla (326)22%Groundwater-Other Remedy Onlyb (33)2%MNAc (92)6%P&T and In Situ Treatment of Groundwater (62)4%In Situ Treatment of Groundwatere (19)1%Groundwater Containmentd (5)<1%No Action or No Further Action (102)7%No ROD Issued Through FY 1999 (236)17%Total Number of Sites = 1,451Sites with Groundwater Remedies = 787 (54%)Sources: 1, 2, 3, 4, 5, 6, 8. Data sources are listed in the References and Data Sources Section on p. 17.P&T = Pump and treatMNA = Monitored natural attenuationIld h l d l db d P&T MNA d l dSource: U.S. EPA, 2002. Groundwater Remedies Selected at Superfund Sites. Report No. EPA-542-R-01-022. Office of Solid Waste and Emergency Response, U.S. EPA, Washington, D.C. January 2002.Principles of Pump and TreatQ = K i A = flow in aquifer defined by Darcy’s Law [L3/T]K = hydraulic conductivity [L/T]i = hydraulic gradient [L/L]A = cross sectional area in aquifer [L2]C = concentration in the ground water [M/L3]QC = mass flux [M/T]= K i A CU.S. EPA, 1996. Pump-and-Treat Ground-Water Remediation: A Guide for Decision Makers and Practitioners. Report Number EPA/625/R-95/005. U.S. Environmental Protection Agency, Office of Research and Development, Washington, D.C. July 1996. WellTrenchMMR Containmentof CS-4 Plume by Pump & TreatSource: http://www.mmr.org/irp/plans/cip/maps/cs4_02.htmMMR CleanupProposal for FS-1 Plume by Pump & TreatSource: http://www.mmr.org/cleanup/plumes/fs1/fs1699.htmLaPlace’s Equation for 2-D Flow in a Confined AquifertSyxT2222∂φ∂=⎟⎟⎠⎞⎜⎜⎝⎛∂φ∂+∂φ∂xyTQ∂φ∂δ−=δT = transmissivityS = storage coefficientφ = potential functionxyyx ∂ψ∂−=∂φ∂∂ψ∂=∂φ∂δQ = flow incrementψ = streamfunctionFlow Net ConstructionA Portion of a Flow Netn1S1QS2n2Qfffff000++2yyy0y0y0++2Uniform Flow()α+α−=φsinycosxITqI =Potential function()α−α−=ψsinxcosyIStream functionq = flow per unit widthT = tranmissivityStream Function and Potential Function for Uniform FlowYXy= -2Iy= -Iy= 0y= I= 3If= 2If= If= 0f= -If= -2IfaFlow to Well⎥⎦⎤⎢⎣⎡−+−π=φ2w2020wr)yy()xx(lnT4Q⎥⎦⎤⎢⎣⎡−−π=ψ−001wxxyytanT2QPotential functionStream functionrw= well radiusx0, y0= well locationStream Function and Potential Function for Flow to a Pumping Well=34XYppyQw2 T=4ppyQw2 T=54ppyQw2 T=74ppyQw2 T=2ppyQw2 Ty= 0f1f2f3f4Flow to Well in Uniform FlowSuperpositionof solutionsfor uniformflow and wellImage adapted from: Bear, J. Hydraulics of Groundwater. New York: McGraw-Hill International Book Company, 1979.Flow to Well in Uniform Flow∑∑=−=⎥⎦⎤⎢⎣⎡−−π+α−α−=ψ⎥⎦⎤⎢⎣⎡−+−π+α+α−=φn1iii1in1i2i2i2iixxyytanT2Q)sinxcosy(Ir)yy()xx(lnT4Q)sinycosx(In = number of wellsxi, yi= location of well iNote: solution is implicit in x and yCapture zoneiTQWW=iT2πQxWs=⎟⎟⎠⎞⎜⎜⎝⎛π±=wQTiy2tanxyCapturewidthStagnationpointNote change innotation:BU = TiRegional Flow1000-100050000-500-500 500MetersMeters1000 1500 2000 2500XYAdapted from: Javendel, I. and C.-F. Tsang. "Capture-Zone Type Curves: A Tool for Aquifer Cleanup."Ground Water 24, no. 5 (1986): 616-625.Single-Well Capture-Zone Type CurvesQ/BU = 2000 mQ/BU = 1600 mA set of type curves showing the capture zones of a single pumping well located at the origin for various values of (Q/BU).Q/BU = 1200 mQ/BU = 800 mQ/BU = 400 mNote: each well has pumping rate Q05000500XY-500-500Meters1: A set of type curves showing the capture zones of two pumping wells located on the y-axis for various valuesof (Q/BU).Meters-1500-100010001000150015002000 2500 300005000500XY-500-500MetersMeters-1500-100010001000150015002000 2500 3000Adapted from: Javendel, I. and C.-F. Tsang. "Capture-Zone Type Curves: A Tool for Aquifer Cleanup." Ground Water 24, no. 5 (1986): 616-625.Q/BU = 2000 mQ/BU = 1600 mQ/BU = 400 m Q/BU = 800 m Q/BU = 1200 mQ/BU = 1000 mQ/BU = 800 mQ/BU = 200 m Q/BU = 400 m Q/BU = 600 mDouble-Well Capture-Zone Type CurvesThree-Well Capture-Zone Type Curves2: A set of type curves showing the capture zones of three wells located on the y-axis for various valuesof (Q/BU).Regional FlowRegional FlowNote: each well has pumping rate QNumber of Pumping WellsOptimum Distance Between Each Pair of Pumping WellsDistance Between DividingStreamlines at the Line of WellsDistance Between Streamlines FarUpstream from the WellsOneTwoThreeQ2BUQBUQBUQBU3Q2BU3QBU2QBUpQBUp23Some Characteristic Distances in Flow Regimes for One, Two, and Three Pumping Wells Under a Uniform Regional Ground-Water FlowWell separation =1.1 Q/pTiSomeflow getsthroughWell separation =0.94 Q/pTiAll flowcaptured(in theory)Flow Chart for Capture Well Design1) Q = TI W4) Q = Q + Q2) x0 = Q/(2 TI)2 TI3) y = -x tan Equations Flow ChartFlow Chart and Equations for Basic Containment StrategypppQy((V6) Qw = 5) s = Q w4 TW(u) Qn7) n = n+1Calculate Plume DischargeCalculate Position of Limiting FlowlineDoes notEncompass Plume---